Question about 1998 Lincoln Navigator

Open Question

Code p1838 transfer case shift motor fault

Posted by Anonymous on

Ad

2 Suggested Answers

6ya6ya
  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi,
A 6ya expert can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
The service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.
Good luck!

Posted on Jan 02, 2017

Ad
  • 1168 Answers

SOURCE: 1998 linclon navigator will not go into 4 wheel

Hello.
I replace the vacuum solenoids on these models regularly.
Here is where they are located. #4 at the top.The vacuum reservoir is #3.
Make sure there are no broken lines.
These solenoids are known for corrosion due to their location.

kiltylake_62.gif

Here is the vacuum diagram for the system.
kiltylake_63.gif
There you are. That should take care of your problem.
Thank you for using FixYa.

KL

Posted on Dec 01, 2010

Ad

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

1 Answer

1998 chevy blazer four wheel drive not engageing


You replaced all those parts without knowing what is wrong , you like making parts stores rich ? Did you have it checked for DTC'S - diagnostic trouble codes ?
Transfer Case Control Module Description
The TCCM performs the following functions:
• Receives input signals
• Processes the signal information
• Develops output signals
• Sends the output signal in order to control the shifting of the transfer case
The TCCM receives input signals from the following sources:
• The transfer case shift select buttons
• The NSBU switch on the vehicles with automatic transmissions
• The clutch position switch on the vehicles with manual transmissions
• The vehicle sped sensor calibrator module
• The encoder/motor range and the mode feedback signals
• The diagnostic enable
• The front axle mechanical status signal
In order to ensure the electronic shift system is operating properly, the transfer case control module (TCCM) continually performs diagnostics checks on itself and other parts of the electronic shift system when the ignition switch is in the run position. The following are different types of system checks that the TCCM continually performs.

Motor and Relay Voltage Checks
Whenever the electric-shift motor is turned ON or OFF the motor and the electrical circuits are tested both in the de-energized and energized condition. If one or both voltage relays fail to detect the proper voltage after energizing or de-energized and energized condition. If one or both of the voltage relays fail to detect the proper voltage after energizing or de-energizing, the shift is aborted by the TCCM and a DTC of 3 is stored in order to indicate a faulty TCCM motor circuit.
If one or both relays fail to detect the proper voltage after de-energizing, both relays are turned ON by the TCCM, (even with the ignition switch positioned OFF) in order to prevent the motor from running. The TCCM then stores a DTC of 3 in order to indicate a faulty TCCM motor circuit. All of the status lamps blink three times, stop, and repeat the blinking continuously in order to alert the driver that the electronic shift system requires immediate repair. The battery will drain when this condition occurs, regardless of the ignition switch position.

DTC 001
DTC 002
DTC 003
DTC 004

DTC 001
The transfer case shift control module normally has battery voltage supplied to it at all times through the battery positive voltage circuit (CKT 40). When the ignition is ON, the transfer case shift control module conducts a self-test to determine if it retains the same memory it had when the ignition was last turned OFF. This self-test indicates whether the RAM standby power supply to the transfer case shift control module pin C6 was interrupted, which would result in clearing DTC's from memory. If the self-test fails the transfer case shift control module sets DTC 1.
Inspect the CTSY LP fuse for an open.

DTC 002
The transfer case encoder motor is an assembly which houses four separate channels. These channels are used to indicate to the transfer case shift control module the present gear position of the transfer case or if the transfer case is in transition between gears. The encoder motor assembly consists of an electronically conductive inner ground ring in contact with a three legged wiper arm. Each leg's length is such that it makes contact with the conductive regions of the four channels. When any leg of the wiper arm is making contact with the conductive area of any channel, the encoder provides a path to ground to the inner ground ring.
During electronic shifting, the transfer case shift control module monitors the transfer case encoder circuit for the proper operating sequence. If at any time during a shift, the encoder changes from one position to any position other than the next possible position, an error counter in the transfer case shift control module increments by four. After the counter reaches 32, the transfer case shift control module set a DTC 2, a permanent "encoder fault," and reverts to a 2HI to 4LO or a 4LO to 2HI shift pattern only. To guard against a transient, random encoder fault due to vibration, dirt, electrical noise, etc., the fault counter reduces by one each time the transfer case shift control module detects a valid encoder value. The encoder must intermittently fail 25 percent of the time for the transfer case shift control module to consider it faulty and store DTC 2.

DTC 003
Circuit Description
The transfer case encoder motor has a bi-directional, permanent magnet, D.C. motor. When energized, (through Motor Control A or Motor Control B, the ground is provided by the opposing motor control circuit and then grounded through the transfer case shift control module ground circuit), the motor, through a series of gears, rotates a shaft which moves the mode and range forks to shift the transfer case between 4H, 2HI, and 4L ranges.
This DTC detects a short or open in the battery positive voltage circuit (CKT 1640), ground circuit, an internal short in the motor windings and related circuitry, or an internal transfer case shift control module failure.
Action Taken When the DTC Sets
In the event that one of the motor control circuits is energized (battery voltage is applied) the transfer case shift control module will energize the other motor control circuit to keep the motor from running. All switch indicator lamps will flash continuously to prompt the driver that service is required. The transfer case system will be disabled and the transfer case shift control module will remain energized even with the ignition in the OFF position.
Conditions for Clearing the DTC
The condition for setting the DTC is no longer present and a momentary loss of battery power at the battery positive voltage circuit (CKT 40).
Diagnostic Aids
When the vehicle is equipped with a manual transmission the clutch pedal must be depressed and working correctly in order for the transfer case to shift to the 4 low position. In order to confirm that it is operating correctly go the engine data 1 screen under the engine data display and observe the clutch pedal switch parameter.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
This step tests the battery positive voltage circuit (CKT 1640) for an open or high resistance.
This step inspects the ATC fuse for an open.
This step tests the ground circuit.
This step tests the Motor Control A and B circuits.
DTC 3 -- TCCM Motor Circuit Step
Action
Value(s)
Yes
No
1
Important: Check the transfer case shift control module for DTCs. The transfer case shift control module is not a class 2 device. DTCs are displayed on the transfer case shift control switch. Use the following four steps to obtain DTCs.
Turn OFF the ignition for 10 seconds.
Connect PIN 13 on the data link cable (DLC) to a ground. The DLC is located in the cab under the instrument panel on the driver's side.
Turn ON the ignition, with the engine OFF.
Observe the transfer case shift control switch select buttons for flashing codes.
Did you perform A Diagnostic System Check - Transfer Case?
--
Go to Step 2
Go to Diagnostic System Check
2
Turn ON the ignition, with the engine OFF.
Backprobe and measure battery positive voltage (CKT 1640) at the transfer case shift control module.
Does the voltage measure near the specified value?
B+
Go to Step 6
Go to Step 3
3
Inspect the ATC Fuse 20A.
Is the fuse blown?
--
Go to Step 5
Go to Step 4
4
Repair the battery positive voltage circuit (CKT 1640) for an open or high resistance. Refer to General Electrical Diagnosis and Wiring Repairs in Wiring Systems.
Did you complete the repair?
--
Go to Step 11
--
5
Repair the battery positive voltage circuit (CKT 1640) for a short to voltage or short to ground. Refer to General Electrical Diagnosis and Wiring Repairs in Wiring Systems.
Replace the ATC Fuse.
Did you complete the repair?
--
Go to Step 11
--
6
Connect a test lamp from the battery positive voltage circuit (CKT 1640) to the ground circuit at the transfer case shift control module.
Does the test lamp illuminate?
--
Go to Step 8
Go to Step 7
7
Repair the ground circuit for an open or high resistance. Refer to General Electrical Diagnosis and Wiring Repairs in Wiring Systems.
Did you complete the repair?
--
Go to Step 11
--
8
Backprobe and measure voltage at the transfer case shift control module between the transfer case motor control A circuit and the transfer case motor control B circuit.
Press the 4HI then 4LO on the shift control switch.
The DMM should read +12V in one direction and -12V in the other direction.
Does the voltage measure near the specified value?
+12V/-12V
Go to Step 9
Go to Step 10
9
Repair the open or high resistance in the transfer case motor control A or B circuits. Refer to General Electrical Diagnosis and Wiring Repairs in Wiring Systems. If OK, replace the transfer case encoder motor. Refer to Motor/Encoder Replacement .
Did you complete the repair?
--
Go to Step 11
--
10
Replace the transfer case shift control module. Refer to Transfer Case Shift Control Module Replacement .
Did you complete the replacement?
--
Go to Step 11
--
11
Clear all DTCs from memory. Refer to Diagnostic Trouble Code (DTC) Clearing .
Operate the vehicle while pressing each of the buttons on the transfer case shift control switch.
Does the DTC reset?
--
Go to Step 2
System OK

There is a bit more to it then just replacing parts ! Your best bet - Take it to a qualified repair shop .

Feb 07, 2017 | Chevrolet Blazer Cars & Trucks

1 Answer

How do I repair the four wheel drive on a 1999 Ford Ranger XLT?


It depends on what is wrong , is the 4x4 light flashing ? Are you aware of the complexity of the 4x4 system ? Has a electronic control module , has the ability to set an store DTC'S - diagnostic trouble codes !
Transfer Case The four wheel drive system is an electronic shift 4X4 system that allows the operator to choose between three different modes. The operator can switch 4X4 HIGH modes at any speed. To engage or disengage 4X4 LOW the vehicle speed must be less than 5 kph (3 mph), the brake depressed, and the transmission must be in NEUTRAL.
The shift motor sense plate, an integral part of the electronic shift motor, informs the generic electronic module (GEM) of the transfer case shift motor and contact plates A, B, C and D position.
The digital transmission range (TR) sensor is located on the LH side of the transmission, and informs the GEM when the transmission is in the NEUTRAL position.
The electronic shift motor is mounted externally at the rear of the transfer case. It drives a rotary cam which moves the mode fork and range fork within the transfer case between the 4X4 HIGH, 4X4 LOW and 2WD range positions.
When the GEM verifies the completion of the transfer case shift from 2WD to 4X4 HIGH (reading the contact plate positions), the GEM will then energize both pulse vacuum hublock (PVH) solenoids (supplying ground for 45 seconds). The PVH solenoid will allow a HIGH flow of intake manifold vacuum to the "wheel end hublocks", engaging the wheel end hubs to the front differential and transfer case to achieve four wheel drive.
Here are just a few DTC'S the system can set an store in the module !
P1804 4WD High Indicator Circuit Failure GEM GO to Pinpoint Test C . P1806 4WD High Indicator Short to Battery GEM GO to Pinpoint Test C . P1808 4WD Low Indicator Circuit Failure GEM GO to Pinpoint Test C . P1810 4WD Low Indicator Short to Power GEM GO to Pinpoint Test C . P1812 4WD Mode Select Switch Circuit Failure GEM GO to Pinpoint Test A . P1815 4WD Mode Select Switch Circuit Short to Ground GEM GO to Pinpoint Test A . P1820 Transfer Case CW Shift Relay Circuit - Failure GEM GO to Pinpoint Test A . P1822 Transfer Case CW Shift Relay Coil Short to Power GEM GO to Pinpoint Test A . P1824 4WD Electric Clutch Relay Circuit Failure GEM GO to Pinpoint Test A . P1826 4WD Low Clutch Relay Short to Power GEM GO to Pinpoint Test A . P1828 Transfer Case CCW Shift Relay Coil Circuit Failure GEM GO to Pinpoint Test A . P1830 Transfer Case CCW Shift Relay Coil Short to Battery GEM GO to Pinpoint Test A . P1838 Transfer Case Shift Motor Circuit Failure GEM GO to Pinpoint Test A . P1846 Transfer Case CONTACT PLATE "A" Circuit Failure GEM GO to Pinpoint Test A . Now are you sure you really want to mess with this ? You would need a factory diagnostic scan tool to check this out before you start replacing parts !
Here

May 30, 2015 | Ford Ranger Cars & Trucks

1 Answer

I have a 1998 Chevy Tahoe I tryed to put my truck is 4wd low and it tryed and keep on blinking and went back to 2wd and blow a fuse and I tryed again and did it again but then the the service 4wd light...


Which 4X4 system does your tahoe have ?
Transfer Case System Description (Selectable 4WD)
The New Venture Gear Model NV243 is an electronically controlled optional transfer case for use on four wheel drive K trucks. The driver selects 2HI, 4HI, or 4LO by pushing one of three illuminating shift select buttons mounted on the instrument panel. The shift select buttons display the transfer case mode and range, self-test, diagnostic trouble codes, and electronic shift mechanical engaging problems.

Transfer Case System Description (Automatic 4WD)
The two speed Auto transfer case system utilizes a part time front axle. The system allows the driver to select the transfer case position with a touch of a button. The following positions can be selected: 4-wheel drive high range (4H), All Wheel Drive (AUTO), 2 Wheel Drive high range (2H), Neutral (N), and 4-Wheel Drive low range (4L).
The Auto Transfer Case (ATC) Control Module controls all the shifting action of the transfer case based on input from the driver as well as information from the Vehicle Control Module (VCM) /Powertrain Control Module (PCM).
4WD (4H or 4L) mode: This is accomplished by engaging the front axle, applying PWM to an electric motor to apply maximum torque, (fully compressing the transfer case clutch plates) to the front axle, then removing the ground on circuit 1569, thus locking the motor in position and stop the PWM to the motor.
AUTO mode: When in this mode of operation, the system should engage the front axle, then it monitors the front and rear propshaft speeds for any speed differences. When the system senses rear wheel slip, a difference of propshaft speed between front and rear, the Auto Transfer Case (ATC) Control Module will use pulse width modulation (PWM) to drive an electric motor. This motor transfers only the required torque to the front wheels to gain additional traction on slippery surfaces up to 75 mph. There is no torque applied to the front wheels until the module senses rear wheel slip.
Throttle anticipation (only operational when in AUTO mode): If the vehicle is below 5 mph and the accelerator is pressed quickly beyond a set point, the system will automatically transfer a percentage of torque to the front wheels to help prevent the rear wheels from slipping, as in a hard acceleration from a stopped position.
The Auto Transfer Case (ATC) Control Module also has the capability of engaging the front axle while the vehicle is in motion. It does this by applying PWM to the electric motor to apply torque to the front axle, this action is used to match the speed of the front and rear propshafts. After the module senses the proper speed, it then supplies a ground on circuit 1570 to engage the front axle.
The Auto Transfer Case (ATC) Control Module will accept a mode shift only when the engine is running and a valid Motor/Encoder signal is present. A mode shift is any shift between 2H, 4H, and AUTO.
The Auto Transfer Case (ATC) Control Module will permit a range shift only if the following conditions are met within 30 seconds of the request:

Automatic 4WD Diagnostic Aids
A Scan Tool reads and displays the following information:
• Diagnostic Trouble code(s)
• Code status bit (are codes set or not)
• Transfer case lock status
• Lamp in the switch/lamp assembly
• Motor/Encoder gear position
• Ignition (3) voltage
• Front propshaft speed sensor (KPH)
• Front axle switch (open/closed)
• Front axle requested position (engaged/disengaged)
• Rear propshaft speed sensor (KPH)
• Mode switch position request
• Park switch (open/closed)
• 4WD (Adapt) Mode Auto bit
• Current Mode corrective action PWM
• Average and highest PWM applied during last slip recovery event
• Throttle anticipation mode
• Average and highest PWM applied during last Throttle anticipation corrective action event
• Difference between front and rear propshaft RPM
• Adapt event counter
• Throttle position sensor percentage

Check the transfer case shift control module for DTC's. The transfer case shift control module is not a class 2 device. DTC's are displayed on the transfer case shift control switch. Refer to Diagnostic Trouble Code (DTC) Displaying .
Are any DTC's present?
Diagnostic Trouble Code (DTC) Displaying
The transfer case shift control module is equipped with the ability to store diagnostic information, which is useful to a technician in the event of module, component or wiring failures. This information can be retrieved from the transfer case shift control module by way of flash codes, which are displayed on the three transfer case shift control switch buttons. These buttons are located on the instrument panel to the right of the steering wheel Before obtaining DTCs, perform the following transfer case control module (TCCM) Self-Test.
TCCM Self-Test
Observe the transfer case shift control switch indicators while turning the ignition switch to RUN. A properly operating system will flash all indicators and then will return to the current gear. If the system is operating normally, then proceed to Displaying Codes.
If the TCCM failed the Self-Test, then test the following circuits.
• Battery Positive Voltage (40 and 1640), and Ignition 3 Voltage for battery voltage
• Ground Circuit for ground
• Diagnostic enable circuit for an open or high resistance
• Transfer case shift control switch connector
If the above circuits are normal but the TCCM still fails the Self-Test, replace the TCCM. Refer to Transfer Case Shift Control Module Replacement .
DTC Displaying
Turn OFF the ignition for 10 seconds.
Connect PIN 13 on the data link cable (DLC) to a ground. The DLC is located in the cab under the instrument panel on the driver's side.
Turn ON the ignition, with the engine OFF.
Observe the transfer case shift control switch select buttons for flashing codes. Refer to Diagnostic Trouble Code (DTC) List .
Important: If the transfer case shift control switch buttons all blink only once and then stop, no fault codes are stored in the transfer case shift control module.
• When one DTC is stored in memory, that code will blink that number of times followed by a 3 second pause and then repeat.
• If more than one code is stored, the first code will blink, followed by a 3 second pause and then the second code will blink.
• This sequence will continue until PIN 13 on the DLC is no longer grounded.
• If the TCCM will not communicate the presence or absence of DTCs, test the above circuits in Self-Test Step 2. If the circuits are complete, then replace the TCCM. Refer to Transfer Case Shift Control Module Replacement .

Apr 15, 2017 | Cars & Trucks

2 Answers

4x4high and 4x4 low indicator lights cycle on and off 6 times while driving shortly after starting driving


If lights are on, trouble codes are stored. Get he codes read. That's always the starting point.

Dec 05, 2017 | 1998 Ford Explorer

1 Answer

4x4 low light on car will not move


The electronic module (located behind the glove compartment) controls the operation of the transfer case in response to inputs from the electric shift motor, 4x4 mode switch, CPP switch, BPP switch, DTR sensor, throttle position output from the PCM, front and rear OSS sensors, and the VSS. Do you know what DTC'S Are ? Diagnostic trouble codes !

P1804 4WD High Indicator Circuit Failure GEM GO to Pinpoint Test C . P1806 4WD High Indicator Short to Battery GEM GO to Pinpoint Test C . P1808 4WD Low Indicator Circuit Failure GEM GO to Pinpoint Test C . P1810 4WD Low Indicator Short Circuit to Battery GEM GO to Pinpoint Test C . P1812 4WD Mode Select Circuit Failure GEM GO to Symptom Chart. P1815 4WD Mode Select Short Circuit to Ground GEM GO to Symptom Chart. P1820 Transfer Case CW Shift Relay Coil Circuit Open or Short to Ground GEM GO to Pinpoint Test B . P1822 Transfer Case CW Shift Relay Coil Short to Battery GEM GO to Pinpoint Test B . P1824 4WD Electric Clutch Relay Circuit Failure GEM GO to Pinpoint Test A . P1826 4WD Electric Clutch Relay Short to Battery GEM GO to Pinpoint Test A . P1828 Transfer Case CCW Shift Relay Circuit Failure GEM GO to Pinpoint Test B . P1830 Transfer Case CCW Shift Relay Coil Short to Battery GEM GO to Pinpoint Test B . P1836 Transfer Case Front Shaft Speed Sensor Circuit Failure GEM GO to Symptom Chart. P1837 Transfer Case Rear Shaft Speed Sensor Circuit Failure GEM GO to Symptom Chart. P1838 Transfer Case Shift Motor Circuit Failure GEM GO to Pinpoint Test B . P1846 Transfer Case CONTACT PLATE "A" Circuit Failure GEM GO to Pinpoint Test B . P1850 Transfer Case CONTACT PLATE "B" Circuit Failure GEM GO to Pinpoint Test B .

P1854 Transfer Case CONTACT PLATE "C" Circuit Failure (GEM Only) GEM GO to Pinpoint Test B . P1858 Transfer Case CONTACT PLATE "D" Circuit Failure (GEM Only) GEM GO to Pinpoint Test B . P1866 Transfer Case Maintenance Required (GEM Only) (4-wheel drive operation can be restored by clearing the DTC and cycling the ignition.) GEM GO to Pinpoint Test B . P1867 Transfer Case Contact Plate General Circuit Failure (GEM Only) GEM GO to Pinpoint Test B . P1874 Automatic Hall Effect Sensor Power Circuit Failure GEM GO to Symptom Chart. P1875 Automatic Hall Effect Sensor Power Circuit Short to Battery (GEM Only) GEM GO to Symptom Chart. P1891 Transfer Case Contact Plate Ground Return Open Circuit GEM GO to Pinpoint Test B Your best bet , take it to a qualified repair shop

Apr 04, 2017 | 2002 Ford Explorer

1 Answer

2002 f150 4wd drive not not working,


Transfer Case - Electronic Shift on the Fly (ESOF) Features A rotary switch allows the vehicle operator to choose between 2WD, 4H, and 4L modes of 4x4 operation.
The generic electronic module (GEM) controls the operation of the 4x4 system.
The output shaft speed (OSS), mounted in the rear of the transfer case, informs the GEM of the vehicle speed.
The shift motor sense plate, an integral part of the electronic shift motor, informs the GEM to the positions of the transfer case (go to Table 4).
The transmission range sensor is located on the LH side of the transmission; this sensor informs the GEM when the transmission is in the NEUTRAL position.
The electronic shift motor, mounted externally at the rear of the transfer case, drives a rotary cam which moves the mode fork and range fork within the transfer case to select between the 2WD, 4H, and 4L positions.
The 4x4/4x2 vacuum solenoids are attached to the upper RH side of the engine compartment, and alternately route vacuum to the vacuum motor which engages/disengages the center axle disconnect collar in the front axle assembly.
The 4x4 shift motor relay is a module containing two relays. Under the control of the GEM, the 4x4 shift motor relay shifts the transfer case shift motor between the 2WD, 4H, and 4L modes.
The transfer case clutch relay is an electromechanical relay used to activate the transfer case clutch within the transfer case.


Your best bet , take it to a qualified repair shop !

P1804 Transmission 4-Wheel Drive High Indicator Circuit Failure GEM REFER to Section 413-01A . P1806 Transmission 4-Wheel Drive High Indicator Short Circuit to Battery GEM REFER to Section 413-01A . P1812 Transmission 4-Wheel Drive Mode Select Circuit Failure GEM REFER to the Symptom Chart. P1815 Transmission 4-Wheel Drive Mode Select Short Circuit to Ground GEM REFER to the Symptom Chart. P1820 Transmission Transfer Case Clockwise Shift Relay Coil Circuit Failure GEM GO to Pinpoint Test A . P1822 Transmission Transfer Case Clockwise Shift Relay Coil Short Circuit to Battery GEM GO to Pinpoint Test A . P1824 Transmission 4-Wheel Drive Clutch Relay Circuit Failure GEM GO to Pinpoint Test E . P1826 Transmission 4-Wheel Drive Low Clutch Relay Short Circuit to Battery GEM GO to Pinpoint Test E . P1828 Transmission Transfer Case Counter Clockwise Shift Relay Coil Circuit Failure GEM GO to Pinpoint Test A . P1830 Transmission Transfer Case Counter Clockwise Shift Relay Coil Short Circuit to Battery GEM GO to Pinpoint Test A . P1832 Transmission Transfer Case Differential Lock-Up Solenoid Circuit Failure GEM GO to Pinpoint Test C . P1834 Transmission Transfer Case Differential Lock-Up Solenoid Short Circuit to Battery GEM GO to Pinpoint Test C . P1838 Transmission Transfer Case Shift Motor Circuit Failure GEM REFER to the Symptom Chart. P1846 Transmission Transfer Case Contact Plate 'A' Circuit Failure GEM REFER to the Symptom Chart. P1850 Transmission Transfer Case Contact Plate 'B' Circuit Failure GEM REFER to the Symptom Chart. P1854 Transmission Transfer Case Contact Plate 'C' Circuit Failure GEM REFER to the Symptom Chart. P1858 Transmission Transfer Case Contact Plate 'D' Circuit Failure GEM REFER to the Symptom Chart. P1866 Transmission Transfer Case System Concern - Servicing Required GEM REFER to the Symptom Chart. P1867 Transmission Transfer Case Contact Plate General Circuit Failure GEM REFER to the Symptom Chart. P1876 Transmission Transfer Case 2-Wheel Drive Solenoid Circuit Failure GEM GO to Pinpoint Test C . P1877 Transmission Transfer Case 2-Wheel Drive Solenoid Circuit Short to Battery GEM GO to Pinpoint Test C . P1891 Transmission Transfer Case Contact Plate Ground Return Open Circuit GEM REFER to the Symptom Chart.

Nov 26, 2017 | 2003 Ford F150 Regular Cab

1 Answer

99 ford f150 4wd won't engage, clicks but does not engage


Without knowing how the 4X4 works you don't have much chance of finding the problem , (tapping on stuff ) ? There is an electronic control module that makes this system work . Could have DTC'S - diagnostic trouble code's stored in the (GEM)
Transfer Case -Electronic Shift on the Fly (ESOF) Operation The electronic shift on the fly (ESOF) system is an electronic shift 4x4 system that allows the operator to choose between two different 4x4 modes as well as 2-wheel drive. The operator can switch between 2WD and 4H mode at speeds up to 88 km/h (55 mph). To engage or disengage 4L range, the vehicle speed must be less than 5 km/h (3 mph), the brake pedal depressed, and the transmission must be in NEUTRAL.
The transfer case is equipped with an electromagnetic clutch which is located inside the case. This clutch is used to spin up the front driveline when shifting from 2WD to 4H mode at speed. When the control switch on the instrument panel is turned, the generic electronic module (GEM) recognizes that a shift has been requested and activates the electromagnetic clutch and the relays which power the transfer case shift motor. When the shift motor reaches the desired position, as determined by the contact plate position inputs to the GEM, power to the shift relays and motors will be removed. When the transfer case front and rear output shafts are synchronized, the spring loaded lockup collar mechanically engages the mainshaft hub to the drive sprocket. Finally, the front axle collar is engaged and the electromagnetic clutch is deactivated.
Shifts between 2WD and 4H can be made at any speed up to 88 km/h (55 mph). Listed below are the inputs and outputs needed by the GEM to execute a change between any of these modes.
Feature Inputs:
  • 4WD mode switch (various resistances; go to Table 1).
  • Contact plate position inputs A, B, C, D (grounded when closed, open circuit when open; go to Table 4).
Feature Outputs:
  • 4x4 shift motor relay outputs (go to Table 2).
  • Transfer case clutch relay (grounded when relay is activated, open circuit when relay is deactivated).
  • 4x2/4x4 vacuum solenoid (grounded when activated, open circuit when deactivated).
  • Cluster indicators (ground when activated, open circuit when deactivated).
When shifting into or out of 4L, the GEM requires that the vehicle speed be less than 5 km/h (3 mph), the brake is applied, and the transmission is in NEUTRAL.

Feature Inputs:
  • 4WD Mode Switch (various resistances; go to Table 1).
  • Contact Plate Position Inputs A, B, C, D (grounded when closed, open circuit when open; go to Table 4).
  • Output Speed Shaft (OSS) Sensor (Sinusoid Signal: 0.7V-20V, 2.2 Hz/mph).
  • Brake Input (battery voltage when brake is depressed, open circuit when not activated).
  • Transmission Range Sensor (grounded when transmission is in NEUTRAL, open circuit otherwise).
  • Start/Clutch Depressed Input (go to Table 3).
Feature Outputs:
  • 4x4 Shift Motor Relay Outputs (go to Table 2).
  • 4x2/4x4 Vacuum Solenoid (grounded when activated, open circuit when deactivated).
  • Cluster Indicators (grounded when activated, open circuit when deactivated).
  • P1804 Transmission 4-Wheel Drive High Indicator Circuit Failure GEM REFER to Section 413-01A . P1806 Transmission 4-Wheel Drive High Indicator Short Circuit to Battery GEM REFER to Section 413-01A . P1812 Transmission 4-Wheel Drive Mode Select Circuit Failure GEM REFER to the Symptom Chart. P1815 Transmission 4-Wheel Drive Mode Select Short Circuit to Ground GEM REFER to the Symptom Chart. P1820 Transmission Transfer Case Clockwise Shift Relay Coil Circuit Failure GEM GO to Pinpoint Test A . P1822 Transmission Transfer Case Clockwise Shift Relay Coil Short Circuit to Battery GEM GO to Pinpoint Test A . P1824 Transmission 4-Wheel Drive Clutch Relay Circuit Failure GEM GO to Pinpoint Test E . P1826 Transmission 4-Wheel Drive Low Clutch Relay Short Circuit to Battery GEM GO to Pinpoint Test E . P1828 Transmission Transfer Case Counter Clockwise Shift Relay Coil Circuit Failure GEM GO to Pinpoint Test A . P1830 Transmission Transfer Case Counter Clockwise Shift Relay Coil Short Circuit to Battery GEM GO to Pinpoint Test A . P1832 Transmission Transfer Case Differential Lock-Up Solenoid Circuit Failure GEM GO to Pinpoint Test C . P1834 Transmission Transfer Case Differential Lock-Up Solenoid Short Circuit to Battery GEM GO to Pinpoint Test C . P1838 Transmission Transfer Case Shift Motor Circuit Failure GEM REFER to the Symptom Chart. P1846 Transmission Transfer Case Contact Plate 'A' Circuit Failure GEM REFER to the Symptom Chart. P1850 Transmission Transfer Case Contact Plate 'B' Circuit Failure GEM REFER to the Symptom Chart. P1854 Transmission Transfer Case Contact Plate 'C' Circuit Failure GEM REFER to the Symptom Chart. P1858 Transmission Transfer Case Contact Plate 'D' Circuit Failure GEM REFER to the Symptom Chart. P1866 Transmission Transfer Case System Concern - Servicing Required GEM REFER to the Symptom Chart. P1867 Transmission Transfer Case Contact Plate General Circuit Failure GEM REFER to the Symptom Chart. P1876 Transmission Transfer Case 2-Wheel Drive Solenoid Circuit Failure GEM GO to Pinpoint Test C . P1877 Transmission Transfer Case 2-Wheel Drive Solenoid Circuit Short to Battery GEM GO to Pinpoint Test C . P1891 Transmission Transfer Case Contact Plate Ground Return Open Circuit GEM REFER to the Symptom Chart. Your best bet , take it to a qualified repair shop. Tapping on thing's isn't the way to diagnose

Jan 10, 2018 | Cars & Trucks

1 Answer

I have a 1998 Chevy Blazer 4dr. The 4 whl drive switch does not light up. Some how the 4 whl drive got ingaged and now it is stuck there. I have a new switch on order but this is getting ridiculous. When...


The New Venture Gear Model NV233 is an electronically controlled optional transfer case for use on four wheel drive T trucks. The driver selects 2HI, 4HI, or 4LO by pushing one of three illuminating shift select buttons mounted on the instrument panel. The shift select buttons display the transfer case mode and range, self-test, diagnostic trouble codes, and electronic shift mechanical engaging problems.
During normal driving the transfer case is in the 2HI mode. When the transfer case is in the 2HI mode. When the transfer case is in 2HI both the 4HI and 4LO switch circuits are open, and both lights are OFF. When the four-wheel drive shift select button has been pressed, the four-wheel drive indicator lamp under the sift select button turns ON when the front axle has engaged. The shift select button will blink while the front axle is engaging. This is a normal condition.
The shifting of the transfer case is performed by a motor/encoder that receives drive signals from the transfer case control module (TCCM). When the driver selects one of the transfer case shift select buttons, request signals are sent to the TCCM. If the correct input signals exists, the TCCM will send drive voltages to the motor/encoder. The motor/encoder will position the transfer case to the ordered shift position.

Transfer Case Control Module Description
The TCCM performs the following functions:
• Receives input signals
• Processes the signal information
• Develops output signals
• Sends the output signal in order to control the shifting of the transfer case
The TCCM receives input signals from the following sources:
• The transfer case shift select buttons
• The NSBU switch on the vehicles with automatic transmissions
• The clutch position switch on the vehicles with manual transmissions
• The vehicle sped sensor calibrator module
• The encoder/motor range and the mode feedback signals
• The diagnostic enable
• The front axle mechanical status signal
In order to ensure the electronic shift system is operating properly, the transfer case control module (TCCM) continually performs diagnostics checks on itself and other parts of the electronic shift system when the ignition switch is in the run position. The following are different types of system checks that the TCCM continually performs.
Data Memory Retention Check
The TCCM checks the stored diagnostic trouble code memory to see if the memory has changed since the ignition switch was last positioned to OFF. This self test checks in order to see if the RAM standby power supply has been interrupted. If the TCCM detects a RAM standby power supply interruption, (the loss of stored diagnostic trouble code) the TCCM stores a DTC of 1 indicating RAM standby power failure.
This condition occurs when the TCCM is disconnected from the wiring harness or battery power is removed. The DTC of 1 automatically clears from the TCCM after cycling the ignition switch ON and OFF five times.

Before replacing parts you should test the system !
Diagnostic Trouble Code (DTC) Displaying
The transfer case shift control module is equipped with the ability to store diagnostic information, which is useful to a technician in the event of module, component or wiring failures. This information can be retrieved from the transfer case shift control module by way of flash codes, which are displayed on the three transfer case shift control switch buttons. These buttons are located on the instrument panel to the right of the steering wheel Before obtaining DTCs, perform the following transfer case control module (TCCM) Self-Test.
TCCM Self-Test
Observe the transfer case shift control switch indicators while turning the ignition switch to RUN. A properly operating system will flash all indicators and then will return to the current gear. If the system is operating normally, then proceed to Displaying Codes.
If the TCCM failed the Self-Test, then test the following circuits.
• Battery Positive Voltage (40 and 1640), and Ignition 3 Voltage for battery voltage
• Ground Circuit for ground
• Diagnostic enable circuit for an open or high resistance
• Transfer case shift control switch connector
If the above circuits are normal but the TCCM still fails the Self-Test, replace the TCCM. Refer to Transfer Case Shift Control Module Replacement .
DTC Displaying
Turn OFF the ignition for 10 seconds.
Connect PIN 13 on the data link cable (DLC) to a ground. The DLC is located in the cab under the instrument panel on the driver's side.
Turn ON the ignition, with the engine OFF.
Observe the transfer case shift control switch select buttons for flashing codes. Refer to Diagnostic Trouble Code (DTC) List .
Important: If the transfer case shift control switch buttons all blink only once and then stop, no fault codes are stored in the transfer case shift control module.
• When one DTC is stored in memory, that code will blink that number of times followed by a 3 second pause and then repeat.
• If more than one code is stored, the first code will blink, followed by a 3 second pause and then the second code will blink.
• This sequence will continue until PIN 13 on the DLC is no longer grounded.
• If the TCCM will not communicate the presence or absence of DTCs, test the above circuits in Self-Test Step 2. If the circuits are complete, then replace the TCCM. Refer to Transfer Case Shift Control Module Replacement .

Is the 4WD fuse # 15 -10 amp located in the I/P fuse box good ?

Jul 30, 2017 | 1998 Chevrolet Blazer

1 Answer

I have a 97 Chevy blazer with push button 4 wheel drive and it don't shift In to 4 low or 4 hi and the light should flash for 30 second then go back to 2 hi if it can't shift but when you push the button...


How about to the switch , is there battery power ? Fuse #15 FWD 10amp. I/P fuse panel . BCM - body control module light's the switch indicators 2hi, 4hi,4low . Check fuse #6 10amp I/P fuse panel .
DTC 002
The transfer case encoder motor is an assembly which houses four separate channels. These channels are used to indicate to the transfer case shift control module the present gear position of the transfer case or if the transfer case is in transition between gears. The encoder motor assembly consists of an electronically conductive inner ground ring in contact with a three legged wiper arm. Each leg's length is such that it makes contact with the conductive regions of the four channels. When any leg of the wiper arm is making contact with the conductive area of any channel, the encoder provides a path to ground to the inner ground ring.
During electronic shifting, the transfer case shift control module monitors the transfer case encoder circuit for the proper operating sequence. If at any time during a shift, the encoder changes from one position to any position other than the next possible position, an error counter in the transfer case shift control module increments by four. After the counter reaches 32, the transfer case shift control module set a DTC 2, a permanent "encoder fault," and reverts to a 2HI to 4LO or a 4LO to 2HI shift pattern only. To guard against a transient, random encoder fault due to vibration, dirt, electrical noise, etc., the fault counter reduces by one each time the transfer case shift control module detects a valid encoder value. The encoder must intermittently fail 25 percent of the time for the transfer case shift control module to consider it faulty and store DTC 2.

Test Description
The numbers below refer to the step numbers on the diagnostic table.
This step measures the voltage between the transfer case encoder circuit channels P, A, B, and C to ground.
This step tests the suspect circuit(s) for an open, short to power, or short to ground.
This step tests the encoder signal ground circuit for an open or high resistance.
DTC 2 -- Encoder Fault Step
Action
Value(s)
Yes
No
Schematic Reference: Transfer Case Control Schematics
1
Important: Check the transfer case shift control module for DTCs. The transfer case shift control module is not a class 2 device. DTCs are displayed on the transfer case shift control switch. Use the following four steps to obtain DTCs.
Turn OFF the ignition for 10 seconds.
Connect PIN 13 on the data link cable (DLC) to a ground. The DLC is located in the cab under the instrument panel on the driver's side.
Turn ON the ignition, with the engine OFF.
Observe the transfer case shift control switch select buttons for flashing codes.
Did you perform the Diagnostic System Check - Transfer Case?
--
YES - Go to Step 2
NO - Go to Diagnostic System Check
2
Disconnect the connector at the encoder motor.
Turn ON the ignition, with the engine OFF.
Measure the voltage between the transfer case encoder circuit channels P, A, B, and C to ground.
Does the voltage measure near the specified value?
4.8-5.1 V
YES - Go to Step 4
NO --Go to Step 3
3
Test the suspect circuit for an open, short to power, or short to ground. Refer to General Electrical Diagnosis and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
--
YES - Go to Step 8
NO - Go to Step 7
4
Turn the ignition switch OFF.
Test the encoder signal ground circuit for an open or high resistance. Refer to General Electrical Diagnosis and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
--
YES - Go to Step 8
NO - Go to Step 5
5
With a DMM at the transfer case module connector probe the encoder sign ground pin and ensure a good ground path through the module.
Did the DMM indicate a good ground path?
--
YES - Go to Step 6
NO - Go to Step 7
6
Replace the transfer case encoder motor. Refer to Motor/Encoder Replacement .
YES - Did you complete the replacement?
--
NO - Go to Step 8
--
7
Replace the transfer case shift control module. Refer to Transfer Case Shift Control Module Replacement .
YES - Did you complete the replacement?
--
NO - Go to Step 8
--
8
Clear all DTCs from memory. Refer to Diagnostic Trouble Code (DTC) Clearing .
Operate the vehicle while pressing each of the buttons on the transfer case shift control switch.
Does the DTC reset?
--
YES - Go to Step 2
NO - System OK

Aug 29, 2017 | 1997 Chevrolet Blazer

1 Answer

2002 gmc 2500 4wd truck


This DTC detects a short to voltage in the Motor Control A or Motor Control B circuits, or a shorted motor.
The transfer case motor is a bi-directional, permanent magnet, D.C. motor. When energized, (through Motor Control A or Motor Control B, the ground is provided by the opposing Motor Control circuit and then grounded through the transfer case shift control module ground circuit), the motor, through a series of gears, rotates a shaft which moves the mode and range forks to shift the transfer case between 4H, AUTO 4WD, 2H, N, and 4L ranges. While the transfer case motor is energized the transfer case shift control module also energizes the solenoid for the transfer case lock. The motor lock is disabled (locking action released) and free turning of the transfer case motor and sector shaft is then allowed.

Conditions for Setting the DTC
• The system will test the motor circuits by reading the voltage on each circuit.
• If the system detects a problem with the circuits, the DTC is logged.
• The transfer case shift control module senses a high voltage in the Motor Control A or Motor Control B circuits when a low voltage is expected.
Action Taken When the DTC Sets
• All shifting will be disabled.
• The SERVICE 4WD indicator will be latched on for the remainder of the current ignition cycle.
Conditions for Clearing the DTC
• The transfer case shift control module will clear the DTC if the condition for setting the DTC no longer exists.
• A history DTC will clear after 100 consecutive ignition cycles without a fault present.
• History DTCs can be cleared using a scan tool.

Schematic Reference: Transfer Case Control Schematics
1
Was the Transfer Case Diagnostic System Check performed?
--
Go to Step 2
Go to Diagnostic System Check - Transfer Case
2
Check the transfer Case shift control module for faulty power or grounds. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Was the condition found and corrected?
--
Go to Step 9
Go to Step 3
3
Install a scan tool.
Turn ON the ignition, with the engine OFF.
With the scan tool, command the Motor A/B control ON and OFF.
Does the encoder motor turn ON and OFF?
--
Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems
Go to Step 4
4
Turn the ignition OFF.
Disconnect the four wire connector at the transfer case.
Turn the ignition ON, with the engine OFF.
Connect a DMM between the Motor Control A circuit harness connector and ground at the transfer case.
Is the voltage reading within the specified value?
0-0.2 V
Go to Step 5
Go to Step 6
5
Connect a DMM between the Motor Control B circuit harness connector and ground at the transfer case.
Is the voltage reading within the specified value?
0-0.2 V
Go to Step 8
Go to Step 7
6
Disconnect the transfer case shift control module.
Test the Motor Control A circuit harness connector for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Was the condition found and corrected?
--
Go to Step 9
Go to Step 8
7
Disconnect the transfer case shift control module.
Test the Motor Control B circuit harness connector for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Was the condition found and corrected?
--
Go to Step 9
Go to Step 8
8
Replace the transfer case shift control module. Refer to Transfer Case Shift Control Module Replacement .
Is the repair complete?
--
Go to Step 9
--
9
Use the scan tool in order to clear the DTCs.
Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.
Does the DTC reset?
--
Go to Step 2
System OK

Jun 16, 2017 | 2002 GMC Sierra

Not finding what you are looking for?
1998 Lincoln Navigator Logo

Related Topics:

438 people viewed this question

Ask a Question

Usually answered in minutes!

Top Lincoln Experts

yadayada
yadayada

Level 3 Expert

78238 Answers

fordexpert

Level 3 Expert

5653 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22326 Answers

Are you a Lincoln Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...