Question about 1989 GMC K3500

1 Answer

Does the ECM control the automatic transmission or the shifting pattern?

Replaced ecm but still backfiring, popping, jerking and dying. Idles fine but will not run normally.

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  • GMC Master
  • 450 Answers

Probably not the ecm.. look for bad plug wires, vacuum leaks, timing settings, Crank Position sensor, Spark plug wires incorrectly installed, Try this.. Open the hood at night and look for the plug wires leaking.. you are looking for sparks.. I would look for disconnected Vac. hoses, broken or cracked vac hoses, ..

Posted on May 16, 2014

6 Suggested Answers

6ya6ya
  • 2 Answers

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Posted on Jan 02, 2017

centralvalle
  • 386 Answers

SOURCE: ecm fuse keeps blowing

just fixed this problem, change your fuel pump module, fuel sending unit shorts out on fuel level swing arm blue wire... unfortinately you must replace it as unit because of the design, fuel pump and tank guage fuel level sending unit are a one peice item, fuel tank has to come out to change unit, about a $ 700.00 repair too... fuel pump module runs about 350 to 700 $ depending on aftermarket or factory, try to find one with a lifetime warranty even if it is $ 50.00 more worth it..labor is about $ 250 to $ 400 depending on shop labor rate... definate problem though I ahve no doubt, common problem on GM... please rate my help, thanks...

Posted on Aug 06, 2009

  • 58 Answers

SOURCE: ECM BATT fuse keeps blowing

That fuse provides power for the fuel pump. Either your fuel pump is blowing the fuse or there is a shorted wire.

Posted on Dec 21, 2008

dmfixit
  • 226 Answers

SOURCE: ecm 2 location 1996 gmc 1500 sierra

http://www.autozone.com/shopping/locsSelect.htm
engine control computer

Posted on Jan 06, 2009

SOURCE: Automatic transmission shifts at higher than

It is slipping and about time for a rebuild
I would guess it is not the first trans in there after 20 years

Posted on Nov 25, 2010

Transdoc
  • 829 Answers

SOURCE: 1994 GMC 1500 Sierra has to rev up 1st gear and

If reverse is ok then you have a bad shift solenoid b.There are two solenoids on the back of the valve body that are identical,it will be the one on the pasenger side.GM calls them the 1-2 and 2-3 shift solenoid but this is deceptive because it takes a combination of them being on or off to achieve every gear.Pull the pan, disconnect solenoids and check resistance across them with a volt meter.I think you are looking for less than 20 ohms but the bad one will be off the chart.Bad transmission controllers are very rare in a GM vehicle.I bet if you have codes pulled you will find a shift solenoid code.Good luck!

Posted on Feb 21, 2011

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Shifter is locked in park on a 2002 bravada that sayes on dash its in reverse


PRND321 Display
The instrument panel cluster (IPC) displays the selected gear position as determined by the engine control module (ECM). The IPC - instrument panel cluster receives a serial data message from the ECM indicating the gear position. The PRND321 display blanks if:
?€¢
The ECM detects a malfunction in the transmission range switch circuit.


?€¢
The IPC detects a loss of serial data communications with the ECM. The automatic transmission shift lock control system is a safety device that prevents an inadvertent shift out of PARK when the engine is running. The driver must press the brake pedal before moving the shift lever out of the PARK position. The system consists of the following components:
?€¢
The automatic transmission shift lock control solenoid


?€¢
The automatic transmission shift lock control switch

With the ignition in the ON position, voltage is supplied to automatic transmission shift lock control switch. Voltage flows through the normally closed contacts of the automatic transmission shift lock control switch to the automatic transmission shift lock control solenoid. The automatic transmission shift lock control solenoid is permanently grounded. This energizes the automatic transmission shift lock control solenoid causing the transmission shift lever to be physically locked in the PARK position. When the brake pedal is pressed the contacts in the automatic transmission shift lock control switch open, de-energizing the automatic transmission shift lock control solenoid. This allows the shift lever to be move out of the PARK position.
The transmission range (TR) switch is part of the park/neutral position (PNP) and backup lamp switch assembly, which is externally mounted on the transmission manual shaft. The TR switch contains four internal switches that indicate the transmission gear range selector lever position. The PCM supplies ignition voltage to each switch circuit. As the gear range selector lever is moved, the state of each switch may change, causing the circuit to open or close. An open circuit or switch indicates a high voltage signal. A closed circuit or switch indicates a low voltage signal. The PCM detects the selected gear range by deciphering the combination of the voltage signals. The PCM compares the actual voltage combination of the switch signals to a TR switch combination chart stored in memory.
You need a Tech2 scan tool to diagnose this problem ! possible range sensor !

Sep 03, 2015 | Cars & Trucks

1 Answer

My 2004 buick rainer is stuck in park but dash board says its in drive how can i fix this


Automatic Transmission Shift Lock Control System
The automatic transmission shift lock control system is a safety device that prevents an inadvertent shift out of PARK when the engine is running. The driver must press the brake pedal before moving the shift lever out of the PARK position. The system consists of the following components:
?€¢
The automatic transmission shift lock control solenoid


?€¢
The automatic transmission shift lock control switch
Can you or can you not take it out of park ?
Shift Lever Does Not Move with Brake Pedal Depressed
yes or no ?
PRND321 Display
The instrument panel cluster (IPC) displays the selected gear position as determined by the engine control module (ECM). The IPC receives a serial data message from the ECM indicating the gear position. The PRND321 display blanks if:
?€¢
The ECM detects a malfunction in the transmission range switch circuit.


?€¢
The IPC detects a loss of serial data communications with the ECM.


You have a transmission range sensor or PCM problem , Need a professional grade scan tool to diagnose the problem , well that would be the easiest way to test .You should have all modules test for DTC'S - diagnostic trouble codes ! That would point you in the right direction ! I would suggest you google class 2 serial data communication network !

Aug 17, 2015 | Buick Cars & Trucks

1 Answer

TCC Release Swith needs to be fix. How do I do it?


Check your bake lights. If they don\'t come on, replace the brake switch (located on the brake pedal arm, under the dash) This is what controls the TCC solenoid off control. The jerk you feel is the transmission downshifting from overdrive to 4th or 3rd, depending on your transmission. If the lights come on, then you need to trace wires to the transmission to the brake switch or ECM.

Apr 06, 2014 | 1996 Chevrolet Cavalier

1 Answer

Dtc 0700 jerks when shifting from reverse to drive


The transaxle Control Module (TCM) monitors the malfunction of sensors and actuators relating to transaxle control. When the TCM detects a malfunction with the control, a signal is send to the Engine Control Module (ECM) to trigger the Engine Light or Service Engine Soon light. The ECM stores the P0700 code and it means the TCM detected a malfunction with the transaxle controls.
Read more: http://engine-codes.com/p0700_dodge.html#ixzz3Pn5lTBcI

Mar 30, 2014 | 2005 Dodge Grand Caravan

1 Answer

My 2008 Colorado cannot shift out park gear.I drove home in 4wd on Monday through snow and slush and parked. On Tuesday morning I couldn't get it out of park. I hefted on the shifter for quite a while and...


It may or may not be a problem with shifter interlock system .
Automatic Transmission Shift Lock Control System
The automatic transmission shift lock control system is a safety device that prevents an inadvertent shift out of PARK when the engine is running. The driver must press the brake pedal before moving the shift lever out of the PARK position. The system consists of the following components:
• The automatic transmission shift lock control solenoid
• The body control module (BCM)
• The engine control module (ECM)
• The transmission control module (TCM)
The body control module (BCM) controls the voltage supply circuit of the shift lock control solenoid. The following conditions must be met before the BCM will supply battery voltage to the shift lock control solenoid:
• The ignition is in the ON position.
• The ECM sends a serial data message to the BCM indicating the transmission is in the PARK position.
• The ECM receives a brake applied input from the brake light switch and sends a serial data message to the BCM indicating the brakes are not applied.
With the above conditions met, the BCM supplies battery voltage to the shift lock control solenoid. The solenoid is permanently grounded and therefore energizes, locking the shift lever in the PARK position. When the brake pedal is depressed the ECM send a serial data message to the BCM indicating the brakes are applied. The BCM turns off the battery voltage supply to the shift lock control solenoid. This de-energizes the shift lock control solenoid releasing the mechanical lock, allowing the driver to move the shift lever out of the PARK position. With the shift lever out of the PARK position the ECM sends a serial data message to the BCM and no voltage is applied to the shift lock control solenoid.

Apr 20, 2017 | Cars & Trucks

1 Answer

What does diagnostic code PO0706 and PO700 mean?


OBD II Fault Code
  • OBD II P0706
Fault Code Definition
  • Transmission Range Sensor Circuit Range/Performance
The purpose of the automatic transmission is to match the engine's optimum power and torque characteristics to the driver's desired rate of acceleration and speed by auto-selecting different gear ratios or 'speeds' to power the wheels. The Transmission Range Sensor (also referred to as the PRNDL input and/or neutral safety switch) tells the transmission control module (TCM) and the powertrain control module (PCM) that the transmission is in park, reverse, neutral, drive, low, 2nd, 3rd etc. It is attached directly to the manual valve of transmission, so when the shift lever is moved say from park to drive, the Transmission Range Sensor communicates this critical information to the above mentioned vehicle computer systems.

P0700
Many vehicles have a control module for the automatic transmission called a transmission control module (TCM). The engine control module (ECM) communicates with the TCM to monitor the automatic transmission for faults. If the TCM detects a fault in the automatic transmission and sets a transmission related fault code, the ECM is informed of this also and sets a P0700 in the ECM memory.

May 18, 2013 | 2000 Honda Civic

1 Answer

I have a suzuki jimny 2002 and get check engine light on and code P1600 an P0763 and when the switch is on i hear the relay on the TCM. can you suggest?


P0763 - Shift Solenoid C Electrical
Possible causes- Faulty shift solenoid C valve
- Shift solenoid C valve harness or connectors
- Shift solenoid C valve circuit is open or shorted
- Low transmission fluid level
- Dirty transmission fluid
When is the code detected?The P0763 code is detected when the gear required by the ECM does not match the actual gear when vehicle is driven.Symptoms- Engine Light ON (or Service Engine Soon Warning Light)
- Transmission will not shift gears.P0763 Description Shift solenoid valve C is turned ON or OFF by the Transmission Control Module (TCM) in response to signals sent from the park/neutral position (PNP) switch, vehicle speed and Engine Control Module (ECM) (throttle opening). Gears will then be shifted to the optimum position.

P1600 - Loss of KAM (Keep Alive ECM memory) Power; Open Circuit

Check all fuses related to the ECM

Jun 22, 2012 | Suzuki Jimny Cars & Trucks

2 Answers

2002 Rav-4 jerking shifting sometimes, what does the solenoid do?


My mom just had her 03 Rav4 begin the same problems. We took it to one of the best mechanics that we know. He told us for a brand new ECM would cost $1200. Now if the car is still under warrenty...which I don't think yours is anymore, it could cost only about $550. It also maybe a good idea to look at Rav4's of the same year that may have been in an accident or something, and see if you can have that ECM salvaged. I would also like to mention that the guy above says that they can't be reprogramed...they can be, its just recommended that you don't because then basically it would breach the conditions of the warrrenty. Also, there was a warning sent to Toyota when this problem arose, but it was never put out as a recall therefore no one knew about it until it began to happen...I hope this helps you. It helped my mom out, I wish you the best of luck.

Feb 21, 2010 | 2002 Toyota RAV4

1 Answer

Lexus rx300 2002 hard shift between 1st and 2nd. Fluid and filter changed 3000mi ago, car has 93000mi


The 1999-2003 Lexus RX300 models have a common failure of the engine computer that causes the harsh shifting of the transmission. You need to get the computer (ECM - Engine Control Module) rebuilt or replaced before it causes permanent damage to the transmission. Even if the transmission is already ruined, the ECM will still need to be repaired. Most often, the transmission is fine though, and rebuilding the ECM will restore the smooth shifts that the Lexus should have. Circuit Board Medics can rebuild the ECM and reprogram it so that you only have to plug it back in when you get it back. See the link below:

http://circuitboardmedics.com/1999-2003-lexus-rx300-hard-transmission-shifting-ecm-ecu-computer-repair/

Jan 25, 2010 | 2002 Lexus RX 300

1 Answer

Transmission slippage


The ECM (or, Electronic Control Module) is covered by the factory warranty for 96 months, or 80,000 miles, whichever comes first. Have your dealer refer to Toyota technical service bulletin "TC002-06" for info proving this. The fix is to replace the ECM. If you are below the above parameters, the repair should be free.

Also, if you have ever had your transmission fluids changed, it is CRITICAL that you use a specific auto transmission fluid, Toyota type "T-IV". Any other fluid will cause you problems. Please feel free to respond if you have any other questions; and Thnaks for choosing FixYa!

Nov 07, 2008 | 2002 Toyota RAV4

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