Tire sensor fault on information center and drivers door will not unlock with remote key fob

Time for a new key fob ? Does it work good for locking the doors ?
Module Controlled Functions The multifunction modules consist of the following:

• generic electronic module (GEM)/central timer module (CTM)
• remote anti-theft personality (RAP) module (15K602)

The remote anti-theft personality (RAP) module controls the keyless entry, and computer operated locks systems.
The GEM/CTM controls the following features:

• wiper/washer (front/rear)
• warning chime
• battery saver
• illuminated entry and courtesy lamps
• driver one touch down power window (GEM only)
• accessory delay
• 4 wheel drive (GEM only)
• For keyless entry concerns, refer to Section 501-14B .
• Keyless Entry The keyless entry system components consist of the following:
  
  • keyless entry remote transmitter (15K601)
  • remote anti-theft personality (RAP) module (15K602)
  • driver unlock relay (if equipped with two step unlocking)
  • all unlock relay
  • all lock relay
  • keyless entry keypad (14A626)
  The electronic door lock system has three main components: the remote anti-theft personality (RAP) module, attached to the rear left hand quarter panel, the three-button (hand held) keyless entry remote transmitter (15K601), and the keyless entry keypad (14A626) on the driver side door.
  The door locks are controlled by the RAP module through three external relays: the driver unlock relay (if equipped with two step unlocking), the all unlock relay, and the all lock relay. These relays are located in the relay box on the LH rear quarter panel.
  The keyless entry remote transmitter initiates the following electronic door lock system functions:
  
  • Unlocks the driver door (if equipped with two step unlocking).
  • Unlocks all doors.
  • Locks all doors.
  • Enables the panic alarm.
  • Issues the interior lamps on (when unlocking) and off (when locking) commands to the generic electronic module (GEM).
  • Sounds the horn (13832) once when LOCK on keyless entry remote transmitter is pressed twice, and doors are closed.
  • Sounds the horn twice when LOCK on the keyless entry remote transmitter is pressed twice, and any door or the liftgate window is ajar.
  • Allows up to four keyless entry remote transmitters to be programmed.
  • The order that the transmitters are programmed into the module will set the memory seat to the corresponding position when the driver door is unlocked with the transmitter.
  NOTE: The remote entry features will not function when the ignition switch (11572) is in the RUN or ACC position.
  The keyless entry remote transmitters are reprogrammable and must be set at the same time.
  To confirm that the doors have been locked and that the anti-theft system has armed, press the LOCK button again, within five seconds of the first press. The horn will sound once if the doors have locked and all doors are closed.
  
• Inspection and Verification
  
  1. Verify the customer concern by operating the electronic door lock control system.
  1. Visually inspect for obvious signs of mechanical and electrical damage; refer to the following chart:
     
     Visual Inspection Chart Mechanical Electrical
     • Binding latches
     • Fuse(s) 20 (7.5A), 9 (20A), 18 (10A), 1 (60A), and 25 (7.5A)
     • Relays
     • Wiring harness
     • Loose or corroded connections
     • Keyless entry keypad
     • Remote transmitter
     • Door open warning lamp switch
  1. If the concern remains after the inspection, connect the scan tool to the data link connector (DLC) located beneath the instrument panel and select the vehicle to be tested from the scan tool menu. If scan tool does not communicate with the vehicle:
     • check that the program card is properly installed.
     • check the connections to the vehicle.
     • check the ignition switch position.
  1. If scan tool still does not communicate with the vehicle, refer to the scan tool manual.
  1. Perform the DATA LINK DIAGNOSTIC TEST. If the scan tool responds with:
     • CKT914, CKT915 or CKT70 = ALL ECUS NO RESP/NOT EQUIP, refer to Section 418-00 .
     • NO RESP/NOT EQUIP for RAP, go to Pinpoint Test A.
     • NO RESP/NOT EQUIP for GEM/CTM, go to Pinpoint Test G.
     • SYSTEM PASSED, retrieve and record the continuous diagnostic trouble codes (DTCs), erase the continuous DTCs and perform self-test diagnostics for the RAP.
  1. If the DTCs retrieved are related to the concern, go to RAP Diagnostic Trouble Code (DTC) Index or GEM/CTM Diagnostic Trouble Code (DTC) Index to continue diagnostics.
  1. If no DTCs related to the concern are retrieved, proceed to Symptom Chart to continue diagnostics. Taking your vehicle to a qualified repair shop mite be your best bet , one that has a scanner that can read these code
  2. RAP Module Diagnostic Trouble Code (DTC) Index
     RAP Module Diagnostic Trouble Code (DTC) Index DTC Description DTC Caused By Action B1309 Power Door Lock Circuit Short to Ground RAP GO to Pinpoint Test C . B1341 Power Door Unlock Circuit Short to Ground RAP GO to Pinpoint Test C . B1485 Brake Pedal Input Circuit Short to Battery RAP GO to Pinpoint Test D . B1526 Keyless Entry Keypad Switch Circuit Short to Ground RAP GO to Pinpoint Test B . B1629 PRNDL Reverse Input Short to Battery RAP GO to Pinpoint Test E . B1845 Ignition Tamper Circuit Failure RAP Invalid DTC. Ignore this DTC. B2425 Keyless Entry Out of Synchronization RAP GO to Pinpoint Test C . B1334 Decklid Ajar Rear Door Circuit Short to Ground RAP REFER to Section 417-02 .

There are fuse's for the module that controls the keyless entry . If fuse's were the problem you would have a lot more problems then just keyless entry . Have you tried replacing the battery in the key fob. There are also relay's , door unlock an door lock relays , located in the central junction box . Under the dash some place . There are controlled by the GEM - genaric electronic module . Ford's BCM - body control module .

To find out what is draining the battery do a parasitic draw test . How To Perform Parasitic Draw Test EricTheCarGuy Test to be sure , before replacing GEM module .I would also have the GEM checked for DTC'S - diagnostic trouble codes . I would also check the battery saver relay .
SECTION 417-02: Interior Lighting 2000 Explorer/Mountaineer Workshop Manual DESCRIPTION AND OPERATION Procedure revision date: 06/17/1999 Interior Lighting The interior lighting system consists of the following:

• dome/map lamp
• rear dome/cargo lamp
• overhead console/map lamp
• RH/LH vanity mirror
• ash receptacle lamp
• puddle lamps
• interior lamp switches
• interior lamp relay
• dimmer module
• battery saver relay
• generic electronic module (GEM)

Generic Electronic Module (GEM)/Central Timer Module (CTM) Controlled Functions
The generic electronic module (GEM) is equipped on four-wheel drive vehicles with power windows. The central timer module (CTM) is equipped only on two-wheel drive vehicles without power windows.
NOTE: GEM/CTM diagnostics are compatible with the scan tool.
The GEM/CTM incorporates the functions of several different modules into one, and offers diagnostics to easily locate and repair concerns affecting the subsystems that it controls.
The GEM/CTM constantly monitors the systems it controls and reports a concern in the form of a diagnostic trouble code (DTC). A DTC can be retrieved with the scan tool through the communication link.
The scan tool is a menu-driven tester that allows the user to run specific tests. The scan tool can isolate faults in the GEM/CTM subsystems through a symptom-driven diagnostic procedure. Connecting the scan tool to the GEM/CTM communication link will not alert the GEM/CTM. If the GEM/CTM is "asleep" when the diagnostic connector is plugged in, the GEM/CTM must be "awakened". If the communication link cannot be established, turn the ignition to RUN.
NOTE: The GEM/CTM has a sleep function to minimize battery consumption. During the sleep mode, the GEM/CTM turns off all outputs and monitors only the following:

• door ajar (driver door, passenger door, liftgate, LH rear and RH rear doors).
• key-in-ignition.
• key in RUN or ACC.
• two-step unlock switch (unarm switch).
• digital TR sensor.
• illuminated entry request (remote anti-theft personality [RAP] module).

If a change of status occurs at one of these inputs while the GEM/CTM is "asleep", the GEM/CTM will "wake up." When the GEM/CTM awakens, it carries out an internal self-test, and begins normal operation. At this point, the GEM/CTM will have all of its functions operational.
The GEM/CTM will go into the sleep mode immediately after both of the following conditions have been met:

• key in OFF or key not in ignition.
• after 45 minutes with no change in any wake-up input.

The GEM/CTM control system has two modes of operation; the normal operating mode and the tester-dependent diagnostics mode.
Normal operation of the GEM/CTM can detect errors. An integral part of normal GEM/CTM operation is continuous diagnostic capability. Continuous diagnostics detects errors and changes the GEM/CTM control strategy. There is no warning lamp for the GEM/CTM; therefore, a DTC concern will direct you to the GEM/CTM. Examples of faults that may be detected during normal operation include:
NOTE: The GEM/CTM can only detect open circuit/short to GRD faults when the GEM/CTM is not energizing a load, and short to battery faults when the GEM/CTM is attempting to energize a load.

• GEM/CTM continuous self-test (RAM, ROM, EEPROM, A/D checking).
• output driver monitoring (open circuit/short to ground [GRD], short to power).

• illogical combinations of input signals.

No smart junction box , GEM - generic electronic module ! this module energizes the relays in the battery junction box ! The gem module is behind the center of the dash !
Generic Electronic Module (GEM) Removal and Installation

1. > CAUTION: Prior to removal of the generic electronic module (GEM), it is necessary to upload module configuration information to the diagnostic tool. This information needs to be downloaded into the new module once installed. For additional information, refer to Section 418-01 .
   Depower the supplemental restraint system (SRS). For additional information, refer to Section 501-20B .

1. Remove the radio chassis. For additional information, refer to Section 415-01 .

1. Remove the center instrument panel finish panel.
   1. Remove the screws.
   1. Remove the center instrument panel finish panel.
   • Disconnect electrical connectors.
   • Module Controlled Functions The multifunction modules consist of the following:
     
     • generic electronic module (GEM)
     • central security module
     The GEM controls the following features:
     
     • front wiper and washer
     • warning chime
     • battery saver
     • illuminated entry and interior lighting
     • driver one-touch down power window (optional)
     • battery saver relay
     • door ajar warning indicator lamp
     • safety belt warning indicator lamp
     The central security module controls the following features:
     
     • remote keyless entry
     • computer-operated lock system
     • trim switch unlock inhibit
     It's more then likely to have DTC'S diagnostic trouble codes stored in it's memory !
   • B1431 Wiper Brake/Run Relay Circuit Failure GEM REFER to Section 501-16 . B1432 Wiper Brake/Run Relay Circuit Short to Battery GEM REFER to Section 501-16 . B1434 Wiper Hi/Low Speed Relay Circuit Failure GEM REFER to Section 501-16 . B1436 Wiper Hi/Low Speed Relay Circuit Short to Battery GEM REFER to Section 501-16 . B1438 Wiper Mode Select Switch Circuit Failure GEM REFER to Section 501-16 . B1441 Wiper Mode Select Switch Circuit Short to Ground GEM REFER to Section 501-16 . B1446 Wiper Park Sense Circuit Failure GEM REFER to Section 501-16 . B1450 Wiper Wash/Delay Switch Circuit Failure GEM REFER to Section 501-16 . B1453 Wiper Wash/Delay Switch Circuit Short to Ground GEM REFER to Section 501-16 . B1458 Wiper Washer Pump Motor Relay Circuit Failure GEM REFER to Section 501-16 . B1460 Wiper Washer Pump Motor Relay Circuit Short to Battery GEM REFER to Section 501-16 . B1462 Safety Belt Switch Circuit Failure GEM REFER to Section 413-09 . B1466 Wiper Hi/Low Speed Not Switching GEM REFER to Section 501-16 . B1473 Wiper Low Speed Circuit Motor Failure GEM REFER to Section 501-16 . B1476 Wiper High Speed Circuit Motor Failure GEM REFER to Section 501-16 Your wipers do not work at all ? did you check this fuse Central Junction Box (CJB) fuse 16 (30A)
   • • The wipers are inoperative
     • Central junction box (CJB) fuse:
       • 16 (30A)
     • Circuitry.
     • GEM.
     • Multifunction switch.
     • Wiper run/park relay.
     • Wiper HI/LO relay.
     • Wiper motor.
     • GO to Pinpoint Test A .
     Before replacing parts you need to test , check for codes !

you just get this car.
or it worked before but not now? key questions.

door switch driver and RKE not working right.

and some cars the driver has a master switch and local switch.
and some have a kids safe switch that kills the other doors.
i dont have the opr,guides. for liberties.

in this case , this is a programmable feature. most newer jeeps.
you can program most cars. for (only driver door works with fob)
this is for security, (like airport parking , alone, at night)
the operators guide (lost already )covers this. in the glove box.
most folks don't read it ,they just drive to jeep service and
ask to have it set like you want. and pay $100.
it could be a fault too... but that will take checking above first.
on my other car, i must click 2 times to open all doors, (GM)

the dealer will scan the PCM/BCM puters. to see if they are throwing
DTC errors. any good scan tool can do this.
and check fuses first. never last. or get egg in face.

did you read this?
http://justgivemethedamnmanual.com/jeep/jeep-liberty-owners-manuals/

lost it , then get it and put it on a flash stick and put it back in the glove box or burn a CD . (or kill a tree and print it)

page 21
To Unlock the Doors and Liftgate
Press and release the UNLOCK button on the RKE
transmitter once to unlock the driver's door or twice to
unlock all doors and the liftgate. The turn signal lights
will flash to acknowledge the unlock signal. The illuminated
entry system will also turn on.

Remote Key Unlock, Driver Door/All Doors First
This feature lets you program the system to unlock either
the driver's door or all doors and the liftgate on the first
press of the UNLOCK button on the RKE transmitter. To
change the current setting, proceed as follows:
• For vehicles equipped with the Electronic Vehicle
Information Center (EVIC), refer to "Remote Key
Unlock," under "Personal Settings (Customer-
Programmable Features)," under "Electronic Vehicle
Information Center (EVIC)" in Section 4.
end quote.

my GUESS, you didnt RTM.
read it.

The keyless entry system is controlled by the (GEM) - generic electronic module .
Keyless Entry The electronic door lock system has two main components:

• generic electronic module (GEM)(14B204)
• keyless entry remote transmitter (15K601)
• NOTE: Battery power and ground must be remove before disconnecting the GEM connectors to avoid setting false codes.
  Power Locks Operation The power locks feature allows the customer to lock and unlock the doors via momentary switches located on the driver and passenger door. When the GEM detects a momentary press of the driver or passenger lock button, the GEM will supply power to the driver or passenger lock actuators for approximately 250 ms from relays internal to the GEM. When the GEM detects a momentary press of the driver or passenger unlock button, the GEM will supply power to the driver or passenger unlock actuators for approximately 250 ms from relays internal to the GEM.
  Remote Keyless Entry Door Locks Operation The remote entry feature allows the customer to unlock the driver door, unlock all doors, and lock all doors using a valid remote transmitter as long as the ignition switch is not in RUN or START. The driver door is unlocked whenever the GEM detects a valid remote transmitter unlock transmission. All the doors are unlocked when the GEM detects a second valid remote transmitter unlock transmission within three seconds of the first transmission. All the doors are locked when the GEM detects a valid remote transmitter lock transmission. If the GEM detects a second valid remote transmitter lock transmission within three seconds of the first transmission, the doors will lock again, the horn will sound for 20 ms and the parking lamps will flash for 200 ms to indicate the doors are locked. If the GEM detects the driver or passenger door is ajar during the second lock transmission, the doors are locked again and the horn is sounded twice. If the GEM detects a valid remote transmitter lock transmission within three seconds of detecting a valid remote transmitter unlock transmission, the GEM will lock all the doors
• • The doors do not lock/unlock using the remote transmitter
  • Ignition switch.
  • GEM.
  • Remote transmitter.
  • Remote transmitter batteries.
  • GO to Pinpoint Test C .
  You followed the program instructions to the letter ? Programming -Keyless Entry Remote Transmitter NOTE: All keyless entry remote transmitters (15K601) must be programmed at the same time.
  NOTE: All previous transmitter identification codes (TIC's) will be erased when programming mode is entered.
  NOTE: To program (or reprogram) the keyless entry remote transmitters into the generic electronic module (GEM)(14B204), perform the following steps.
  
  1. Turn the ignition from OFF to RUN eight times within 10 seconds, ending in RUN. If the GEM has successfully entered program mode, it will lock and unlock all the doors.
  1. NOTE: The first TIC must be entered within 7.5 seconds of entering the program mode and additional TICs must be entered within 7.5 seconds of the first TIC. The programming mode is exited whenever the timing constraints are not met.
     Press any button on a keyless entry remote transmitter, and the doors will lock and then unlock to confirm that each keyless entry remote transmitter has been programmed.
  1. If the door locks do not respond for any keyless entry remote transmitter, wait for several seconds and press the button again.
  1. Turn the ignition switch to the OFF position, or wait up to five minutes after step 1, to exit program mode. If a keyless entry remote transmitter has been programmed (or reprogrammed), the GEM will lock and unlock all the doors one last time.
  1. Take an have the vehicle checked for DTC'S

B1396 Power Door Lock Circuit Short to Battery GEM GO to Pinpoint Test B . B1397 Power Door Unlock Circuit Short to Battery GEM

It's hard to check the relay's for the door locks if you don't know where they are . They are not silver can type , they are one inch square ! They are located behine driver side rear quarter panel .
NOTE: The door ajar state will be monitored continuously for 500 ms after locking has occurred. If a door is opened again within 500 ms, the driver door will unlock
The electronic door lock system has three main components: the remote anti-theft personality (RAP) module, attached to the rear left hand quarter panel, the three-button (hand held) keyless entry remote transmitter (15K601), and the keyless entry keypad (14A626) on the driver side door.
The door locks are controlled by the RAP module through three external relays: the driver unlock relay (if equipped with two step unlocking), the all unlock relay, and the all lock relay. These relays are located in the relay box on the LH rear quarter panel.
The keyless entry remote transmitter initiates the following electronic door lock system functions:
Do you know what DTC'S - diagnostic trouble codes are ?
RAP Module Diagnostic Trouble Code (DTC) Index
RAP Module Diagnostic Trouble Code (DTC) Index DTC Description DTC Caused By Action B1309 Power Door Lock Circuit Short to Ground RAP GO to Pinpoint Test C . B1341 Power Door Unlock Circuit Short to Ground RAP GO to Pinpoint Test C . B1485 Brake Pedal Input Circuit Short to Battery RAP GO to Pinpoint Test D . B1526 Keyless Entry Keypad Switch Circuit Short to Ground RAP GO to Pinpoint Test B . B1629 PRNDL Reverse Input Short to Battery RAP GO to Pinpoint Test E . B1845 Ignition Tamper Circuit Failure RAP Invalid DTC. Ignore this DTC. B2425 Keyless Entry Out of Synchronization RAP GO to Pinpoint Test C . B1334 Decklid Ajar Rear Door Circuit Short to Ground RAP REFER to Section 417-02 . .Without seeing if any codes are stored could go in a wrong diagnostic direction . You don't want to change parts that are not needed .

1. Remove the LH rear quarter trim panel; refer to Section 501-05 .

1. Disconnect the two remote anti-theft personality (RAP) module electrical connectors.

Generic Electronic Module (GEM)/Central Timer Module (CTM) Controlled Functions
The generic electronic module (GEM) is equipped on four-wheel drive vehicles with power windows. The central timer module (CTM) is equipped only on two-wheel drive vehicles without power windows.
NOTE: GEM/CTM diagnostics are compatible with the scan tool.
The GEM/CTM incorporates the functions of several different modules into one, and offers diagnostics to easily locate and repair concerns affecting the subsystems that it controls.
The GEM/CTM constantly monitors the systems it controls and reports a concern in the form of a diagnostic trouble code (DTC). A DTC can be retrieved with the scan tool through the communication link.
The scan tool is a menu-driven tester that allows the user to run specific tests. The scan tool can isolate faults in the GEM/CTM subsystems through a symptom-driven diagnostic procedure. Connecting the scan tool to the GEM/CTM communication link will not alert the GEM/CTM. If the GEM/CTM is "asleep" when the diagnostic connector is plugged in, the GEM/CTM must be "awakened". If the communication link cannot be established, turn the ignition to RUN.
NOTE: The GEM/CTM has a sleep function to minimize battery consumption. During the sleep mode, the GEM/CTM turns off all outputs and monitors only the following:

• door ajar (driver door, passenger door, liftgate, LH rear and RH rear doors).
• key-in-ignition.
• key in RUN or ACC.
• two-step unlock switch (unarm switch).
• digital TR sensor.
• illuminated entry request (remote anti-theft personality [RAP] module).
• . There are more DTC'S for the GEM ,too many too post here . There is also a relay module behind the dash , looks like behind the radio , heater / A/C panel .

Do you know how to do automotive electrical testing using a wiring diagram an a DVOM - digital volt ohm meter ? How to test power an grounds ?

Electric Testing Techniques You Need to Know
You can view wiring diagrams here http://www.bbbind.com/free_tsb.html Enter vehicle info. year , make , model an engine size . Under system click body & accessories , sub system click power locks .Then click search , then click on the links one at a time . Watch this video ,

Door Locks Go Crazy 1 watch all three . This a dodge , doesn't matter , just want to show how to test .

I think you need to reprogram the module, you deleted the horn chirp and light flash confirmation. he dealer can reprogram for you.


Customer Preference Items NOTE: If using the WDS, select Module Configuration and Programming, then follow the screen prompts.
NOTE: Make sure module is listed as supporting customer preference items and supports the specific item to be configured in the Module Configuration Index in this section.

1. Select Service Bay Functions on the diagnostic tool.

1. Select the module that contains the customer preference item to be programmed. Refer to the Module Configuration Index in this section.

1. Select Customer Preference Items on the diagnostic tool.

1. Select Module Option Content.

1. Select the item to be enabled or disabled.

1. Enable or disable the item as necessary to reflect the customer preference.

------------------------------------------------------------------------

----------------------------------------------------------------------------
Principles of Operation
Power Door Locks
The generic electronic module (GEM) controls the power door lock and keyless entry system. Lock and unlock operation is achieved through the use of internal relays in the GEM. The relays are all door lock, all door unlock and driver door unlock. The normal path of the relays is to ground.
Pressing the door lock control switch to lock or unlock sends a ground signal to the GEM. The same GEM pin is used for unlock and lock input. The unlock signal is a direct connection to ground. The lock signal is altered by an internal resistor in the door lock control switch. This varied resistance identifies lock or unlock command to the GEM.
The door locks can also be controlled by the door key cylinder switches. For the liftgate door lock switch, turning the key to lock or unlock sends a ground signal to the GEM. The GEM will then ground the all door lock or all door unlock relay supplying voltage to the actuators. Turning the driver door key cylinder to the lock position sends a ground signal to the GEM. The GEM will then ground the all door lock relay supplying voltage to the actuators. Turning the driver door key cylinder to unlock sends a ground signal to GEM. The GEM will ground the driver door unlock relay and supply voltage to only the driver door actuator. If a second unlock ground is received within three seconds of the first, the GEM will ground the all door unlock relay supplying voltage to the passenger door actuators (if 2-stage unlock is equipped).
Keyless Entry
The keyless entry remote transmitter sends a signal that is received by the GEM internal antenna. Depending on the signal received, the GEM module will ground the appropriate internal relay and lock all doors or unlock the driver door. If the unlock signal is received again within three seconds of the first unlock, the GEM will ground the internal all door unlock relay unlocking all doors. The lock and unlock relay output to the actuators is controlled by the GEM, the same as power door lock operation from the control switch.
If the signal received is for the panic button, the GEM will cycle ground to the park lamp relay coil and horn relay coil. The park lamps and horn will continue to cycle until the panic button is pressed again or the ignition switch is turned to the RUN position, or after the timer expires.

This does not sound like a fob fault - but a locking control module fault , either in the hardware or software of the unit. Get it checked at a Jaguar dealers. When unlocking using the key - as soon as the door is opened you should hear a chime sounding inside the car - this is a timer counting down to sounding the alarm. If you put your key in the ignition as soon as you open the door the alarm should not go off and the chime should stop. If it does not this again points to a fault in the locking controller.
hope this helps - good luck.

I would suspect you have a bad door switch on one of the doors or liftgate. They are usually plunger switches. Try pusing them in one at a time and see f the lights go out. Hold it in long enough to account for the time delay.

please rate if this helps you.

---------

• The Courtesy Lamps Stay On Continuously

• Circuitry.
• GEM/CTM.
• Ignition switch.
• Interior lamp relay.
• Dimmer module.
• Door ajar switch.
• DTC B1322.
• DTC B1330.
• DTC B1334.
• DTC B1338.
• DTC B1371.
• DTC B1574.
• DTC B1610.

------------------------------------
Generic Electronic Module (GEM)/Central Timer Module (CTM) Controlled Functions
The generic electronic module (GEM) is equipped on four-wheel drive vehicles with power windows. The central timer module (CTM) is equipped only on two-wheel drive vehicles without power windows.
NOTE: GEM/CTM diagnostics are compatible with New Generation STAR (NGS) Tester.
The GEM/CTM incorporates the functions of several different modules into one, and offers diagnostics to easily locate and repair concerns affecting the subsystems that it controls.
The GEM/CTM constantly monitors the systems under its control and reports a concern in the form of a diagnostic trouble code (DTC). A DTC can be retrieved with NGS Tester through the communication link.
NGS Tester is a menu-driven tester that allows the user to run specific tests. NGS Tester can isolate faults in the GEM/CTM subsystems through a symptom-driven diagnostic procedure. Connecting NGS Tester to the GEM/CTM communication link will not alert the GEM/CTM. If the GEM/CTM is "asleep" when the diagnostic connector is plugged in, the GEM/CTM must be "awakened". If the communication link cannot be established, it is advised to turn the ignition to RUN.
NOTE: The GEM/CTM has a sleep function to minimize battery consumption. During the sleep mode, the GEM/CTM turns off all outputs and monitors only the following:

• Door ajar (driver door, passenger door, liftgate, LH rear and RH rear doors).
• Key-in-ignition.
• Key in RUN or ACC.
• Two-step unlock switch (unarm switch).
• Digital TR sensor.
• Illuminated entry request (remote anti-theft personality [RAP] module).

If a change of status occurs at one of these inputs while the GEM/CTM is asleep, the GEM/CTM will "wake up." When the GEM/CTM awakens, it performs an internal self-test, and begins normal operation. At this point, the GEM/CTM will have all of its functions operational.
The GEM/CTM will go into the sleep mode immediately after both of the following conditions have been met:

• Key in OFF or key not in ignition.
• After 45 minutes with no change in any wake-up input.

The GEM/CTM control system has two modes of operation; the normal operating mode and the tester-dependent diagnostics mode.
The normal operation of the GEM/CTM can detect errors. An integral part of the normal GEM/CTM operation is the continuous diagnostic capability. Continuous diagnostics detects errors and changes the GEM/CTM control strategy. There is no warning lamp for the GEM/CTM; therefore, a DTC concern will direct you to the GEM/CTM. Examples of faults that may be detected during normal operation include:
NOTE: The GEM/CTM can only detect open circuit/short to GRD faults when the GEM/CTM in not energizing a load, and short to battery faults when the GEM/CTM is attempting to energize a load.

• GEM/CTM continuous self-test (RAM, ROM, EEPROM, A/D checking).
• Output driver monitoring (open circuit/short to ground [GRD], short to power).

• Illogical combinations of input signals.