. May need to reprogram module due to disconnect.
CAUTION: Prior to removal of the GEM, it is necessary to upload module configuration information to a diagnostic tool. This information needs to be downloaded into the new module once installed. For additional information, refer to Section 418-01.
The following is list of GEM/CTM-controlled functions:
- wipers/washers (front/rear)
- warning chimes
- battery saver
- illuminated entry and courtesy lamps
- accessory delay
- driver power window (GEM only)
The GEM constantly monitors its subsystems for concerns. If a concern is found in one of the subsystems, the GEM will record the concern in the form of a diagnostic trouble code (DTC). The ignition switch position is very important to the GEM function. Often times, erratic or unexpected GEM function can be traced to concerns with ignition switch inputs.
Principles of Operation:
The generic electronic module (GEM) controls the opening of the driver window by activating the one-touch down window relay.
The GEM controls manual down and auto down window movement with the down window relay. The relay is activated by applying ground directly to one side of the down window relay coil, and deactivated by removing the ground signal. The delayed accessory relay provides power for the operation of the power windows and the roof opening panel (if equipped). The delayed accessory feature is active when the ignition switch is in the RUN or the ACC position, or when the ignition switch is changed from RUN or ACC to the OFF/LOCK position and the driver and passenger doors are closed.
Down window motion operates in two modes, manual mode and auto mode. When the GEM detects the first down position, first detent on the switch, it enters manual mode. In manual mode, the window will move downward only while the switch is depressed. Similarly, when the GEM detects the second down position, second detent on the switch, it enters auto mode. In auto mode, the window will open completely with just a momentary press of the switch.
the GEM will activate the one-touch down window relay until one of the following conditions is met:
- The driver window control switch is pushed to the UP position.
- The driver window control switch is released (OFF position) and then moved to the down position (first detent) or the one-touch down position (second detent).
- Seven seconds have elapsed since the one-touch down feature was initiated.
- A window regulator motor stall condition is detected on the one-touch down sense line inputs.
The GEM will deactivate the delayed accessory feature when:
Inspection and Verification
- the driver/passenger door is ajar and the ignition switch is in the OFF/LOCK or KEY-OUT position.
- 10 minutes have elapsed since the ignition switch was changed from ACC or RUN to the OFF/LOCK position.
- Verify the customer concern by operating the system.
- Visually inspect for obvious signs of mechanical or electrical damage.
Visual Inspection Chart
- Window regulator motor
- Window glass
- Central junction box (CJB) Fuse:
- 6 (5A)
- 8 (5A)
- 15 (5A)
- 17 (10A)
- 18 (5A)
- 20 (5A)
- Battery junction box (BJB) Fuse:
- 103 (50A)
- 110 (30A)
- 116 (40A)
- 601 (30A)
- Window control switch
- Window regulator motor
- Damaged wiring harness
- Loose or corroded connector(s)
- If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.
- If the scan tool does not power up:
- check that the program card is correctly installed.
- check the connections to the vehicle.
- check the ignition switch is in RUN position.
- If the scan tool still does not power up, refer to the scan tool manual.
- Carry out the DATA LINK DIAGNOSTICS test. If the scan tool responds with:
- CKT914, CKT915 or CKT70 = ALL ECUS NO RESP/NOT EQUIP, refer to Section 418-00.
- SYSTEM PASSED, retrieve and record the continuous diagnostic trouble codes (DTCs), erase the continuous DTCs, and carry out the self-test diagnostics for the GEM.
- If the DTCs retrieved are related to the concern, go to the GEM Diagnostic Trouble Code (DTC) Index to continue diagnostics.
- If no DTCs related to the concern are retrieved, proceed to the Symptom Chart to continue diagnostics.
- The one-touch down feature is inoperative
- Battery saver relay.
- One-touch down relay.
- Driver window control switch.
- Driver window regulator motor.
- Central junction box (CJB).
- Generic electronic module (GEM).