Grand Cherokee 4WD Laredo V8-4.7L (2002)
Seat Track: Testing and Inspection
Following are tests that will help to diagnose the hard wired components and circuits of the power seat system. However, if the vehicle is also equipped
with the optional memory system, these tests may not prove conclusive in the diagnosis of the driver side power seat. In order to obtain conclusive
testing of the driver side power seat with the memory system option, the Programmable Communications Interface (PCI) data bus network and all of the
electronic modules that provide inputs to, or receive outputs from the memory system components must be checked.
The most reliable, efficient, and accurate means to diagnose the driver side power seat with the memory system option requires the use of a DRB scan
tool and the proper Diagnostic Procedures. The DRB scan tool can provide confirmation that the PCI data bus is functional, that all of the electronic
modules are sending and receiving the proper messages on the PCI data bus, and that the memory system is receiving the proper hard wired inputs and
relaying the proper hard wired outputs to perform its driver side power seat functions.
Actuate the power seat switch to move all three power seat track adjusters in each direction. The power seat track adjusters should move in each of the
selected directions. If a power seat track adjuster fails to operate in only one direction, move the adjuster a short distance in the opposite direction and
test again to be certain that the adjuster is not at its travel limit. If the power seat track adjuster still fails to operate in only one direction, refer to Power
Seat Switch Diagnosis and Testing in this group. If the power seat track adjuster fails to operate in more than one direction, perform the following tests.
For complete circuit diagrams, refer to Wiring Diagrams.
1. Check the power seat circuit breaker in the junction block. If OK, go to Step 2. If not OK, replace the faulty power seat circuit breaker.
2. Check for battery voltage at the power seat circuit breaker in the junction block. If OK, go to Step 3. If not OK, repair the open fused B(+) circuit
to the fuse in the Power Distribution Center as required.
3. Remove the outboard seat cushion side shield from the seat. Disconnect the seat wire harness connector from the power seat switch connector
receptacle. Check for battery voltage at the fused B(+) circuit cavity of the power seat wire harness connector for the power seat switch. If OK, go
to Step 4. If not OK, repair the open fused B(+) circuit to the power seat circuit breaker in the junction block as required.
4. Check for continuity between the ground circuit cavity of the power seat wire harness connector for the power seat switch and a good ground.
There should be continuity. If OK, go to Step 5. If not OK, repair the open ground circuit to ground as required.
5. Test the power seat switch. Refer to Power Seat Switch Diagnosis and Testing in this group. If the switch tests OK, test the circuits of the power
seat wire harness between the inoperative power seat track adjuster motor and the power seat switch for shorts or opens. If the circuits check OK,
replace the faulty power seat track unit. If the circuits are not OK, repair the power seat wire harness as required.
