Grand Cherokee 2WD V8-4.7L VIN N (2000)
Seat Heater Control Module: Testing and Inspection
Before testing the heated seat module, test the heated seat switch, the heated seat elements, and the heated seat sensor. Refer to Heated Seat Switch,
Heated Seat Element and Heated Seat Sensor in the Diagnosis and Testing. If testing of the heated seat switch, elements, and sensor reveals no problems,
proceed as follows.
1. Disconnect and isolate the battery negative cable. Disconnect both power seat wire harness connectors from the Heated Seat Module (HSM) or
Memory Heated Seat Module (MHSM). Check for continuity between each of the two Z1 ground circuit cavities of the C2 power seat wire
harness connector for the HSM or MHSM and a good ground. There should be continuity. If OK, go to Step 2. If not OK, repair the open ground
circuit to ground as required.
2. Check for continuity between the Z2 ground circuit cavity of the C1 power seat wire harness connector for the HSM or MHSM and a good ground.
There should be continuity. If OK, go to Step 3. If not OK, repair the open ground circuit to ground as required.
3. Reconnect the battery negative cable. Check for battery voltage at each of the two fused B(+) circuit cavities of the C2 power seat wire harness
connector for the HSM or MHSM. If OK, use a DRB scan tool and the proper Diagnostic Procedures to test the HSM or MHSM. If not OK, repair
the open fused B(+) circuit to the power seat circuit breaker in the junction block as required.
