Seat Temperature Control Module: Testing and Inspection

The heated seat module is also known as the Seat Heat Interface Module or SHIM.
1. If a heated seat fails to heat and one or both of the LED indicator lamps on a heated seat switch flash, refer to heated seat system diagnosis and testing procedures. If a heated seat heats, but one or both LED indicator lamps on the heated seat switch fail to operate, refer to the appropriate heated seat switch diagnosis and testing procedure. If the heated seat switch checks OK, go to Step 4. If both seats (driver and passenger) fail to heat and the LED indicator lamps on the heated seat switches for both seats fail to operate, refer to the heated seat relay diagnosis and testing procedure. If the heated seat relay checks OK, go to Step 2. If only one seat (driver or passenger) fails to heat and the LED indicator lamps on the heated seat switch for that seat fail to operate, refer to the heated seat switch diagnosis and testing procedure. If the heated seat switch checks OK, go to Step 3. If a heated seat switch LED indicator lamp remains illuminated after the heated seat has been turned Off, go to Step 5.
2. Disconnect and isolate the battery negative cable. Disconnect the power seat wire harness connector from the SHIM connector receptacle. Check for continuity between the ground circuit cavity of the wire harness connector for the SHIM and a good ground. If OK, go to Step 3. If not OK, repair the open ground circuit to ground (G306) as required.
3. Disconnect and isolate the battery negative cable. Disconnect the power seat wire harness connector from the SHIM connector receptacle. Remove the heated seat switches from the center floor console. Disconnect the power seat wire harness connector(s) from the connector receptacle(s) of the inoperative heated seat switch(es). Check for continuity between the inoperative driver and/or passenger seat heater switch MUX circuit cavities of the power seat wire harness connector(s) for the inoperative heated seat switch and the power seat wire harness connector for the SHIM. There should be continuity. If OK, replace the faulty SHIM. If not OK, repair the open driver and/or passenger seat heater switch MUX circuit as required.
4. Disconnect and isolate the battery negative cable. Disconnect the power seat wire harness connector from the SHIM connector receptacle. Remove the heated seat switches from the center floor console. Disconnect the power seat wire harness connector(s) from the connector receptacle(s) of the heated seat switch(es) with the inoperative LED indicator lamp(s). Check for continuity between the inoperative driver and/or passenger seat high and/or low heat LED driver circuit cavities of the power seat wire harness connector(s) for the heated seat switch(es) and the power seat wire harness connector for the SHIM. There should be continuity. If OK, replace the faulty SHIM. If not OK, repair the open driver or passenger seat high or low heat LED driver circuit as required.
5. Disconnect and isolate the battery negative cable. Disconnect the power seat wire harness connector from the SHIM connector receptacle. Remove the heated seat switches from the center floor console. Disconnect the power seat wire harness connector(s) from the connector receptacle(s) of the heated seat switch(es) with the inaccurate LED indicator lamp(s). Check for continuity between the inoperative driver and/or passenger seat high and/or low heat LED driver circuit cavity of the power seat wire harness connector(s) for the heated seat switch(es) and a good ground. There should be no continuity. If OK, replace the faulty SHIM. If not OK, repair the shorted driver or passenger seat high or low heat LED driver circuit as required.