Seat Temperature Switch: Testing and Inspection

WARNING: ON VEHICLES EQUIPPED WITH AIRBAGS, DISABLE THE AIRBAG SYSTEM BEFORE ATTEMPTING ANY STEERING WHEEL, STEERING COLUMN, OR INSTRUMENT PANEL COMPONENT DIAGNOSIS OR SERVICE. DISCONNECT AND ISOLATE THE BATTERY NEGATIVE (GROUND) CABLE, THEN WAIT TWO MINUTES FOR THE AIRBAG SYSTEM CAPACITOR TO DISCHARGE BEFORE PERFORMING FURTHER DIAGNOSIS OR SERVICE. THIS IS THE ONLY SURE WAY TO DISABLE THE AIRBAG SYSTEM. FAILURE TO TAKE THE PROPER PRECAUTIONS COULD RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL INJURY.

1. If the problem being diagnosed involves inoperative heated seat switch back lighting and the cluster illumination lamps operate, go to Step 2. If the problem being diagnosed involves inoperative heated seat switch back lighting and the cluster illumination lamps are also inoperative, refer to cluster illumination lamps diagnosis and testing procedures. If the problem being diagnosed involves inoperative heated seat switch indicator lamps and the heated seat elements do not heat, refer to Step 4. If the problem being diagnosed involves inoperative heated seat switch indicator lamps and the heated seat elements do heat, go to Step 8. If the problem being diagnosed involves a heated seat switch indicator lamp that remains illuminated after the heated seat has been turned Off, refer to Heated Seat Module diagnosis and testing procedures.
2. Disconnect and isolate the battery negative cable. Remove the heated seat switch and bezel unit from the instrument panel. Disconnect the instrument panel wire harness connector from the connector receptacle on the back of the heated seat switch to be tested. Check for continuity between the ground circuit cavity of the instrument panel wire harness connector for the heated seat switch 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. Turn the park lamps on with the headlamp switch. Rotate the panel lamps dimmer thumbwheel on the headlamp switch upward to just before the interior lamps detent. Check for battery voltage at the fused panel lamps dimmer switch signal circuit cavity of the instrument panel wire harness connector for the heated seat switch. If OK, replace the faulty heated seat switch. If not OK, repair the open fused panel lamps dimmer switch signal circuit to the fuse in the Junction Block (JB) as required.
4. Check the fused ignition switch output (run) fuse in the Junction Block (JB). If OK, go to Step 5. If not OK, repair the shorted circuit or component as required and replace the faulty fuse.
5. Turn the ignition switch to the ON position. Check for battery voltage at the fused ignition switch output (run) fuse in the JB. If OK, go to Step 6. If not OK, repair the open fused ignition switch output (run) circuit to the ignition switch as required.
6. Disconnect and isolate the battery negative cable. Remove the heated seat switch and bezel unit from the instrument panel. Disconnect the instrument panel wire harness connector from the connector receptacle on the back of the heated seat switch to be tested. Reconnect the battery negative cable. Turn the ignition switch to the ON position. Check for battery voltage at the fused ignition switch output (run) circuit cavity of the instrument panel wire harness connector for the heated seat switch. If OK, go to Step 7. If not OK, repair the open fused ignition switch output (run) circuit to the JB fuse as required.

Heated Seat Switch:

Heated Seat Switch Continuity:

7. Check the continuity and resistance values of the heated seat switch in the Neutral, Low and High positions as shown in the Heated Seat Switch Continuity chart. If OK, refer to Heated Seat Module diagnosis and testing procedures. If not OK, replace the faulty heated seat switch.
8. Replace the inoperative heated seat switch with a known good unit and test the operation of the switch indicator lamps. If OK, discard the faulty heated seat switch. If not OK, refer to Heated Seat Module diagnosis and testing procedures.