Diagnosis And Testing - Driver Heated Seat Switch

If a heated seat fails to heat and one or both of the indicator lamps on a heated seat switch flash, refer to DIAGNOSIS AND TESTING  for flashing LED failure identification. Refer to SYSTEM WIRING DIAGRAMS for complete heated seat system wiring diagrams.

1. 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 DIAGNOSIS AND TESTING for heated seat module diagnosis and testing procedures. If not, go to step  2.
2. Remove the heated seat switch (Refer to ELECTRICAL/HEATED SEATS/DRIVER HEATED SEAT SWITCH - REMOVAL) . Check for continuity between the ground circuit cavity #5 of the heated seat switch connector and a good ground. There should be continuity. If OK, go to step  3. If not OK, repair the open ground circuit as required.
3. Turn the ignition switch to the ON position. Check for battery voltage at the fused ignition switch output circuit cavity #1 of the heated seat switch connector. If OK, go to step  4. If not OK, repair the open fused ignition switch output circuit as required.
4. Check the continuity between pin #1 and pin #3 of the heated seat switch. See Fig 1. If the readings do not correspond to those in TESTING HEATED SEAT SWITCH CONTINUITY , replace the heated seat switch. If OK, and the heated seat system is still not operating properly refer to DIAGNOSIS AND TESTING .

Fig 1: Rear View of Heated Seat Switches

Courtesy of DAIMLERCHRYSLER CORP.