Operation CHARM: Car repair manuals for everyone.

Through Model Year 2010






Heated Seat System

Preliminary Checks

Vehicles equipped with the heated seat option use a low voltage cut-off feature. This feature turns off power to the heated seat system anytime vehicle voltage is less than 11.7 volts or more than 15.5 volts. Be certain to check the vehicle electrical system for proper voltage anytime the power seat system appears inoperative.

Before testing the individual components in the heated seat system, check the following:

Check the vehicle battery open-circuit voltage and charging system performance. If the vehicle electrical system is defective or weak it may not be suppling sufficient energy to operate the heated seat system.

Using a diagnostic scan tool, check for any heated seat system related DTCs. Record these codes on paper for reference and resolve using the appropriate diagnostic information.

If the front heated seat system functions properly but the heated seat switch HI/LO LED indicators do not light with the ignition switch in the ON position and the heated seat switch in the low or high position, check the fused ignition switch fuse in the totally integrated power module. If OK, replace the HVAC control assembly. If not OK, repair the shorted circuit or component as required and replace the inoperative fuse.

If the 2nd row heated seat system functions properly but the heated seat switch HI/LO LED indicators do not light with the ignition switch in the ON position and the heated seat switch in the low or high position, check the fused ignition switch fuse in the totally integrated power module. If OK, replace the suspect heated seat switch. If not OK, repair the shorted circuit or component as required and replace the inoperative fuse.

Scan Tool Diagnosis

If diagnostic fault codes are present in the module, record them on a piece of paper immediately before proceeding any further. Then, use these fault codes to identify the problem by verifying the fault code. For example, if the module records "DRIVER SEAT HEAT OUTPUT OPEN" fault code, locate the diagnostic procedure for this code in the appropriate diagnostic information and follow the flow chart until the specific problem is located and resolved. Once the problem is thought to be corrected, erase the stored fault code using the diagnostic scan tool and verify correct system operation. If the heated seat system is functioning correctly, verify that there are no other stored codes and return the vehicle to service.

If the fault code could not be verified, this is a good indication that an intermittent problem may be present. You must then attempt to find the intermittent problem, such as moving the heating element within the seat while testing continuity or wiggling the wire harness/electrical connectors under the seat while testing continuity.