Heated Seat Module-Front Seats

HEATED SEAT MODULE - FRONT SEATS

In order to obtain conclusive testing of the Memory Heated Seat Adjustable Pedal Module (MHSAPM), the Programmable Communications Interface (PCI) data bus circuit and any components that provide inputs to the module must be checked.

The most reliable, efficient, and accurate means to diagnose the MHSAPM requires the use of a diagnostic scan tool and the appropriate Diagnostic Information. The diagnostic scan tool can provide vital information to the technician trying to find a problem with the module. Diagnostic logic software is built into the MHSAPM to help locate the problem by the most efficient means possible. Anytime a problem is suspected, a diagnostic scan tool should be obtained and used to retrieve any stored fault codes in the MHSAPM. If diagnostic fault codes are present in the module, record them on a piece of paper immediately before proceeding with any diagnostic tests. Then, use these fault codes to identify the problem by verifying the fault code. Example, If the module records "DRIVER SEAT HEAT OUTPUT OPEN" fault, 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 corrected, erase the stored fault code using the diagnostic scan tool and verify correct heated seat system operation. If the heated seat system appears to be functioning correctly, verify that there are no other stored codes in the module and return the vehicle to service.

If the fault code could not be verified, such as not finding anything wrong when following the diagnostic flow chart in the Diagnostic Procedures Information, an INTERMITTENT problem may be present. You must than attempt to find the intermittent problem, such as moving the heating element within the seat while testing continuity or wiggling the wire harness's/electrical connectors under the seat while testing continuity. Always, eliminate all other potential problems before attempting to replace the MHSAPM.

For complete circuit wiring diagrams, refer to Diagrams/Electrical.

PRELIMINARY TEST

Before testing the individual components in the suspect system, check the following:

1. Using the diagnostic scan tool, check the MHSAPM for any stored fault codes. Record these codes on paper for reference and resolve using the appropriate Diagnostic Information.
2. Check the vehicles battery open-circuit voltage and charging system performance. If the vehicles electrical system is defective or weak it may not be suppling sufficient voltage to operate the system in question.