Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Heated Seat Back Only Mode Switch Signal | 2 | 2 | 2 | -- |
Heated Seat Back/Cushion Switch Signal | 1 | 1 | 1 | -- |
Heated Seat Cool Switch Signal | 3 | 3 | 3 | -- |
Heated Seat Back/Cushion Indicator Control | 4 | 4 | 4, 5 | -- |
Heated Seat Back Only Mode Indicator Control | 4 | 4 | 4, 5 | -- |
Heated Seat Cool Indicator Control | 4 | 4 | 4, 5 | -- |
Heated Seat High Temperature Indicator Control | 4 | 4 | 4, 5 | -- |
Heated Seat Low Temperature Indicator Control | 4 | 4 | 4, 5 | -- |
Heated Seat Medium Temperature Indicator Control | 4 | 4 | 4, 5 | -- |
Seat Temperature Control Switch Low Reference | 1 | 1 | -- | -- |
1. Heated seat back/cushion inoperative 2. Heated seat back only mode inoperative 3. Heated seat cool mode inoperative 4. Heated seat switch indicator inoperative 5. Heated seat switch indicator always on | ||||
Circuit/System Description
The driver and front passenger climate control seats are controlled by separate heated and cooled seat switches located on the door panels. When a heated or cool seat switch is pressed, ground is momentarily applied through the switch contacts and the switch signal circuit to the driver door module (DDM) or front passenger door module (FPDM). In response to this signal, the door module sends a serial data message to the memory seat module (MSM) indicating the heat or cool seat request. The door module then applies voltage through the appropriate indicator control circuits to the heated seat switch illuminating the appropriate indicators.
Reference Information
Schematic Reference
Connector End View Reference
Heated/Cooled Seat Component Views
Electrical Information Reference
Scan Tool Reference
Circuit/System Verification
Ignition ON, operate the heated and cooled seat switch through all three heat and cool modes of operation. The seat should activate in the appropriate heat or cool modes and the appropriate switch indicators should illuminate until the OFF position is reached.
| ⇒ | If any heated or cooled seat mode is inoperative, refer to Heated/Cooled Seats Inoperative. |
| ⇒ | If the heated and cooled seat operates normal, but the switch indicators do not illuminate or are always ON, refer to the Heated and Cooled Seat Switch Indicator component test. If the switch tests normal, replace the appropriate door module. |
Component Testing
Heated and Cool Seat Switch Indicator
- Ignition OFF, disconnect the C4 harness connector at the appropriate door module.
- Connect a 3A fused jumper wire between the low reference circuit terminal 4 and ground.
- Connect a test lamp between B+ and each control circuit terminal listed below. The appropriate indicator should illuminate.
| • | Seat back only heat mode indicator terminal 11 |
| • | Seat cool mode indicator terminal 12 |
| • | Seat back and cushion heat mode indicator terminal 10 |
| • | Low temperature indicator terminal 9 |
| • | Medium temperature indicator terminal 1 |
| • | High temperature indicator terminal 2 |
| ⇒ | If any indicator does not illuminate, replace the heated and cooled seat switch. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for door control module replacement, setup, and programming |
