Heated/Cooled Seat Switch Indicator Malfunction

HEATED/COOLED SEAT SWITCH INDICATOR MALFUNCTION

DIAGNOSTIC FAULT INFORMATION




Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview

CIRCUIT/SYSTEM DESCRIPTION
The driver and front passenger climate control seats are controlled by separate heated and cooled seat switches. The switches are 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 door module. In response to this signal, the module then sends a message to the memory seat module via the low speed GMLAN serial data line 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.

CIRCUIT/SYSTEM VERIFICATION
1. Ignition ON with the heated and cooled seat OFF, the heated and cooled seat switch mode indicators should not be illuminated.
- If illuminated, refer to the Heated and Cooled Seat Switch Indicators Always On Circuit/System Testing.
2. Ignition ON, use a scan tool to observe the appropriate Seat Switch Seat Indicator Cmd. parameter while pressing the heated seat switch. The reading should change between Off and On.
- If not On, refer to the Heated and Cooled Seat Switch Indicators Inoperative Circuit/System Testing.

CIRCUIT/SYSTEM TESTING

Driver Heated and Cooled Seat Switch Indicators Inoperative
1. Ignition OFF, disconnect the harness connector at the heated and cooled seat switch.
2. Ignition OFF, test for less than 10 ohms of resistance between the heated and cooled seat switch low reference circuit terminal 3 and ground.
- If greater than 10 ohms, test the ground circuit for an open/high resistance. If the circuit tests normal, replace the door module.
3. Connect the harness connector at the heated and cooled seat switch.
4. Ignition OFF, disconnect the (C4) harness connector at the door module.
5. Connect a 3A fused jumper wire between the low reference circuit terminal 4 and ground.
6. Connect a test lamp between each indicator control circuit terminal and battery voltage. Each indicator should illuminate when tested.
- If any indicator does not illuminate, test the appropriate control circuit for short to ground or an open/high resistance. If the circuit test normal, replace the heated and cooled seat switch.
7. If all indicators illuminate, replace the door module.

Passenger Heated and Cooled Seat Switch Indicators Inoperative
1. Ignition OFF, disconnect the harness connector at the heated and cooled seat switch.
2. Ignition OFF, test for less than 10 ohms of resistance between the heated seat switch low reference circuit terminal 5 and ground.
- If greater than 10 ohms, test the ground circuit for an open/high resistance. If the circuit tests normal, replace the door module.
3. Connect the harness connector at the heated and cooled seat switch.
4. Ignition OFF, disconnect the (C4) harness connector at the door module.
5. Connect a 3A fused jumper wire between the low reference circuit terminal 4 and ground.
6. Connect a test lamp between each indicator control circuit terminal and battery voltage. Each indicator should illuminate when tested.
- If any indicator does not illuminate, test the appropriate control circuit for short to ground or an open/high resistance. If the circuit test normal, replace the heated and cooled seat switch.
7. If all indicators illuminate, replace the door module.

Heated and Cooled Seat Switch Indicators Always On
1. Ignition OFF, disconnect the harness connector at the heated and cooled seat switch.
2. Ignition ON, heated and cool seat OFF. Test for less than 0 volts between the illuminated indicator control circuit and ground.
- If greater than 0 volts, test the control circuit for a short to voltage. If the circuit tests normal, replace the door module.

REPAIR INSTRUCTIONS
Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests
- Heated and Cooled Seat Switch Replacement
- Control Module References for door module replacement, setup, and programming. Programming and Relearning