With Memory A45 and KB6
Heated Seat Inoperative (With Memory A45 and KB6)
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.
Diagnostic Fault Information
Circuit/System Description
The driver and front passenger heated seats are controlled by separate heated seat switches. When a heated seat switch is pressed, ground is momentarily applied through the switch contacts and the switch signal circuit to the door lock/window switch. In response to this signal, the door lock/window switch sends serial data a message to the memory seat module (MSM) indicating the heat seat request. The door lock/window switch then applies voltage through the appropriate indicator control circuits to the heated seat switch illuminating the indicators.
Reference Information
Schematic Reference
Heated/Cooled Seat Schematics [1][2]Electrical DiagramsHeated/Cooled Seat Schematics [1][2]Electrical DiagramsHeated/Cooled Seat Schematics [1][2]Electrical Diagrams
Connector End View Reference
Component Connector End Views A/C Compressor Clutch
Description and Operation
Heated Seats Description and Operation Heated Seats
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
Scan Tool Reference
Control Module References Control Module References for scan tool information
Circuit/System Verification
1. Ignition ON, observe the appropriate scan tool Driver or Passenger Door Switch Seat Heat Mode Sw. parameter while pressing and releasing the heated seat switch. The readings should change between Inactive and Active.
• If not the specified value, refer to Heated and Cooled Seat Switch Malfunction.
2. If the heated seat switch function test normal, but, one or more of the heated seat switch indicators is inoperative or is always ON, refer to Heated and Cooled Seat Switch Indicator Malfunction.
3. If all scan tool parameters test normal and there are no DTCs set, replace the MSM.
Circuit/System Testing
Heated and Cooled Seat Switch Malfunction
1. Ignition OFF, disconnect the harness connector at the appropriate heated and cooled seat switch.
2. Ignition OFF, test for less than 10 omhs between the ground circuit terminal 7 and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance.
3. Ignition ON, verify the scan tool Seat Heat Mode Sw. parameter is Inactive.
• If not the specified value, test the signal circuit terminal 4 for a short to ground. If the circuit tests normal, replace the appropriate door lock/window switch.
4. Install a 3 A fused jumper wire between the signal circuit terminal 4 and ground. Verify the scan tool Seat Heat Mode Sw. parameter is Active.
• If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the appropriate door lock/window switch.
5. If all circuits test normal, test or replace the heated and cooled seat switch.
Heated and Cooled Seat Switch Indicator Malfunction
1. Ignition OFF, disconnect the harness connector at the appropriate heated and cooled seat switch.
2. Ignition ON, connect a test lamp between the control circuits listed below and ground. Command the Heated Seat Indicator ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.
* Seat heat mode indicator terminal 1
* Low indicator terminal 6
* Medium indicator terminal 8
* High indicator terminal 10
• If the test lamp is always ON, test the appropriate control circuit for a short to voltage. If the circuit tests normal, replace the door lock/window switch.
• If the test lamp is always OFF, test the appropriate control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the door lock/window switch.
3. If all circuits test normal, test or replace the heated and cooled seat switch.
Component Testing
Heated and Cooled Seat Switch
1. Ignition OFF, disconnect the harness connector at the appropriate heated and cooled seat switch.
2. Test for infinite resistance between the signal terminals listed below and the ground circuit terminal 7 with the switch in the open position:
* Cooled seat switch signal terminal 5
* Heated seat switch signal terminal 4
• If not the specified value, replace the heated and cooled seat switch.
3. Test for less than 2 omhs between the signal terminals listed below and the ground circuit terminal 7 with the appropriate switch in the closed position:
* Cooled seat switch signal terminal 5
* Heated seat switch signal terminal 4
• If greater than the specified range, replace the heated and cooled seat switch.
4. Connect a 3 A fused jumper wire between the ground circuit terminal 7 and ground.
5. Connect a test lamp between B+ and each control circuit terminal listed below. The appropriate indicator should illuminate.
* Seat heat mode indicator terminal 1
* Low indicator terminal 6
* Medium indicator terminal 8
* Seat cool mode indicator terminal 9
* High indicator terminal 10
• If any indicator does not illuminate, replace the heated and cooled seat switch.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.
* Driver Seat Heater Switch Replacement Driver Seat Heater Switch Replacement
* Passenger Seat Heater Switch Replacement Service and Repair
* Control Module References Control Module References for memory seat module and driver or passenger door lock/window switch replacement, programming, and setup