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For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2007 🢒 DTS 🢒 Diagnostic Navigation 🢒 Vehicle Diagnostic Information 🢒 Heated Seat Inoperative - Rear

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 Switch Ground

1

1

--

--

Heated Seat Switch Indicator Supply Voltage

3

3

--

--

Heated Seat Back Only Indicator Control

4

3

3

--

Heated Seat Back Only Mode Switch Signal

2

2

2

--

Heated Seat Back/Cushion Indicator Control

4

3

3

--

Heated Seat Low Temperature Indicator Control

4

3

3

--

Heated Seat Medium Temperature Indicator Control

4

3

3

--

Heated Seat High Temperature Indicator Control

4

3

3

--

Heated Seat Temperature Switch Signal

1

1

1

--

1. Heated seat inoperative

2. Heated seat back only mode inoperative

3. Heated seat switch indicator inoperative

4. Heated seat switch indicator always on

Circuit/System Description

The left and right rear passenger heated seats are controlled by separate heated seat switches. The switches are located on the rear door panels. When a heated seat switch is pressed, ground is momentarily applied through the switch contacts and the switch signal circuit to the rear heated seat module. In response to this signal, the module then applies battery voltage through the element supply voltage circuits to the seat cushion and seat back heating elements. The heated seat module then supplies a ground through the appropriate indicator control circuits to the heated seat switch illuminating the switch indicators.

Reference Information

Schematic Reference

Heated/Cooled Seat Schematics

Connector End View Reference

Heated/Cooled Seat Component Views

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Scan Tool Reference

    •  Scan Tool Data List
    •  Scan Tool Data Definitions

Circuit/System Verification
  1. Ignition ON, use a scan tool to observe the Rear Heated Seat Module Rear Seat HVC Mode parameter while pressing the heated seat back and cushion switch. The reading should change between Off and Back and Cushion.
    2. ⇒If not Back and Cushion, perform the Circuit/System Testing.
  2. While observing the Rear Seat HVC Mode parameter, press the heated seat back only mode switch. The reading should change between Back and Cushion and Back Only.
    3. ⇒If not Back Only, perform the Circuit/System Testing.
  3. If both Rear Seat HVC Mode parameters displayed correctly and there are no DTCs set, replace the heated seat module.

Circuit/System Testing
  1. Ignition OFF, disconnect the harness connector at the heated seat switch.
  2. Test for less than 5 ohms of resistance between the heated seat switch ground circuit terminal J and ground.
    3. ⇒If greater than 5 ohms, repair the ground circuit for an open/high resistance.
  3. Ignition ON, use a scan tool to observe the Rear Heated Seat Module Rear Seat HVC Mode parameter. The reading should be Off.
    4. ⇒If not Off, test the appropriate signal circuit for a short to ground. If the circuit tests normal, replace the heated seat module.
  4. Install a 3A fused jumper wire between the switch signal circuit terminal G and ground. Verify the Rear Seat HVC Mode parameter is Back and Cushion.
    5. ⇒If not Back and Cushion, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the heated seat module.
  5. Install a 3A fused jumper wire between the switch signal circuit terminal A and ground. Verify the Rear Seat HVC Mode parameter is Back Only.
    6. ⇒If not Back Only, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the heated seat module.
  6. If all circuits tests normal, test or replace the heated seat switch.

Component Testing

Rear Heated Seat Switch

  1. Ignition OFF, disconnect the harness connector at the heated seat switch switch.
  2. Test for infinite resistance between the signal terminal G and the ground terminal J with the back and cushion switch in the open position.
    3. ⇒If less than infinite, replace the heated seat switch switch.
  3. Test for infinite resistance between the signal terminal A and the ground terminal J with the back only switch in the open position.
    4. ⇒If less than infinite, replace the heated seat switch switch.
  4. Test for less than 5 ohms between the signal terminal G and the ground terminal J with the back and cushion switch in the closed position.
    5. ⇒If greater than 5 ohms, replace the heated seat switch.
  5. Test for less than 5 ohms between the signal terminal A and the ground terminal J with the back only switch in the closed position.
    6. ⇒If greater than 5 ohms, replace the heated seat switch.
  6. Connect a 3A fused jumper wire between the heated seat switch supply voltage terminal K and battery voltage.
  7. Connect a test lamp between the following indicator control circuits and ground. The selected indicator should illuminate.
    8. • Terminal B seat back only mode indicator
    • Terminal C low heat indicator
    • Terminal D medium heat indicator
    • Terminal E high heat indicator
    • Terminal H seat back cushion mode indicator
         ⇒If any of the indicators do not illuminate, replace the rear heated seat switch.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Rear Seat Heater Switch Replacement
    •  Control Module References for heated seat module replacement, setup, and programming