GM Service Manual Online
For 1990-2009 cars only

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.

DTC Descriptors

DTC B1545 00: Seat Stow Switch 1 Circuit

DTC B1546 00: Seat Stow Switch 2 Circuit

DTC B3729 00: Seat Recline Control Switch

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

B+, Folding Seat Switch

1

1

--

--

Folding Seat Front Stow Switch Signal

1

1

B1545 00

--

Folding Seat Recline Switch Signal

1

1

B3729 00

--

Folding Seat Rear Stow Switch Signal

1

1

B1546 00

--

1. Power Third Row Seat Inoperative

Circuit/System Description

When the rear folding seat stow or recline switches are pressed they send a 12-volt signal through the switch signal circuit to the rear seat module (RSM). The RSM then commands the rear folding seat to move in response to the switch inputs.

Conditions for Running the DTC

    • DTC B1325 must not be present.
    • Battery voltage must be between 9-16 volts.

Conditions for Setting the DTC

If a switch input continues to be active for a period of time after motion in the requested direction has ceased, the switch under test will be considered shorted.

Action Taken When the DTC Sets

    • A motor output driven in response to a switch considered failed, is deactivated for both directions.
    • The RSM will respond to any other switch signal that has not set a DTC.

Conditions for Clearing the DTC

The DTC automatically clears when the switch circuit setting the DTC is no longer active.

Reference Information

Schematic Reference

Rear Seat Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Power Seats System Description and Operation

Electrical Information Reference

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

Scan Tool Reference

Control Module References

Circuit/System Verification

Ignition ON, observe the scan tool Rear Seat Module parameters listed below while pressing the appropriate folding seat switch. The reading should change between Inactive and Active.

    • Front Stow Switch
    • Rear Stow Switch
    • Recline Switch

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at the appropriate folding seat stow or recline switch.
  2. Ignition ON, verify the scan tool Rear Seat Module parameters listed below are Inactive.
  3. • Front Stow Switch
    • Rear Stow Switch
    • Recline Switch
    If not the specified value, test the appropriate signal circuit for a short to voltage. If the circuit tests normal, replace the RSM.
  4. If all circuits test normal, test or replace the folding seat switch.

Component Testing

  1. Ignition OFF, disconnect the harness connector at the folding seat stow switch.
  2. Test for infinite resistance between signal terminal C and the B+ terminal A with the switch in the open position.
  3. If less than the specified value, replace the switch.
  4. Test for less than 1 ohm of resistance between signal terminal C and the B+ terminal A with the switch in the closed position.
  5. If greater than the specified value, replace the folding seat stow switch.

Repair Instructions

Important: After performing this diagnostic test and electrical or component repairs have been completed, the folding seat may be in an unknown state and out of calibration with the RSM. The RSM must be calibrated before the folding seat system will operate. Refer to Power Folding Seat Calibration .

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Rear Seat Number 2 Folding Actuator Switch Replacement - Rear Quarter Trim Front
    •  Rear Seat Number 2 Folding Actuator Switch Replacement - Rear Quarter Trim Rear
    •  Control Module References for RSM replacement, setup, and programming