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.

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Switch Reference Voltage

1

1

--

--

Adjustable Pedals Forward Switch Signal

1

1

B3604 01

--

Adjustable Pedals Rearward Switch Signal

1

1

B3605 01

--

Adjustable Pedals Motor Forward Control

B3920 02

B3606 61

B3920 01

B3606 5A

Adjustable Pedals Motor Rearward Control

B3920 02

B3606 61

B3920 01

B3606 5A

1. Adjustable Pedals Inoperative

Circuit/System Description

Battery voltage is supplied at all times to the adjustable pedal switch from the IGN SW fuse located in the underhood fuse block. When the pedal switch is operated to move the pedals forward, battery positive voltage is applied through the switch contacts and the adjustable pedal forward switch signal circuit to the MSM. In response to this signal, the MSM applies battery voltage through the adjustable pedal motor forward control circuit and ground through the adjustable pedal motor rearward control circuit to the motor. The motor runs to move the pedals forward until the switch is released. Moving the pedals rearward works similarly to moving the pedals forward, except that battery positive voltage and ground are applied on the opposite circuits causing the motor to run in the opposite direction.

Diagnostic Aids

The Memory Seat Module (MSM) may be referenced as the Driver Position Module.

Reference Information

Schematic Reference

Adjustable Pedal Schematics

Connector End View Reference

    •  Adjustable Pedal Component Views
    •  Power and Grounding Connector End Views

Electrical Information Reference

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

Circuit/System Verification

Ignition ON, observe the scan tool adjustable pedal switch parameters while pressing and releasing the pedal switch in both directions. The reading should change between Inactive and Active for both directions.

Circuit/System Testing

Switch Circuit Test

  1. Ignition OFF, disconnect the harness connector at the adjustable pedals switch.
  2. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal C and ground.
  3. If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the memory seat module.
  4. Install a 3-A fused jumper wire between the inoperative switch signal circuit terminal and the B+ circuit terminal C. Verify the related scan tool Adjustable Pedal Switch parameter is Active.
  5. If not Active, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the memory seat module.
  6. If all circuits test normal, test or replace the adjustable pedal switch.

Component Testing

  1. Ignition OFF, disconnect the harness connector at the adjustable pedal switch.
  2. Test for infinite resistance between the signal terminal A and the B+ terminal C with the switch in the open position.
  3. If not the specified value, replace the adjustable pedal switch.
  4. Test for less than 2 ohms of resistance between the signal terminal A and the B+ terminal C with the switch in the closed position.
  5. If greater than the specified range, replace the adjustable pedal switch.
  6. Test for infinite resistance between the signal terminal B and the B+ terminal C with the switch in the open position.
  7. If not the specified value, replace the adjustable pedal switch.
  8. Test for less than 2 ohms of resistance between the signal terminal B and the B+ terminal C with the switch in the closed position.
  9. If greater than the specified range, replace the adjustable pedal switch.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Brake and Accelerator Pedal Adjuster Switch Replacement
    •  Brake and Accelerator Pedal Adjuster Actuator Motor Replacement
    •  Control Module References for the memory seat module replacement and setup procedures