Adjustable Pedals Inoperative (with Memory)

Adjustable Pedals Inoperative (with memory)

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
* Review Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Circuit/System Description

The adjustable pedals assembly is moved forward or backward by a motor which is fixed to the brake pedal actuator with a drive cable to the accelerator pedal actuator. The adjustable pedals motor is controlled directly by an h-bridge driver circuit within the memory seat module. In an inactive state both of the outputs to the motor are supplied with a low current voltage of approximately 2.0 volts. The memory seat module controls the adjustable pedals motor by applying battery voltage to one of the outputs and ground to the other. The adjustable pedals motor is bidirectional and the direction of the pedal assembly travel is determined by which of the motor control circuits is switched to battery positive voltage while the other is grounded. The adjustable pedals forward and rearward switches are inputs to the memory seat module. The memory seat module supplies the switch assembly with a battery positive reference voltage. When the switch is operated to the forward or rearward direction, battery positive voltage is applied to the forward or rearward switch signal inputs.

Circuit/System Verification

1. Install a scan tool and display the MSM adjustable pedal information.
2. Verify that none of the switches are displayed as Active while in an inactive state.

^ If any of the switch inputs are Active, perform the Adjustable Pedal Switch Circuit Test.

3. Verify that the switch inputs are displayed as Active while the switch is pressed.

^ If any of the switch inputs remain Inactive while the switch is pressed, perform the Adjustable Pedal Switch Circuit Test.

4. If the switch inputs to the MSM function normal, perform the Motor Control Circuit Test.

Circuit/System Testing

Adjustable Pedal Switch Circuit Test
1. Disconnect the adjustable pedal switch connector and verify that neither of the adjuster switch inputs are displayed as Active.

^ If either of the switch inputs are displayed as Active, test the affected switch signal circuit for a short to voltage. If the circuit tests normal replace the MSM.

2. Verify that battery voltage is present at the reference voltage circuit terminal 5.

^ If battery voltage is not present, test the reference voltage circuit for an open/high resistance. If the circuit tests normal replace the MSM.

3. Connect a fused jumper wire from the reference voltage circuit terminal 5 to each of the switch signal circuit terminals 4 and 6, and verify that the switch inputs are displayed as Active when connected.

^ If the switch inputs are not Active with the jumper wire connected, test the affected switch signal circuit for an open/high resistance. If the circuit tests normal replace the MSM.

4. If the circuits test normal replace the adjustable pedal switch.

Motor Control Circuit Test
1. Disconnect the MSM connector C3.
2. Verify that a test lamp illuminates when connected from the high current battery supply circuit terminal 5 to ground.

^ If the test lamp does not illuminate, repair the high current battery supply circuit for an open or short to ground.

3. Connect the MSM connector C3 and disconnect the adjustable pedal motor connector.
4. Ignition on, verify that approximately 2 volts are present at the motor control circuit terminals.

^ If 2 volts are not present, repair the affected motor control circuit for an open/high resistance. If the circuits test normal replace the MSM.

5. If the circuits test normal replace the brake pedal assembly.

Repair Instructions

Perform the after completing the diagnostic procedure.

* Accessory Switch Replacement (Except Cadillac) Accessory Switch Replacement (Cadillac)
* Brake Pedal Assembly Replacement