GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2008 🢒 Envoy - 4WD 🢒 Body Systems 🢒 Adjustable Pedals 🢒 Adjustable Pedals Malfunction

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 or High Resistance

Short to Voltage

Signal Performance

B+

1

1

--

--

Switch Control

1

1

--

--

Adjustable Pedals Relay Forward Control

B3607

B3607

2

--

Adjustable Pedals Relay Rearward Control

B3607

B3607

3

--

Electronic Adjustable Pedals (EAP) Motor Forward Control

1

1

2

--

Electronic Adjustable Pedals (EAP) Motor Rearward Control

1

1

3

--

Ground

--

B3607

--

--

1. Adjustable Pedal System Inoperative

2. Adjustable Pedals Fixed at Full Forward Position

3. Adjustable Pedals Fixed at Full Rearward Position

Circuit/System Description

The adjustable pedal motor control circuits are controlled by the adjustable pedal relay. The adjustable pedal relay may be controlled by either the memory seat module (MSM) or the adjustable pedal switch. In an inactive state both of the relay switch contacts are closed to the ground circuit. The relay coils are energized when battery voltage is supplied to the relay control circuits by either the MSM or the adjustable pedal switch. When the forward control or rearward control relay coil is energized the appropriate motor control circuit is switched to the battery voltage supply circuit contact.

Reference Information

Schematic Reference

Adjustable Pedal Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Adjustable Pedals 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 for scan tool information

Circuit/System Verification
  1. Verify DTCs B3606 or B3607 is not set.
    2. ⇒If any of the DTC are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle.
  2. Ignition ON, command the adjustable pedals forward and rearward with a scan tool.
    3. ⇒If the pedal assembly does not move as commanded, refer to Adjustable Pedals Motor Control Relay.
  3. Ignition OFF, operate the adjustable pedals forward and rearward with the adjustable pedal switch.
    4. ⇒If the pedal assembly does not move as commanded, refer to Adjustable Pedals Switch.
  4. Ignition ON, gear selector in DRIVE or REVERSE, operate the adjustable pedals from the adjustable pedals switch. Verify the pedal assembly DOES NOT move forward or rearward.
    5. ⇒If the pedal assembly moves, refer to Adjustable Pedals Underhood Relay (EAP Relay).

Circuit/System Testing

Adjustable Pedals Switch

  1. Ignition OFF, disconnect the harness connector at the adjustable pedal switch.
  2. Verify that a test lamp illuminates between the switch control circuit terminal C and ground.
    3. ⇒If the test lamp does not illuminate, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal and the circuit fuse is open, test the relay control circuit terminals A and B for a short to ground.
  3. Connect the harness connector at the adjustable pedal switch.
  4. Disconnect the harness connector at the adjustable pedal motor control relay.
  5. Connect a test lamp between the forward relay control circuit terminal A and ground.
  6. Operate the adjustable pedal switch between the neutral and Forward positions. The test lamp should turn ON and OFF when changing between the commanded states.
    7. ⇒If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the adjustable pedal switch.
    ⇒If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the adjustable pedal switch.
  7. Connect a test lamp between the rearward relay control circuit terminal F and ground.
  8. Operate the adjustable pedal switch between the neutral and Rearward positions. The test lamp should turn ON and OFF when changing between the commanded states.
    9. ⇒If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the adjustable pedal switch.
    ⇒If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the adjustable pedal switch.
  9. If all the circuits test normal, replace the adjustable pedal motor control relay.

Adjustable Pedals Motor Control Relay

  1. Ignition OFF, disconnect the adjustable pedal motor control relay.
  2. Test for less than 10 ohms between the ground circuit terminal D and ground.
    3. ⇒If greater than the specified range, test the ground circuit for an open/high resistance.
  3. Verify that a test lamp illuminates between the B+ circuit terminal C and ground.
    4. ⇒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 and the B+ circuit fuse is open, test the adjustable pedal motor control circuits for a short to ground if the circuits test normal replace the adjustable pedal assembly.
  4. Connect a test lamp between the control circuit terminal A and ground.
  5. Command the Pedals Forward and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.
    6. ⇒If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the MSM.
    ⇒If the test lamp is always OFF, test the control circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the MSM.
  6. Connect a test lamp between the control circuit terminal F and ground.
  7. Command the Pedals Rearward and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.
    8. ⇒If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the MSM.
    ⇒If the test lamp is always OFF, test the control circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the MSM.
  8. Connect the adjustable pedal motor control relay.
  9. Disconnect the harness connector at the adjustable pedal assembly.
  10. Ignition OFF, test for less than 10 ohms between the control circuit terminal 4 and ground.
    11. ⇒If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If circuits test normal, replace the adjustable pedal motor control relay.
  11. Ignition OFF, test for less than 10 ohms between the control circuit terminal 5 and ground.
    12. ⇒If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If circuits test normal, replace the adjustable pedal motor control relay.
  12. Connect a test lamp between control circuit terminal 4 and control circuit terminal 5.
  13. Command the Pedals Forward and Rearward with a scan tool. The test lamp should turn ON when commanding the Forward and Rearward states.
    14. ⇒If the test lamp remains OFF during either of the commands, test for a short to ground on either control circuit. If the circuits test normal, replace the adjustable pedal motor control relay.
  14. If all circuits test normal, test or replace the adjustable pedal assembly.

Adjustable Pedals Underhood Relay (EAP Relay)

  1. Refer to Automatic Transmission Shift Lock Control Description and Operation. Verify the shift lock control operates as described.
    2. ⇒ If the shift lock control does not operate properly, refer to Symptoms - Automatic Transmission Shift Lock Control.
  2. Ignition OFF, disconnect the EAP relay.
  3. Connect a test lamp between the relay switch B+ circuit and ground. Verify the test lamp illuminates.
    4. ⇒ If the test lamp does not illuminate, test the relay switch B+ circuit for a short to ground or an open/high resistance.
  4. Connect a test lamp between the relay switch B+ circuit and the relay coil ground. Verify the test lamp illuminates.
    5. ⇒If the test lamp does not illuminate, test the relay coil ground circuit for an open or high resistance.
  5. Ignition ON, connect a test lamp between the relay coil ignition voltage circuit and ground. Verify the test lamp illuminates.
    6. ⇒ If the test lamp does not illuminate, test the relay coil ignition voltage circuit for a short to ground or an open/high resistance.
  6. Ignition ON, gear selector in PARK. Connect a test lamp between the relay switch PNP controlled input circuit and ground. Verify the test lamp illuminates.
    7. ⇒ If the test lamp does not illuminate, test the relay switch PNP controlled input circuit for a short to ground or an open/high resistance.
  7. Gear selector in DRIVE or REVERSE. Verify the test lamp does not illuminate.
    8. ⇒ If the test lamp illuminates, test the relay switch PNP controlled input circuit for a short to voltage.
  8. Ignition OFF, reconnect the EAP relay. Disconnect the adjustable pedals switch.
  9. Connect a test lamp between the adjustable pedals switch harness connector terminal C and ground. Verify the test lamp illuminates.
    10. ⇒ If the test lamp does not illuminate, test the relay switch controlled output circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the EAP relay.
  10. Ignition ON, gear selector in PARK. Verify the test lamp illuminates.
    11. ⇒ If the test lamp does not illuminate, replace the EAP relay.
  11. Gear selector in DRIVE or REVERSE. Verify the test lamp does not illuminate.
    12. ⇒ If the test lamp illuminates, replace the EAP relay.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Brake Pedal Assembly Replacement