Chevrolet Trax: Power seat malfunction (without memory A45)

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/System Description

Battery voltage is supplied at all times to the seat adjuster switch through a 30 A fuse located in the rear body fuse block. When the seat switch is in a inactive state, the switch contacts are closed to the switch ground circuit.

All seat motors are reversible. For example, when the seat horizontal forward switch is pressed to move the entire seat forward, B+ is applied through the switch contacts and the seat horizontal motor forward control circuit to the motor. With the horizontal motor rearward switch contacts closed to the switch ground circuit, the motor runs in order to drive the entire seat forward until the switch is released. Moving the entire seat rearward works similarly to moving the entire seat forward, except that battery voltage and ground are applied on opposite circuits causing the motor to run in the opposite direction. All seat motors are powered this way.

Reference Information

Schematic Reference

• Driver Seat Schematics (Encore), Driver Seat Schematics (Trax)
• Passenger Seat Schematics (Encore)

Connector End View Reference

WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - ENCORE WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - TRAX

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

Circuit/System Verification

1. Verify the driver or passenger power seat directional motors listed below operate when operating the seat switches in both directions.

• M50 Seat Front Vertical Motor
• M51 Seat Horizontal Motor
• M55 Seat Rear Vertical Motor

If all seat motors do not operate

Refer to Circuit/System Testing - Seat Adjuster Switch Circuit Test.

If 1 or more seat motors operate

Refer to Circuit/System Testing - Seat Motor Circuit Test.

2. All OK.

Circuit/System Testing

Seat Adjuster Switch Circuit Test

1. Ignition OFF, disconnect the harness connector at the appropriate S64 Seat Adjuster Switch.
2. Test for less than 10 ohms between the ground circuit terminal B and ground.

If 10 ohms or greater

1. Ignition OFF.
2. Test for less than 2 ohms in the ground circuit end to end.

• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, repair the open/high resistance in the ground connection.

If less than 10 ohms

3. Ignition ON.
4. Verify a test lamp illuminates between the B+ circuit terminal D and ground.

If the test lamp does not illuminate and the circuit fuse is good

1. Ignition OFF
2. Test for less than 2 ohms in the B+ circuit end to end.

• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, verify the circuit breaker is not open and there is voltage at the circuit breaker.

If the test lamp does not illuminate and the circuit fuse is open

1. Ignition OFF.
2. Test for infinite resistance between the B+ circuit and ground.

• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance

3. Test for greater than 10 ohms between each signal circuit listed below and ground:

• Control circuit terminal E - M50 Seat Front Vertical Motor
• Control circuit terminal G - M50 Seat Front Vertical Motor
• Control circuit terminal A - M55 Seat Rear Vertical Motor
• Control circuit terminal H - M55 Seat Rear Vertical Motor
• Control circuit terminal F - M51 Seat Horizontal Motor
• Control circuit terminal C - M51 Seat Horizontal Motor

If 10 ohms or less, disconnect the harness connector at the seat motor and retest to verify if the short is in the circuit or the component.

If greater than 10 ohms, test or replace the S64 Seat Adjuster Switch.

If the test lamp illuminates

5. Test or replace the S64 Seat Adjuster Switch.

Seat Motor Circuit Test

1. Ignition OFF, disconnect the harness connector at the appropriate seat motor listed below:

• M51 Seat Horizontal Motor
• M50 Seat Front Vertical Motor
• M55 Seat Rear Vertical Motor

2. Connect a test lamp between control circuit terminal 1 and control circuit terminal 3, ignition ON.
3. Verify the test lamp turns ON when commanding the seat motor Up and Down or Forward and Rearward using the seat adjuster switch.

If the test lamp does not turn ON during either of the commands

1. Ignition OFF, disconnect the harness connector at the S64 Seat Adjuster Switch.
2. Test for less than 2 ohms in each control circuit end to end.

If 2 ohms or greater, repair the open/high resistance in the circuit.

If less than 2 ohms, test or replace the S64 Seat Adjuster Switch

If the test lamp turns ON during each of the commands

4. Test or replace the seat motor.

Component Testing

Seat Adjuster Switch

1. Ignition OFF, disconnect the harness connector at the S64 Seat Adjuster Switch.
2. Test for infinite resistance between the B+ terminal D and each control terminal with the switch in the open position.

If less than infinite resistance

Replace the S64 Seat Adjuster Switch.

3. Test for less than 2 ohms between the B+ terminal D and each control terminal with the appropriate switch in the closed position.

If 2 ohms or greater

Replace the S64 Seat Adjuster Switch.

If less than 2 ohms

4. Test for less than 2 ohms between the ground terminal B and each control terminal listed below with the switch in the open position.

If 2 ohms or greater

Replace the S64 Seat Adjuster Switch.

If less than 2 ohms

5. All OK.

Seat Motor

1. Ignition OFF, disconnect the harness connector at the appropriate seat motor listed below:

• M51 Seat Horizontal Motor
• M50 Seat Front Vertical Motor
• M55 Seat Rear Vertical Motor

NOTE: When performing the following tests, make sure that the seat is not already in the position the test is attempting to produce.

2. Install a 30 A fused jumper wire between control terminal 1 and 12 V.
3. Momentarily install a jumper wire between control terminal 3 and ground. The seat motor should momentarily perform the appropriate FORWARD/ REARWARD/ UP/ DOWN function.

If the motor does not perform the FORWARD/ REARWARD/ UP/ DOWN function

Replace the motor.

If the motor performs the FORWARD/ REARWARD/ UP/ DOWN function

4. Reverse the jumper wires; the motor should perform UP/ DOWN function.

If the motor does not perform the FORWARD/ REARWARD/ UP/ DOWN function

Replace the motor.

If the motor performs the FORWARD/ REARWARD/ UP/ DOWN function

5. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

• Driver or Passenger Seat Adjuster Switch Replacement
• Front Seat Tilt Adjuster Actuator Replacement
• Driver or Passenger Seat Vertical Adjuster Actuator Replacement
• Front Seat Adjuster Actuator Replacement

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