Chevrolet Trax: Radio controls malfunction (monochrome display)

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

The radio controls are supplied battery voltage and ground . The radio controls operate radio functions through serial data messages. The radio controls communicate control requests to the info display module through LIN serial data. The info display module communicates these control requests to the radio through serial data.

Diagnostic Aids

If the info display module is inoperative, the main radio controls will also be inoperative. The radio may be able to be operated with the steering wheel controls, if equipped.

Reference Information

Schematic Reference

Radio/Navigation System Schematics (Encore), Radio/Navigation System Schematics (Trax)

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

Radio/Audio System Description and Operation (with Monochrome Display), Radio/Audio System Description and Operation (with Color Display)

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

Display RPO UFD

1. Ignition ON, radio ON,
2. Verify the info display turns on and information is shown on the display.

• If the info display module does not turn on, or information is not shown in the display.

Refer to Radio Information Display Malfunction (Monochrome Display), Radio Information Display Malfunction (Color Display)

• If the info display turns on and information is shown on the display.

3. Verify that all radio controls operate and perform the correct function.

• If some, or all, of the radio controls do not operate normally.

Replace the A22 Radio Controls.

• If all radio controls operate and perform the correct function.

4. All OK.

Display RPO UAG

1. Ignition ON, A11 Radio ON.
2. Verify that all radio controls operate and perform the correct function.

If some, but not all, controls operate normally.

Replace the A22 Radio Controls.

If all controls are inoperative.

Refer to Circuit/System Testing

If all radio controls operate and perform the correct function.

3. All OK.

Circuit/System Testing

Display RPO UAG

1. Ignition OFF, disconnect the harness connector at the A22 Radio Controls.
2. Test for less than 10 ohms between the ground circuit terminal 3 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. Verify that a test lamp illuminates between the B+ circuit terminal 2 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, refer to Power Mode Mismatch .

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, replace the A22 Radio Controls.

If the test lamp illuminates.

4. Ignition ON.
5. Test for 2-11.5 V between the serial data circuit terminal 6 and ground.

If less than 2 V

1. Ignition OFF, disconnect the X1 harness connector at the P17 Info Display Module.
2. Test for infinite resistance between the serial data circuit and ground.

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

3. Test for less than 2 ohms in the serial data circuit end to end.

• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the P17 Info Display Module.

If greater than 11.5 V

1. Ignition OFF, disconnect the X1 harness connector at the P17 Info Display Module. Ignition ON.
2. Test for less than 1 V between the serial data circuit and ground.

• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V, replace the P17 Info Display Module.

If between 2-11.5 V

6. Test or replace the A22 Radio Controls.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• Driver Information Display Replacement (UAG) , Driver Information Display Replacement (UDN)
• Control Module References for radio control assembly replacement, programming, and setup.

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