Operation CHARM: Car repair manuals for everyone.
Home >> Buick >> 2012 >> Verano L4-2.4L >> Repair and Diagnosis >> A L L Diagnostic Trouble Codes ( DTC ) >> Testing and Inspection >> U Code Charts >> U0257 >> With Color Display

With Color Display




Radio Information Display Malfunction - DTC U0257 (with Color Display)

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.

* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Diagnostic Fault Information






Circuit/System Description

The radio info display module is supplied battery voltage and ground. The radio controls the power state of the display through the remote enable circuit, which is also used to control the power state of other infotainment devices. The info display module receives digital video data from the radio for on-screen display information through the video signal circuits. The radio communicates with the info display module over the touch screen serial data circuits for touch screen inputs and backlighting dimming level.

Reference Information

Schematic Reference

Radio/Navigation System Schematics Radio/Navigation System Schematics

Connector End View Reference

Component Connector End Views Outside Rearview Mirror - Driver

Description and Operation

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

Electrical Information Reference

* Circuit Testing Circuit Testing

* Connector Repairs Connector Repairs

* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections

* Wiring Repairs Wiring Repairs

Scan Tool Reference

Control Module References Control Module References for scan tool information

Circuit/System Verification

1. Verify DTC B1265 is not set.

• If DTC B1265 is set.
Refer to Diagnostic Trouble Code (DTC) List - Vehicle Diagnostic Trouble Code (DTC) List - Vehicle.

• If DTC B1265 is not set.

2. Ignition ON, radio ON.

3. Verify the P17 info display module turns on and information is shown on the display.

• If the P17 info display module does not turn on, or information is not shown in the display.
Refer to Circuit/System Testing

• If the P17 info display module turns on and information is shown on the display.

4. All OK.

Circuit/System Testing

1. Ignition OFF.

2. Verify the video interface cable is properly connected at the P17 info display module X2 and A11 radio X5 connections and there is no damage to the cable or connections.

• If connection problems or cable damage is noted.
Perform the appropriate repair or replacement to correct any issues.

• If no issues are found with the video interface cable.

3. Disconnect the X1 harness connector at the P17 info display module.

4. Test for less than 10 ohms between the ground circuit terminal 2 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

5. Test for less than 20 ohms between the data shield circuit terminal 7 and ground.

• If 20 ohms or greater

1. Ignition OFF, disconnect the X4 connector at the A11 radio.

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

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

• If less than 2 ohms, replace the A11 radio.

• If less than 20 ohms

6. Verify that a test lamp illuminates between the B+ circuit terminal 1 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 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 P17 info display module.

• If the test lamp illuminates.

7. Ignition ON, radio ON.

8. Verify that a test lamp illuminates between the control circuit terminal 6 and ground.

• If the test lamp does not illuminate.

1. Ignition OFF, disconnect the X1 harness connector at the A11 radio.

2. Test for infinite resistance between the control 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 control circuit end to end.

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

• If less than 2 ohms, replace the A11 radio.

• If the test lamp illuminates.

9. Test for 2-3 V between the data circuit terminals listed below and ground.

* terminal 4

* terminal 8

• If less than 2 V

1. Ignition OFF, disconnect the X4 harness connector at the A11 radio.

2. Test for infinite resistance between the 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 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 A11 radio.

• If greater than 3 V

1. Ignition OFF, disconnect the X4 harness connector at the A11 radio. Ignition ON.

2. Test for less than 1 V between the signal circuit and ground.

• If 1 V or greater, repair the short to voltage on the circuit.

• If less than 1 V, replace the A11 radio.

• If between 2-3 V

10. Ignition ON.

11. Test for less than 1 V between the control circuit terminal 5 and ground.

• If greater than 1 V

1. Ignition OFF, disconnect the X4 harness connector at the A11 radio. Ignition ON.

2. Test for less than 1 V between the control circuit and ground.

• If 1 V or greater, repair the short to voltage on the circuit.

• If less than 1 V, replace the A11 radio.

• If less than 1 V

12. Ignition OFF, disconnect the X4 harness connector at the A11 radio.

13. Test for infinite resistance between the P17 info display module control circuit terminal 5 X1 and ground.

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

• If infinite resistance

14. Test for less than 2 ohms between the P17 info display module control circuit terminal 5 X1 and the A11 radio control circuit terminal 10 X4.

• If 2 ohms or greater
Repair the open/high resistance in the circuit.

• If less than 2 ohms.

15. Replace the video interface cable.

16. Connect all harness connectors.

17. Ignition ON, radio ON.

18. Verify the P17 info display module turns on and information is shown on the display.

• If the P17 info display module does not turn on, or information is not shown in the display.

1. Replace the P17 information display module.

2. Ignition ON, radio ON.

3. Verify the P17 info display module turns on and information is shown on the display.

• If the information display malfunctions, replace the A11 radio.

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

4. All OK.

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

19. All OK

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the repair.

* Driver Information Display Replacement (UAG) Driver Information Display Replacement (UAG)Driver Information Display Replacement (UDY) Driver Information Display Replacement (UDY)

* Control Module References Control Module References for radio replacement, programming, and setup.

pro multis · About Operation CHARM