DTC U0257 (With Monochrome Display)

Radio Information Display Malfunction - DTC U0257 (with Monochrome 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 Instructionsprovides an overview of each diagnostic category.

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 wake up circuit. Display backlighting dimming level, and graphical data are communicated over the data circuits.

Reference Information
Schematic Reference

Radio/Navigation System Schematics Radio/Navigation System Schematics
Connector End View Reference

Component Connector End Views Connector End Views By Name
Description and Operation

Radio/Audio System Description and Operation Radio/Audio System
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 Referencesfor scan tool information

Circuit/System Verification

1. Ignition ON, radio ON, verify the info display module turns on and information is shown on the display.

• If the info display is inoperative, refer to Circuit/System Testing.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the P17 info display module.
2. Test for less than 10 ohm between the ground circuit terminal 2 and ground.

• If greater than the specified range, test the ground for an open/high resistance.

3. Test for less than 20 ohm between the data shield circuit terminal 6 and ground.

• If greater than the specified range, test the data shield circuit for an open/high resistance. If the circuit tests normal, replace the A11 radio.

4. Verify that a test lamp illuminates between the B+ circuit terminal 1 and ground.

• If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.

5. Ignition ON, test for 2-3 V between the data circuit terminal 7 and ground.

• If less than the specified range, test the data circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the A11 radio.
• If greater than the specified range, test the data circuit for a short to voltage. If the circuit tests normal, replace the A11 radio.

6. Ignition ON, test for 2-3 V between the data circuit terminal 8 and ground.

• If less than the specified range, test the data circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the A11 radio.
• If greater than the specified range, test the data circuit for a short to voltage. If the circuit tests normal, replace the A11 radio.

7. Test for less than 1 V between the wake signal terminal 4 and ground.

• If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the A11 radio.

8. Test for less than 1 V between the reset signal terminal 5 and ground.

• If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the A11 radio.

9. Ignition OFF, reconnect the harness connector at the P17 info display module.
10. Disconnect the X1 harness connector at the A11 radio.
11. Test for 4.5-5.5 V between the signal circuit terminal 27 and ground.

• If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the P17 info display module.
• If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the P17 info display module.

12. Test for 4.5-5.5 V between the signal circuit terminal 13 and ground.

• If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the P17 info display module.
• If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the P17 info display module.

13. If all circuits test normal, replace the P17 information display module. Reconnect all harness connectors.
14. Ignition ON, radio ON, verify the info display module turns on and information is shown on the display.

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

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.

* Driver Information Display Replacement Service and Repair
* Control Module References Control Module Referencesfor radio replacement, setup, and programming