Diagnostic Routine AB

Diagnostic Routine AB

Diagnostic Overview

U0253:00

Normal Operation and Fault Conditions

DTC Fault Trigger Conditions






Pinpoint Test

1. VERIFY THE CUSTOMER CONCERN

1. Ignition ON.

2. Verify there is an observable symptom present.

Is an observable symptom present?








2. CHECK FOR LOST COMMUNICATION DTCs (Diagnostic Trouble Codes)

1. Ignition ON.

2. Using a scan tool, clear continuous DTCs (Diagnostic Trouble Codes) from all modules.

3. Ignition OFF.

4. Ignition ON.

5. Wait at least 10 seconds.

6. Using a scan tool, retrieve all continuous DTCs (Diagnostic Trouble Codes) from all modules.

Is DTC (Diagnostic Trouble Code) U0253:00 set in any audio system module?








3. CHECK THE AUDIO SYSTEM MODULES FOR BATTERY VOLTAGE OUT-OF-RANGE DTCs (Diagnostic Trouble Codes)

1. Using a scan tool, perform the self-test for:

- APIM (Accessory Protocol Interface Module)
- ACM (Audio Control Module)
- FCDIM (Front Control/Display Interface Module)

Are any low or high voltage DTCs (Diagnostic Trouble Codes) recorded in any module?








4. CHECK FOR DTC (Diagnostic Trouble Code) U0253:00 SET IN MULTIPLE MODULES

1. Review the recorded results from the self-test.

Is DTC (Diagnostic Trouble Code) U0253:00 set in more than one module?








5. CHECK FOR CORRECT APIM (Accessory Protocol Interface Module) OPERATION

1. Disconnect and inspect the APIM (Accessory Protocol Interface Module) connector.

2. Repair:

- corrosion (install new connector or terminals- clean module pins)
- damaged pins - install new terminals/pins
- pushed-out pins - install new pins as necessary

3. Reconnect the APIM (Accessory Protocol Interface Module) connector. Make sure it seats and latches correctly.

4. Wait 2 minutes for the APIM (Accessory Protocol Interface Module) to re-initialize.

5. Operate the system and determine if the concern is still present.

Is the concern still present?