Diagnostic Routine H

Diagnostic Routine H

Diagnostic Overview

U0121:00 or U0129

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 THE COMMUNICATION NETWORK

1. Ignition ON.

2. Using a scan tool, perform a network test.

Does the ABS (Anti-Lock Brake System) module pass the network test?








3. RETRIEVE THE RECORDED DTCs (Diagnostic Trouble Codes) FROM THE C-CM (Cruise-Control Module), ABS (Anti-Lock Brake System) MODULE AND PCM (Powertrain Control Module) SELF-TESTS

1. Using a scan tool, perform the self-test on the following modules.

- C-CM (Cruise-Control Module)
- ABS (Anti-Lock Brake System) module
- PCM (Powertrain Control Module)

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








4. RECHECK THE C-CM (Cruise-Control Module) DTCs (Diagnostic Trouble Codes)

1. NOTE: If new modules were installed prior to the DTC (Diagnostic Trouble Code) being set, the module configuration can be incorrectly set during the PMI (Programmable Module Installation) or the PMI (Programmable Module Installation) may not have been carried out.

Using a scan tool, clear the DTCs (Diagnostic Trouble Codes).

2. Repeat the C-CM (Cruise-Control Module) self-test.

Is DTC (Diagnostic Trouble Code) U0121:00 still present?








5. CHECK FOR DTC (Diagnostic Trouble Code) U0121:00 OR DTC (Diagnostic Trouble Code) U0129 SET IN OTHER MODULES

1. Using a scan tool, clear all DTCs (Diagnostic Trouble Codes).

2. Ignition OFF.

3. Wait 10 seconds.

4. Ignition ON.

5. Using a scan tool, perform Self-Test.

6. Retrieve the continuous memory DTCs (Diagnostic Trouble Codes) from all modules.

Do both the C-CM (Cruise-Control Module) set DTC (Diagnostic Trouble Code) U0121:00 and the PCM (Powertrain Control Module) set DTC (Diagnostic Trouble Code) U0129?