• 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.

Refer to Control Module U Code List.

Some devices must be configured with specific software, serial numbers, vehicle options, or other information. If a device was not properly configured after installation that device may set the appropriate communication DTCs. No external circuit diagnosis is involved.

Battery voltage is between 9–16 V and data link communications operate normally.

The device is not configured properly.

• A current DTC clears when the malfunction is no longer present.
• A history DTC clears when the device ignition cycle counter reaches the reset threshold, without a repeat of the malfunction.

• Data Communication Schematics
• Control Module References

Master Electrical Component List

Data Link Communications Description and Operation

• Circuit Testing
• Connector Repairs
• Testing for Intermittent Conditions and Poor Connections
• Wiring Repairs

Control Module References for scan tool information

1. Ignition ON/Vehicle In Service Mode.
2. Verify DTC U0300-U0336 is not set.
• If DTC U0300-U0336 is set
1. Program the device specified by the DTC descriptor.
2. Verify the DTC does not set.
• If the DTC sets, replace the device specified by the DTC descriptor.
• If the DTC does not set
3. All OK.
• If DTC U0300-U0336 is not set
3. All OK

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for device replacement, programming and setup