U Code Charts

U1147-1 Check The Anti-Theft Indicator For Proper Operation
- Start the vehicle.
- Verify the theft indicator proves out properly.
Does the vehicle start with the theft indicator flashing?
Yes
- If the vehicle starts, VERIFY the PCM calibration is correct for the vehicle.
- If OK, Refer to Powertrain Management diagnosis by symptom. Testing and Inspection
No
Go to U1147-2.

U1147-2 Check the PCM diagnostic capability
- Connect NGS to DLC.
- Retrieve and document continuous DTCs.
- Clear continuous DTCs.
- PCM Self-Test.
Does the NGS communicate with the PCM?
Yes
GO to U1147-3.
No
Refer to the Multiplex Communication Network. Testing and Inspection

U1147-3 Retrieve The PCM DTCs
- Retrieve and document continuous DTCs.
Is DTC P1260 retrieved?
Yes
GO to U1147-4.
No
- VERIFY PCM power and ground.
- REPLACE the Passive Anti-Theft System (PATS) Control Module. Service and Repair
- CYCLE the ignition to RUN using two encoded ignition keys.
- Go to Pinpoint Test B2139. B2139: PCM ID Does Not Match Between PATS and PCM
- CLEAR the DTCs.
- TEST the system for normal operation.
- If DTC U1147 still exists, REPLACE the PCM. Procedures

U1147-4 Check The Communication Network
- Repeat Inspection and Verification steps 4 through 8. Initial Inspection and Diagnostic Overview
- Key OFF.
- Retrieve and document continuous DTCs.
- Clear continuous DTCs.
- Perform PATS on-demand self-test.
Is DTC U1147 retrieved?
Yes
- REPLACE the Passive Anti-Theft System (PATS) Control Module.
- CYCLE the ignition to RUN using two encoded ignition keys.
- Go to Pinpoint Test B2139. B2139: PCM ID Does Not Match Between PATS and PCM
- CLEAR the DTCs.
- TEST the system for normal operation.
- If DTC U1147 still exists, REPLACE the PCM. Procedures
No
System is OK.