U0401

U0401 -IMPLAUSIBLE DATA RECEIVED FROM ECM/PCM





For the Anti-Lock Brake System circuit diagram. Refer to SCHEMATICS AND DIAGRAMS.

When Monitored
Continuously with the ignition on, one valid CAN message received at least once, and no U0002-CAN C Bus Off Performance DTC present.

Set Condition
When the Anti-Lock Brake Module detects an incorrect CAN message from the Engine Control Module (ECM).

Possible Causes
- FCM CAN BUS DTCS
- ENGINE DTCS
- ANTI-LOCK BRAKE MODULE

Diagnostic Test
1. CHECK IF FCM CAN BUS DTC'S ARE PRESENT





With the scan tool, read FCM DTCs.

Are there any FCM CAN BUS DTCs present?
Yes >> Refer to 8-ELECTRICAL/ELECTRONIC CONTROL MODULES - DIAGNOSIS AND TESTING and diagnose the appropriate symptom.
Perform ABS VERIFICATION TEST - VER 1. ABS Verification Test
No >> Go To 2
2. CHECK IF ENGINE DTC'S ARE PRESENT





With the scan tool, read Engine DTCs.

Are there any Engine DTCs present?
Yes >> Refer to the 9 - ENGINE ELECTRICAL DIAGNOSTICS and diagnose the appropriate symptom.
Perform ABS VERIFICATION TEST - VER 1. ABS Verification Test
No >> Using the schematics as a guide, check the Anti-Lock Brake Module pins, terminals, and connectors for corrosion, damage, or terminal push out. Pay particular attention to all power and ground circuits. If no problems are found, replace the Anti-Lock Brake Module per the Service Information.
Perform ABS VERIFICATION TEST - VER 1. ABS Verification Test