U1503

U1503-IMPLAUSIBLE MESSAGE DATA LENGTH RECEIVED FROM FCM

- When Monitored:
Continuously with the ignition on.
- Set Condition:
When the Anti-Lock Brake Module detects an incorrect CAN message from the Front Control Module (FCM).

Possible Causes
FCM CAN BUS DTCS
ANTI-LOCK BRAKE MODULE

Diagnostic Test
1. CHECK IF FCM CAN BUS DTCs ARE PRESENT
With the scan tool, read FCM DTCs.
Are there any FCM CAN BUS DTCs present?
Yes >>
Refer to Body Control Systems and diagnose the appropriate symptom.
Perform ABS VERIFICATION TEST - VER 1. ABS Verification Test
No >>
Replace the Anti-Lock Brakes Module.
Perform ABS VERIFICATION TEST - VER 1. ABS Verification Test