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 diagnosis 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