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 DTC's ARE PRESENT





With the scan tool, read FCM DTCs.
Are there any FCM CAN BUS DTC's present?
Yes >> Refer to Manufacturer Code Charts / Communication . 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, dam age, or terminal push out. Pay particular attention to all power and ground circuits. If no problems are found, replace the Anti-Lock Brake Module. Perform ABS VERIFICATION TEST - VER 1. ABS Verification Test