U1501–IMPLAUSIBLE MESSAGE DATA LENGTH RECEIVED FROM ECM/PCM

For a complete wiring diagram Refer to Section 8W


  • When Monitored:

    Continuously, with ignition on.

  • Set Condition:

    If the Anti-Lock Brakes Module detects bus messages from the Engine Control Module (ECM) or Powertrain Control Module (PCM) are of improper data length.


Possible Causes
 
WIRING HARNESS, TERMINAL, CONNECTOR DAMAGE
 
DTCs RELATED TO BATTERY VOLTAGE, IGNITION, OR VIN MESSAGES
 
CAN C BUS CIRCUITS OPEN OR SHORTED
 
ECM OR PCM DTCs PRESENT
 
ECM OR PCM
 
ANTI-LOCK BRAKES MODULE
 




Diagnostic Test

1.VERIFY DTC IS ACTIVE








Does this DTC reset?

Yes
  • Go To 2


No
  • The condition that caused the symptom is currently not present. Inspect the related wiring for a possible intermittent condition. Look for any chafed, pierced, pinched, or partially broken wires.
  • Refer to the ABS-INTERMITTENT CONDITION TEST. (Refer to 5 - BRAKES - DIAGNOSIS AND TESTING)

2.CHECK FOR ANY OF THE FOLLOWING ACTIVE DTCs


NOTE: Check for CAN C hardware electrical, VIN Missing/Mismatch, battery or ignition related DTCs.



Does the scan tool display any active DTCs related to the conditions listed above?

Yes
  • Diagnose and repair the DTC(s). Refer to the Table of Contents in the applicable Section.


No
  • Go To 3

3.CHECK IF ECM OR PCM DTCs ARE PRESENT



Are any DTCs present?

Yes


No
  • Go To 4

4.CHECK FOR ADDITIONAL COMMUNICATION RELATED DTCs



Is there more than one module with active DTCs “Logged Against” the ECM or PCM?

Yes
  • Replace/update the ECM or PCM in accordance with the service information.
  • Perform POWERTRAIN VERIFICATION TEST. Refer to 9 - ENGINE - DIAGNOSIS AND TESTING.
  • Perform ABS VERIFICATION TEST. (Refer to 5 - BRAKES - STANDARD PROCEDURE).


No
  • Using the schematics as a guide, check the Anti-Lock Brakes Module pins, terminals, and connectors for corrosion, damage, and terminal push out. Pay particular attention to all Communication circuits. If no problems are found, replace the Anti-Lock Brakes Module in accordance with the Service Information.
  • Perform ABS VERIFICATION TEST. (Refer to 5 - BRAKES - STANDARD PROCEDURE).