LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Ford >> 2007 >> Mustang Base, 2D Convertible, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Powertrain DTC Charts And Descriptions (Except Diesel & Hybrid) >> DTC Diagnosis >> U0121 - Lost Communication With The Anti-Lock Brake System (Abs) Control Module
April 5, 2026: LEMON Manuals is launched! Read the announcement.

U0121 - Lost Communication With The Anti-Lock Brake System (Abs) Control Module

U0121 - LOST COMMUNICATION WITH THE ANTI-LOCK BRAKE SYSTEM (ABS) CONTROL MODULE

Description:  The powertrain control module (PCM) continuously monitors the controller area network (CAN) for messages from the ABS. This DTC sets when the PCM fails to receive the ABS message within the defined amount of time.
Possible Causes: 
  • Damaged CAN communication bus circuit
Diagnostic Aids:  Network DTC concerns occur during module-to-module communication. For additional description and operation of the vehicle communication network, refer to the appropriate MODULE COMMUNICATIONS NETWORK article.
Application  Key On Engine Off  Key On Engine Running  Continuous Memory 
All -