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Home >> Chrysler >> 2005 >> 300 Base >> Repair and Diagnosis >> External Pages >> Different car >> Section 363 (Electronic Control Modules - Electrical Diagnostics) >> Electronic Control Modules - Electrical Diagnostics >> DTC Troubleshooting >> U0121-Lost Communication With Anti-Lock Brake System (Abs) Control Module >> Possible Causes
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Possible Causes

WARNING: This page is about a different car, the 2005 Dodge Durango. However, it is still accessible from the selected car via links, so may be relevant.
Possible Causes 
CAN B OR CAN C BUS CIRCUITS OPEN OR SHORTED
DTCS RELATED TO BATTERY VOLTAGE, IGNITION, OR VIN MESSAGES
FCM NOT CONFIGURED CORRECTLY
ANTILOCK BRAKE MODULE
ANTILOCK BRAKE MODULE POWER AND GROUND
MODULE THAT SET THIS DTC