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Home >> Jeep >> 2009 >> Liberty Limited, 4WD, Part Time >> Repair and Diagnosis >> Transmission >> Automatic Trans >> Powertrain Control Module (Pcm) - Electrical Diagnostics - 42RLE Automatic Transmission >> DTC Troubleshooting >> U0121-Lost Communication With Anti-Lock Brake Module >> Possible Causes

Possible Causes

Possible Causes 
DTCS RELATED TO BATTERY VOLTAGE, IGNITION, OR VIN MESSAGES
CAN C BUS CIRCUITS OPEN OR SHORTED
ABS MODULE POWER AND GROUND
ABS MODULE
POWERTRAIN CONTROL MODULE (PCM)