Network & communication
Definition only
Lights the check engine lamp
U0168: Lost Communication with Vehicle Immobilizer Control Module
Standardized SAE J2012 code · U01xx — Lost communication with modules
What does U0168 mean?
The ECU cannot reach the immobilizer / vehicle security module. Engine start is usually blocked because the rolling code cannot be exchanged.
The code tells you which monitor failed, not which part is broken. Test before replacing parts.
Symptoms
- Multiple warning lights may illuminate
- Affected modules may go into limp mode or shut down
- Specific functions inoperative depending on module
- Diagnostic tools may show communication faults
Common causes
- High Immobilizer module unpowered
- Medium Wiring or antenna ring damaged
- Low Gateway module routing CAN messages incorrectly
Likelihood is a general estimate across vehicles; your make and model may differ.
Add your car to see reports of U0168 on the same make and model first.
U0168 in the community
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