OBD-II code · Network

U0168 Lost Communication with Vehicle Immobilizer Control Module

The ECU cannot reach the immobilizer / vehicle security module. Engine start is usually blocked because the rolling code cannot be exchanged.

Is it safe to drive with U0168?

The car may go into limp mode (reduced power). Get it diagnosed before a long trip.

Common causes

  • Most likelyImmobilizer module unpowered
  • PossibleWiring or antenna ring damaged
  • Less likelyGateway module routing CAN messages incorrectly

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

Repair at a glance

Difficulty
Hard
DIY friendly
Best left to a mechanic
Typical labour
0.5–4 h
Emissions test
Usually unaffected
Parts involved
Immobilizer Module, Can Bus Wiring

Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.