OBD-II code · Network

U0102 Lost Communication with Transfer Case Control Module

The Transfer Case Control Module has stopped transmitting on the vehicle data bus, so other control units no longer receive its messages. Four-wheel-drive range selection and torque distribution become unavailable. Typical causes are loss of power or ground at the module, an open or shorted CAN/LIN bus wire, a connector fault, or an internal module failure.

Is it safe to drive with U0102?

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

Common causes

  • Most likelyTransfer case module unpowered
  • PossibleCAN wiring to transfer case module broken
  • 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
1–6 h
Emissions test
Usually unaffected
Parts involved
Transfer Case Control Module, Can Bus Wiring

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