Network, generic

U012C Lost Communication With Active Vibration Control Module

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

U012C covers the controller that drives active engine mounts or inertial shakers to cancel engine vibration, for example in cars that switch off cylinders. Such a unit needs engine speed and load from the network to generate a counter-phase force; a Honda patent (US 10360893) describes a separate AVC control unit with actuators and acceleration sensors that adapts its cancelling output to engine rotation. No manufacturer publishes a description of U012C itself, so the setting rule is the general one from CARB's network monitoring: the receiving controller stores the code when expected frames stay away. Engine mount actuator wiring has its own codes, P0A14 and following; invalid data is U042D. Expect more cabin vibration, usually no MIL.

Likely causes

Power or ground of the vibration control unit missing
Bus wire or connector damaged near engine or subframe
Active vibration control module internally faulty

Symptoms

  • Noticeable engine vibration at idle or in cylinder deactivation mode
  • Humming or booming noise in the cabin
  • Fuel saving mode may stay disabled

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€60–1,200
Time0.5–3 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

active vibration modulecan bus wiring

Related codes

U042DP0A14

References: law.cornell.edu, patents.google.com.