OBD-II code · Network

U063E Lost Communication With Exhaust Heat Exchanger Bypass Valve Actuator A

The vehicle bus reports loss of communication with smart exhaust heat exchanger bypass valve actuator A. Exhaust-heat recovery cannot be commanded; cabin/coolant warm-up may slow down.

Is it safe to drive with U063E?

Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.

Common causes

  • Most likelyBus wiring open or shorted
  • PossibleModule without power or ground
  • PossibleModule failed

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
Medium
DIY friendly
Best left to a mechanic
Typical labour
0.5–3 h
Emissions test
Likely to fail
After the fix
A drive cycle is needed before the light stays off
Parts involved
Exhaust Heat Exchanger Bypass Actuator A, Vehicle Bus Wiring

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