U011C

What it means

ECU lost CAN communication with rocker arm control module B (variable valve actuation). A communication loss with this module breaks any function relying on its data — diagnostic tools may show 'no response' and dependent modules can fall into limp mode.

Is it safe to drive?

The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical.

Most likely causes

• Module unpowered

  high

  One of the most commonly reported causes for this code — check this first.

• Gateway module routing CAN messages incorrectly

  low

  Less common, but worth ruling out after the more likely causes.

• CAN terminating resistor (120 Ω) drifted out of spec

  low

  Less common, but worth ruling out after the more likely causes.

Related help

• Full U011C diagnosis, causes & costs
• How to read check engine light codes
• Is it safe to drive with the light on?