OBD-II code · Network
U011C Lost Communication With Rocker Arm Control Module B
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 with U011C?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyModule unpowered
- Less likelyGateway module routing CAN messages incorrectly
- Less likelyCAN terminating resistor (120 Ω) drifted out of spec
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
- 1–4 h
- Emissions test
- Likely to fail
- After the fix
- A drive cycle is needed before the light stays off
- Parts involved
- Rocker Arm Module B, Can Bus
Related codes
- U011BLost Communication With Rocker Arm Control Module A
- U0119Lost Communication with Steering Column Control Module
- U011ALost Communication With Exhaust Gas Sensor Module A
- U011DLost Communication With All Wheel Drive Control Module
- U011ELost Communication With Throttle Actuator B Control Module
- U011FLost Communication With V2X Module
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.