U011B
UNetworkLost Communication With Rocker Arm Module A
What does this code mean?
Severity : MediumU011B indicates lost communication with rocker arm control module A, which manages features such as variable valve lift or cylinder deactivation. This module only exists on certain engines, so the exact meaning depends on the manufacturer. Without communication, those features are usually disabled.
Symptoms
- Check engine light on.
- Loss of power or limp mode.
- Higher fuel consumption.
- Less smooth engine running.
Possible causes
- Faulty module power supply or ground.
- Blown fuse.
- Damaged CAN bus wiring or connector.
- Faulty rocker arm control module.
- Low battery voltage.
Diagnosis and repair
- Check battery voltage and module fuses.
- Measure module power and ground with a multimeter.
- Inspect network wiring and connectors.
- Test communication with the module using a scan tool.
- Repair or replace the module following the manufacturer procedure, then clear the code.
Is this vehicle in your workshop?
Upload the ORI file: it is processed automatically in a few minutes, 24/7, and a calibration engineer takes over complex cases during opening hours.
Are you a driver?
Find a garage or a diagnostics and remapping specialist near you.
Find a pro on ChiptuneMAPCode details
Code
U011B
Category
Network
Prefix
U
Standard
OBD-II / SAE J2012