OBD-II code · Network
U011A Lost Communication With Exhaust Gas Sensor Module A
ECU lost CAN communication with exhaust gas sensor module A (often integrates wide-range O2/NOx sensors).
Is it safe to drive with U011A?
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
- Exhaust Gas Sensor Module A, Can Bus
Related codes
- U016DLost Communication With Exhaust Gas Sensor Module B
- U0117Lost Communication with Drive Motor Control Module 2
- U0118Lost Communication with Cabin Air Quality Sensor Module
- U0119Lost Communication with Steering Column Control Module
- U011BLost Communication With Rocker Arm Control Module A
- U011CLost Communication With Rocker Arm Control Module B
- U011DLost Communication With All Wheel Drive Control Module
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.