U016DLost Communication With Exhaust Gas Sensor Module B
- Generic OBD-II code · Network
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- U016D refers to exhaust gas sensor module B, a second smart sensor unit in the exhaust that heats a probe, evaluates it and reports oxygen or NOx readings as bus data instead of an analog voltage. Module A has U011A. Which sensor counts as B depends on the maker, for instance the other bank or a probe further downstream behind an SCR catalyst. No manufacturer documents U016D publicly, and the NHTSA bulletin index has no entry for it. CARB 13 CCR 1968.2 obliges OBD to flag a lost digital link from such an input with its own code, and exhaust and NOx sensors are emission monitors in their own right, so the MIL is normally lit. Mixture correction, catalyst checks or urea dosing may fall back to defaults. U046E is invalid data from module B.
- What you may notice
- Check engine light on
- Readiness monitors for catalyst or exhaust sensors not complete
- Diesel: SCR or emission warning, possibly reduced power
- Likely causes
- LikelySensor module connector or harness damaged by exhaust heat or corrosion
- PossibleSensor module without power or ground (fuse, relay)
- PossibleBus line to the module chafed under the vehicle
- PossibleSensor module B or integrated probe electronics faulty
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €60 – €900
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.