Lost Communication With NH3 Sensor
The vehicle bus reports loss of communication with the ammonia (NH3) slip sensor downstream of the SCR. Detection of urea over-dosing is impaired.
Affected components
- Nh3 sensor
- Vehicle bus wiring
Common causes
- High likelihood: Bus wiring open or shorted
- Medium likelihood: Module without power or ground
- Medium likelihood: Module failed
Possible 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
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
- A drive cycle may be required after repair
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.