Powertrain
generic / SAE
P24E9
NH3 Sensor Heater Circuit Performance
The heater of the NH3 slip sensor is electrically intact, but the warm-up profile or steady-state temperature feedback does not match the ECM model. The sensor takes too long to reach operating temperature or drifts away from setpoint, so SCR closed-loop control is delayed or held off.
SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number4 / E9
Possible causes
- Aged heater with increased resistance high
- Poor thermal contact between heater and sensing cell medium
Inspection / repair
- Difficulty: medium
- DIY: shop recommended
- Estimated cost: 200–950 €
- Estimated time: 0.6–2 h
- Component: nh3 sensor heater
- Component: sensor element
- MIL / check engine light
- emissions-relevant
Sources
References
sae:J2012