OBD-II code · Powertrain (generic, extended)
P24E1 NH3 Sensor Circuit
A general circuit fault on the NH3 (ammonia) sensor - measures ammonia slip downstream of the SCR catalyst to detect AdBlue overdose.
Is it safe to drive with P24E1?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyOpen in sensor or wiring
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Best left to a mechanic
- Typical labour
- 1–3 h
- Emissions test
- Likely to fail
- Parts involved
- Nh3 Sensor
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.