OBD-II code · Powertrain (generic, extended)
P24EE NH3 Sensor Processor Performance
The microcontroller inside the smart NH3 slip sensor reports an internal performance fault — failed self-test, watchdog reset, or out-of-range plausibility checks. The sensor cannot guarantee its output value, the ECM marks the channel invalid and disables SCR closed-loop control on this branch.
Is it safe to drive with P24EE?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyInternal processor or firmware fault
- PossibleBrown-out from supply voltage dips
- Less likelyModule software outdated, reflash may resolve
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Best left to a mechanic
- Typical labour
- 0.5–2 h
- Emissions test
- Likely to fail
- Parts involved
- Nh3 Sensor, Sensor Microcontroller
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.