P24E6NH3 Sensor Heater Circuit/Open
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- Like a NOx sensor, the ammonia sensor only measures once its ceramic element is hot, so it carries an electric heater. P24E6 reports that this heater circuit is open or otherwise electrically faulty: the driver commands heating but sees no current flowing. Common reasons are a burnt heater element, a broken wire in the pigtail or a terminal that lost contact. Without heat the probe stays cold and delivers no usable ammonia value, so dosing runs on the model alone. No manufacturer documents P24E6 publicly. CARB's heavy-duty rule requires a malfunction when heater current or voltage drop leaves the specified window. Low and high faults are P24E7 and P24E8; slow or unstable heating is P24E9.
- What you may notice
- Check engine light on
- No ammonia reading after warm-up
- Likely causes
- LikelyHeater element inside the NH3 probe burnt through
- PossibleBroken wire in the sensor pigtail near the hot exhaust
- RareHeater terminal without contact in the connector
- 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: €250 – €1,400
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.