P24B6Particulate Matter Sensor Heater Control Circuit High
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- P24B6 reports the heater of the particulate matter sensor carrying current although it is commanded off, the classic sign of a battery-side short or a stuck driver stage in the sensor control unit. GM's 18OBDG04 table sets it when more than 0.2 A flows with the heater off or when the switch state disagrees with the command in one of the last five readings, Type B. GM's 14OBDG04 checks the heater voltage in the off state. VW's 2014 Touareg list names a current of 0.2 A or more. A heater that stays on can overheat and crack the ceramic element, so the sensor often has to be replaced together with the wiring repair. P24B5 covers a short to ground, P24B3 an open line, P24B4 implausible heater behaviour.
- What you may notice
- Malfunction indicator lamp on
- Particulate filter monitor does not complete
- Sensor may fail again quickly if the short is not fixed
- Likely causes
- LikelyHeater line shorted to battery voltage
- PossibleHeater output stage in the sensor control unit stuck on
- RareSensor element damaged by uncontrolled heating
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €100 – €800
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.