OBD-II code · Powertrain (generic, extended)
P24B4 Particulate Matter Sensor Heater Control Circuit Range or Performance
Same as P24B3 with the heater control loop in plausible range yet not matching the heater model. The sensor heater warms the element to operating temperature (~600 °C); without it the lambda sensor stays inactive in closed loop and the ECM cannot trim mixture.
Is it safe to drive with P24B4?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyHeater element aged
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
- Particulate Matter Sensor Heater
Related codes
- P24B1Particulate Matter Sensor Circuit High
- P24B2Particulate Matter Sensor Circuit Intermittent
- P24B3Particulate Matter Sensor Heater Control Circuit Open
- P24B5Particulate Matter Sensor Heater Control Circuit Low
- P24B6Particulate Matter Sensor Heater Control Circuit High
- P24B7Particulate Matter Sensor Heater Resistance
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.