P24B5 code meaning
Particulate Matter Sensor Heater Control Circuit Low
Powertrain system Generic code P24xx codes Check engine light
What P24B5 means
P24B5 points to the heater line of the particulate matter sensor being pulled toward ground, so the heater control sees an implausible current while heating is requested. GM's 18OBDG04 table describes it as a ground fault on the heater line and flags it when current is under 0.5 A or above 15 A with the heater commanded on, 30 of 60 samples, Type B with two trips. VW's 2014 Touareg list uses a heater current below 1 A or above 15 A. GM issued PIP5607 for 2019 Silverado and Sierra 2500/3500 with the 6.6L L5P, telling technicians to clear P24B3 or P24B5 because engineering suspected false setting. While the heater cannot work, the sensor cannot clean itself and the filter monitor stops. P24B3 is the open circuit, P24B6 the short to power.
P24B5 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium, DIY possible
- Typical labor0.5 to 2 hours
- Clears after repairAfter a drive cycle
Symptoms of P24B5
- Malfunction indicator lamp on
- Particulate filter monitor does not complete
Common causes of P24B5
- Most likelyHeater line shorted to ground
- PossibleInternal heater fault in the sensor
- Less likelyFalse detection by the control software
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Particulate matter sensor heater
What each part of P24B5 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 4 | Area: auxiliary emission controls (catalytic converter, EGR, EVAP). |
| B5 | The exact fault in that area. |
What to do next
- Note P24B5 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P24B5
What does P24B5 mean?
P24B5 means "Particulate Matter Sensor Heater Control Circuit Low". P24B5 points to the heater line of the particulate matter sensor being pulled toward ground, so the heater control sees an implausible current while heating is requested. It is a generic code, so it means the same on every make.
Is it safe to drive with P24B5?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P24B5 fail an emissions test?
Yes, it can. P24B5 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P24B5 to fix?
Difficulty: medium. A typical repair takes 0.5 to 2 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P24B5 clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.