Diagnostic article Generic OBD-II
P24B5: particulate sensor heater reports a ground-short condition
P24B5 evaluates heater current and fault events while the particulate sensor heater is commanded on.
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Documented application
2025 GM 25OBDG04B diagnostic parameter file; the cited monitor is documented, but individual vehicle, engine and calibration applicability has not been established.
The code alone does not identify a failed part or establish that a vehicle is safe to drive. Confirm the vehicle, reporting module and applicable service procedure.
P24B5 is the low heater-control code for the particulate sensor. The source describes a short to ground on the heater line, evaluated inside the sensor control unit while heater duty cycle is greater than zero.
The failure uses more than a low voltage
The listed current criteria are below 0.5 A or above 15 A. The table also includes a ground-short error-event count above 100. These are internal diagnostic quantities; the generic circuit-low name should not be reduced to one guessed terminal-voltage test.
ECM qualification requires the bus relay on, no relay fault, no lost sensor communication and no control-unit undervoltage fault. The reporting counter is nine consecutive failures or nine out of 32 samples on a 100 ms task, with Type B, two trips.
What to establish next
Keep heater command and current or fault-event status together. A heater-off observation cannot test the on-state criterion. Also distinguish the particulate sensor's own heater from the exhaust heating used for filter regeneration.
For verification, the heater must enter an eligible commanded-on state and complete the relevant electrical check without the ground-short report. The summary identifies the failure category but does not establish the physical short location or authorize applying power directly to the sensor. Follow the vehicle-specific electrical procedure to determine the remedy.
Source and application limits
This explanation covers the cited 2025 GM monitor. Confirm the vehicle and calibration in its service information before applying these limits; inclusion in this file does not establish model compatibility. GM diagnostic parameters, PDF page 1494.
Article source documents
Source checks describe how the text was prepared; they do not certify a diagnosis or confirm compatibility with every vehicle using this code.
Original code reference
Dictionary definition
Particulate Matter Sensor Heater Control Circuit Low
This definition retains its original catalog scope. The article above is limited to its explicitly documented application.
Reference scope
Generic OBD-II definition.
A manufacturer label does not establish the model, year, engine or module to which a diagnosis applies. Read the safety and diagnostic limits.
Definition source
- DTC Database: pinned community code definitions
Source checked · MIT