P24B3

Code

Generic P — Powertrain

Particulate Matter Sensor Heater Control Circuit/Open

Brand: Generic

Type: P — Powertrain

Views: UK: 40 EN: 196 RU: 43

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Retrieve P24B3 and any linked codes and review freeze-frame / live data
Perform a visual inspection of the PM sensor, wiring harness, and connector for damage, corrosion or heat exposure
Check relevant fuses and relays for the sensor heater circuit
Measure heater element resistance with the sensor disconnected (ignition OFF)
Backprobe the sensor connector with ignition ON and command heater ON using a scan tool to verify supply and control signals
Check continuity from ECM connector pin to sensor connector pin and for shorts to ground or battery

Heater supply voltage: approximately battery voltage (~11–14 V) when heater supply is present
Heater resistance (typical): low ohm range — commonly around 0.5–20 Ω (refer to vehicle-specific spec)
Control signal: ECM may use switched supply or PWM duty control (0–100% duty cycle) to regulate heater current
Current draw when heater energized: up to several amps depending on design (measure with clamp meter if required)

Confirm the active/stored status of P24B3 with a scan tool and note freeze-frame/livedata. Check for related DPF or sensor codes.
Perform a careful visual inspection of the PM sensor, connector, and wiring for heat damage, chafing, or corrosion. Repair obvious damage.
With ignition OFF, disconnect the PM sensor connector and measure resistance across the heater terminals. Infinite/open = internal heater fault (replace sensor). Very high resistance compared to spec = replace sensor.
Check applicable fuse(s) and relay(s) for the heater supply. Replace if blown/faulty and retest.
With ignition ON (engine OFF) use a scan tool to command the heater ON. Backprobe the connector: verify battery/supply voltage at the supply terminal and verify the control/ground terminal shows ECM command (switching or pulled to ground depending on design).
If supply is present but no control signal, check continuity between ECM and sensor connector for the control circuit. If control wiring open/shorted, repair wiring and re-test.
If control signal is present and wiring good but heater shows open or abnormal resistance, replace the PM sensor.
If wiring and sensor check good but there is no proper control signal or expected current draw, suspect ECM driver fault and consult manufacturer guidance before replacing ECM.
After repairs, clear codes, perform a forced regeneration or drive cycle as required, and confirm code does not return.