P24B4

Code

Generic P — Powertrain

Particulate Matter Sensor Heater Control Circuit Range/Performance

Brand: Generic

Type: P — Powertrain

Views: UK: 24 EN: 192 RU: 40

AI status

Completed

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Page language: EN

Causes

Failed or degraded PM sensor heater element
Open, shorted or high-resistance wiring in heater supply or ground
Corroded, loose or contaminated connector(s) at the sensor or module
Blown fuse or faulty relay supplying the heater circuit
ECU/PCM/HECU driver transistor or software fault
Sensor contaminated, physically damaged or thermally degraded

Symptoms

Malfunction Indicator Lamp (MIL) or DPF warning lamp illuminated
Reduced or inhibited DPF regeneration events
DPF-related limp/derate mode on some vehicles
Stored DTC(s) related to PM/DPF system
Possible reduced fuel economy or increased soot accumulation over time

What to check

Retrieve freeze-frame and full DTC list; note driving conditions when code set
Inspect PM sensor and wiring harness for damage, corrosion, heat exposure, chafing or contamination
Visually inspect and verify fuses/relays related to heater supply
Check connector pins for corrosion, bent pins, or poor mating
Measure supply voltage to the heater harness with ignition on and compare to battery voltage
Measure continuity and resistance of heater circuit between connector and PCM; check for short to ground or short to battery

Signal parameters

Heater supply voltage (key ON/run): near battery voltage (check spec)
Heater control duty cycle or PWM: 0–100% depending on demand
Heater current draw under operation: measurable; compare to spec
Heater element resistance at ambient: low ohms (check OEM spec)
PM sensor temperature or sensor output (if available) should rise during heater activation

Diagnostic algorithm

Read and record all stored codes and freeze-frame data; clear codes and attempt to reproduce.
Visually inspect sensor, harness and connector for damage, contamination or heat exposure. Repair any obvious faults.
Verify power and ground: with ignition on, measure voltage at sensor power pin and verify good ground at ground pin.
With connector disconnected, measure heater element resistance across heater pins. Compare to OEM spec; an open or very high resistance indicates failed heater.
Reconnect and backprobe while commanding heater ON (if service tool supports) or during conditions where heater runs. Measure voltage waveform and current draw; confirm controller is driving circuit.
If supply and wiring good but no drive present, suspect ECU/HECU driver fault—confirm by checking for driver control signal from module. If driver is damaged, further module diagnosis or replacement may be required.
Repair or replace damaged wiring, terminals or sensor as indicated. After repairs, clear codes, perform relearn/regeneration procedures if required, and confirm no return of code.
If intermittent, perform extended road test or use data logger to capture failure conditions.

Likely causes

Damaged or corroded connector at PM sensor
Open or high-resistance supply/ground circuit to heater
Failed heater element inside PM sensor
Faulty heater driver in controller (ECU/HECU)

Fault status

⚠️ Status

Particulate matter sensor heater control circuit — range/performance fault detected. Heater operation outside expected parameters; may impair PM sensing and DPF regeneration control.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-3 hours