P24C7

Code

Generic P — Powertrain

Particulate Matter Sensor Temperature Circuit Range/performance

Brand: Generic

Type: P — Powertrain

Views: UK: 37 EN: 733 RU: 114

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Page language: EN

Causes

Open or short in the PM sensor temperature wiring (to power, ground, or another circuit)
Corroded, loose, or damaged connector at the PM sensor
Failed (out-of-spec) particulate matter temperature sensor (thermistor)
Poor or missing sensor ground or supply voltage
Contamination or physical damage to the sensor (soot, deposits, heat damage)
Faulty ECU/PCM input circuit (less common)

Symptoms

Malfunction Indicator Light (MIL) / Check Engine Light illuminated
Stored P24C7 (manufacturer-specific) and possibly related DPF/aftertreatment codes
DPF regeneration inhibited or abnormal regen behavior
Incorrect PM temperature readings visible on a scan tool (out-of-range or erratic)
Possible limp-home strategy or reduced emissions control performance

What to check

Retrieve freeze frame and live data with a scan tool; confirm PM sensor temperature PID behavior
Visual inspection of sensor harness and connector for damage, corrosion, soot, or heat exposure
Check for other DPF/aftertreatment codes that may indicate related faults
Confirm vehicle battery voltage and relevant fuses/power supplies to the sensor circuit
Wiggle test harness/connectors while watching live PID for intermittent changes

Signal parameters

Sensor type: typically an NTC thermistor in PM sensor (ECU measures voltage or resistance)
Typical ECU sensor circuit voltage range: ~0.1–4.9 V (varies by manufacturer)
Expected ambient temperature voltage often in the ~1–3 V range at ~20–25°C (vehicle-specific)
Open-circuit indication: very high voltage or no change; short-to-ground: near 0 V; short-to-power: near battery voltage
Resistance vs. temperature follows NTC curve — compare measured resistance to sensor chart/spec

Diagnostic algorithm

Connect a capable scan tool. Record freeze frame, current PIDs for PM sensor temperature, and related DPF codes.
Perform a visual inspection of the PM sensor, wiring harness, and connector for heat damage, soot, corrosion, or physical damage.
With ignition ON (engine off), backprobe the sensor connector. Verify reference supply and ground at the connector (compare to battery voltage and chassis ground).
Measure sensor signal voltage with ignition ON and note value. Compare live PID to direct voltage reading.
Measure sensor resistance with the sensor disconnected (engine cool) and compare to the manufacturer thermistor chart. Heat the sensor slowly (hot water or heat gun carefully) to verify resistance changes with temperature.
Check for shorts to power or ground: measure continuity from signal wire to battery positive and to ground.
If intermittent, perform wiggle and stress tests on harness while monitoring live data for dropouts or spikes.
If wiring/connector faults are found, repair/replace damaged wiring or connector and retest. Use dielectric grease after repair if appropriate to prevent corrosion.
If wiring checks OK and sensor resistance/voltage out of spec, replace the PM temperature sensor and retest.
If sensor and wiring good but issue persists, investigate ECU input circuit or perform ECU replacement only after confirming external circuitry is functional.
Clear codes, perform a drive or regen cycle as required, and verify the fault does not return.

Likely causes

Broken wire or chafed insulation near harness rub points or exhaust heat exposure
Water intrusion/corrosion at the sensor connector
Thermistor element failed due to soot or overheating
Connector pins pushed back or bent preventing contact
Aftertreatment work or replacement with incorrect/defective sensor

Fault status

⚠️ Status

Particulate Matter Sensor Temperature Circuit Range/Performance — sensor voltage or resistance is outside expected range or inconsistent, indicating possible open/short/damaged sensor or wiring fault.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2.5 hours