P24C7: Particulate Matter Sensor Temperature Circuit Range/Performance
What to do
Ask whether a heater fault from the same sensor is also stored. If it is, that is likely the real problem and this code follows from it — one repair usually clears both.
Ask for the connector to be inspected before the sensor is condemned. This sensor lives under the car in the exhaust stream, where salt and water reach it, and corrosion there causes more of these codes than element failure does.
The car will drive normally, so this is a plan-ahead repair rather than an urgent one — but the emissions self-checks will not complete while it is stored, so allow time before an MOT.
What this code means
The temperature channel of the particulate matter sensor is reporting a value that does not fit the conditions.
This sensor reports its own temperature as well as its soot measurement, and it needs to. Soot conducts differently at different temperatures, so the raw electrode reading means nothing without knowing how hot the element is — and the module also has to confirm that the self-cleaning burn actually reached temperature.
Range/performance on this channel means the value is electrically valid and contextually wrong. The usual proof is a sensor that reports a temperature far from ambient after the vehicle has stood overnight, or one that does not rise when the heater is energised.
A temperature channel that does not respond to the heater is the more interesting case, because it means one of two subsystems is faulty and they are diagnosed differently: either the heater is not heating, or the temperature element is not sensing. A heater code stored alongside settles it immediately.
Where this code stands alone with no heater fault, the sensor is the likely answer — the two functions share a housing, and a fault confined to one of them is internal.
Check the connector for high resistance first, as always on this sensor. Its location under the vehicle makes corrosion the single most common contributor to every code in the family.
Likely causes
Start here
- Faulty particulate matter sensor · moderate
- High resistance in sensor wiring · moderate
- Corroded or loose connector · easy
Less common
- Water ingress into connector · easy
- Heat damage to sensor or wiring · moderate
Symptoms
Components involved
Information, not instruction
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Community experience
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