P24D0: Particulate Matter Sensor Supply Voltage Circuit Low
What to do
Ask whether other sensor faults are stored at the same time. This code is about the power feeding the sensor, and when several sensors share a supply, one wiring fault sets a page of codes that all clear with a single repair — so it is worth having that checked before parts are replaced one by one.
Ask for the wiring under the car to be inspected. This sensor's harness runs where road salt and water reach it, and that is the usual cause.
The car will drive normally. Plan the repair around your MOT date, since the emissions self-checks cannot complete while this is stored.
What this code means
The supply voltage feeding the particulate matter sensor is below what it needs to work.
This is a power code rather than a signal code, and that distinction should shape the diagnosis. The sensor may be entirely healthy — it is simply not being given enough voltage to operate, and every other reading it produces while starved is meaningless.
So look upstream, not at the sensor. The supply comes from the module or from a shared feed, and the causes sit along that path: a short to ground pulling the rail down, a corroded terminal dropping voltage under load, or a failed regulator inside the module.
Shared supplies are the detail worth checking first. Many vehicles feed several sensors from one regulated rail. If other sensors on that rail are also reporting low or implausible values, the fault is the supply itself rather than anything belonging to this sensor — and chasing each affected sensor in turn wastes a lot of time.
Read every stored code before starting. A page of unrelated sensor faults with one supply code among them is a supply problem, and the corpus documents that pattern repeatedly across the reference voltage family.
Where this sensor's supply is dedicated, the harness under the vehicle is the usual culprit — the same salt and water exposure that causes the rest of this family's faults.
Likely causes
Start here
- Wiring shorted to ground · moderate
- Corroded or loose connector · easy
Less common
- Shorted sensor dragging the reference down · moderate
- Water ingress into connector · easy
- Failed sensor reference voltage supply · specialist
Symptoms
Components involved
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
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