Diesel Particulate Filter Pressure Sensor Low Input
Indicates low voltage or signal from the DPF pressure sensor.
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What it means (plain English)
The DPF pressure sensor is supposed to read the pressure before and after the Diesel Particulate Filter. If it sees too low a signal, it tells the ECU something's wrong, usually that the sensor is faulty or there's a wiring issue.
What the computer is actually seeing
The DPF pressure sensor provides a voltage signal that varies with pressure. A healthy sensor typically sends out 0.5V at low pressure (before the filter) to about 4.5V at high pressure (after the filter). If the ECU reads a voltage below 0.1V or above 4.8V, it triggers this code.
What a healthy reading looks like
Normal operation should see a sensor voltage between 0.5V (low pressure) to 4.5V (high pressure) under various loads.
Guided diagnostic — the DiagCoach way
Don't just throw parts at it. Walk through these in order — each step tells you whether to keep going or stop and fix what you found.
- 1Check wiring and connectors to the DPF pressure sensor for damage or corrosion. Decision: If damaged, repair or replace. If not, proceed to the next step.
- 2Measure the voltage at the DPF pressure sensor connector with the key on (engine off). Expected: Should be around 0.5V or higher. Decision: If voltage is too low (<0.1V), suspect the sensor. If normal, look for a possible clogged DPF.
- 3Run the engine at idle and measure the pressure readings from the DPF. Expect steady readings without wild fluctuations. Decision: If readings are erratic, replace the sensor. If steady, assess the DPF condition.
Common causes
- Faulty DPF pressure sensor
- Wiring issues (frayed or shorted wires)
- Connector corrosion
- Clogged DPF leading to erroneous pressure readings
Typical repair cost
$$$
Related codes
Frequently asked questions
Is it safe to drive with this code?
It depends on the symptom. If the DPF is functioning fine, you may continue driving but will eventually need to fix it to avoid further damage.
Could this code return after repairs?
Yes, if the underlying issue isn't fixed or if there's still a fault in wiring or connectors.
Why does it pair with P2002?
P2002 indicates a DPF efficiency problem, which can be related to improper pressure readings from the pressure sensor.
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