Air Filter Differential Pressure
Indicates a problem with the air filter's differential pressure sensor.
Heads up: this code wasn't in our hand-written library yet, so DiagCoach AI built this page on the fly. Double-check critical specs against service info before condemning parts.
What it means (plain English)
The engine's computer is getting weird readings from the air filter pressure sensor, indicating the filter might be clogged or there's a sensor issue.
What the computer is actually seeing
The ECM monitors the pressure before and after the air filter. A significant difference indicates either high restriction due to dirt or a faulty sensor.
What a healthy reading looks like
Typically, the pressure difference should not exceed 5 inches of water column on a properly functioning filter.
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.
- 11. Check the air filter for dirt and restrictions. Replace if heavily clogged.
- 22. Inspect the wiring and connectors to the differential pressure sensor for damage or corrosion.
- 33. Measure the voltage signal from the differential pressure sensor. Expected voltage should be between 0.5 to 4.5 volts depending on the system's design.
- 44. If the sensor voltage is out of range, replace the differential pressure sensor.
- 55. Clear the code and test drive the vehicle to see if the code returns.
Common causes
- Clogged air filter
- Faulty differential pressure sensor
- Wiring issues to the sensor
- Air intake leaks
Typical repair cost
$$
Related codes
Frequently asked questions
Can I drive with this code present?
It's drivable, but you may notice reduced engine performance. Fix it soon.
Will this code come back after clearing?
If the issue is not resolved, yes, it will return.
Why might this code show up alongside other SPN codes?
It often pairs with codes related to air intake or filter conditions, as these systems interact.
Working a real vehicle right now?
Let DiagCoach walk you through it live with your specific symptoms, vehicle, and what you've already checked.
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