Engine Air Filter Differential Pressure
Indicates a restriction in the engine air filter system.
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 is not getting enough air due to a clogged air filter or related component that measures the air flow.
What the computer is actually seeing
The engine control module (ECM) tracks the pressure difference before and after the air filter. If the pressure drop across the filter exceeds a set threshold, it flags this code.
What a healthy reading looks like
Normal differential pressure ranges from 0 to 3 inches H2O; over 5 inches H2O may trigger this code.
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. If it's clogged, replace it. Decision: If replaced, see if the code clears.
- 22. Inspect the air intake ducts for leaks or damage. Repair as necessary. Decision: If ducts are damaged, replace and see if the code clears.
- 33. Test the differential pressure sensor with a multimeter. It should output a voltage proportional to the pressure difference. Expected output is 0-5 volts. Decision: If out of range, replace the sensor.
Common causes
- Clogged air filter
- Damaged or leaking air intake duct
- Faulty differential pressure sensor
Typical repair cost
$$
Related codes
Frequently asked questions
Can I still drive with this code?
It's drivable, but performance may be impacted. Fix soon to avoid engine issues.
Will this code come back after clearing it?
If the underlying issue isn't resolved, yes, the code will likely return.
Why does this code pair with others?
It often indicates air flow issues, which can affect other sensors related to fuel and air mixture.
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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