P2393: Diesel Intake Air Flow B Control Circuit High
What to do
As P2392 unless the engine has gone flat or smoky — then the P2395 picture applies and it is worth prompt attention.
What this code means
The second intake air flow valve's control circuit reads high — the mirror of P2392, with one direction worth respecting: a line stuck driving the valve can hold it closed, which is P2395's strangled-engine picture arriving electrically. Prompt if power has dropped; routine otherwise.
Likely causes
Start here
- Wiring shorted to voltage · moderate
- Open circuit in control wiring · moderate
Less common
- Control module driver failure · specialist
Symptoms
Components involved
Information, not instruction
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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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What makes one worth reading:
- The car — make, model, year and engine. The same fault behaves differently on each.
- What you measured, not only what you replaced.
- What actually fixed it — or that nothing did, which is worth knowing too.
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