What it means
The barometric pressure and turbocharger/supercharger boost sensor A readings do not correlate as expected.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
The barometric pressure sensor reports ambient air pressure, while turbocharger or supercharger boost sensor A reports pressure in the forced-induction system. The control module compares these readings and sets P00CF when sensor A's boost reading does not correlate with barometric pressure as expected.
Common causes
Most likely first.
- Barometric pressure sensor reading inaccurately
- Boost pressure sensor A reading inaccurately
- Loose, corroded, or damaged sensor connector
- Open or shorted sensor wiring
Symptoms
- Check engine light on
- Significant power loss / limp mode
- Possible blue or black smoke from exhaust
- Whistling or hissing sound from intake
How to diagnose it
- Record freeze-frame data and compare barometric pressure with boost sensor A readings at key-on and during operation to see when they diverge.
- Inspect boost sensor A and barometric pressure sensor connectors and wiring for corrosion, looseness, damaged insulation, or shorts.
- Check intake and charge-air plumbing for loose connections, leaks, or damage that could explain the reported boost behavior.
- Compare sensor A and barometric pressure readings with other available pressure data under the same conditions.
- Test both sensors and their circuits against the manufacturer's specification to determine whether the mismatch comes from a sensor or its wiring.
Common fixes
- Reconnect or repair a loose, corroded, or damaged boost sensor A or barometric sensor connector.
- Repair open, shorted, or damaged wiring in either sensor circuit.
- Repair a confirmed leak or loose connection in the intake or charge-air plumbing.
- Replace the pressure sensor that fails testing.
Can I keep driving?
Avoid hard acceleration, towing, and sustained boost until the fault is diagnosed; reduced power or limp mode can make merging and passing difficult. Stop if power loss is severe, smoke increases, or the intake makes a new whistling or hissing noise.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.