P2677: Air Cleaner Inlet Control Circuit High
What to do
Probably nothing to feel, and nothing at risk.
Two cheap things to check before anything is bought. First, if the air filter has been changed recently, the actuator's connector may simply have been left unplugged — free to fix. Second, ask whether the warm-air duct is still there: a tube runs from the airbox down to a shroud near the exhaust manifold, it lives in the hottest part of the engine bay, and on older cars it perishes and falls off unnoticed. Nothing draws attention to its absence, and it costs a fraction of what the actuator does.
Worth sorting before an emissions test, since the monitor will not complete.
What this code means
The air cleaner inlet control circuit reads above its valid range — an open circuit, a disconnected connector, or a short to supply.
The flap's purpose is described at P2675, and the airbox-servicing point at P2676 applies here even more directly: an open circuit is exactly what a connector left unplugged after a filter change produces.
One cause specific to this part is worth naming, because it is not electrical at all and it is easy to overlook. The warm-air side of this system draws through a duct — usually a flexible or moulded tube running down to a shroud around the exhaust manifold. That duct lives in the hottest, most vibrated part of the engine bay, and it perishes, cracks and falls off. Once it is gone the flap can move perfectly and select a source that is no longer connected to anything, so the module sees a mechanism that responds to commands while the intake air temperature never changes as expected.
A missing warm-air duct is common on older vehicles precisely because it is invisible: nothing about it is on a service schedule, it is out of sight beneath the airbox, and its absence causes no noise and no leak. Worth a look before anything is replaced, since the duct is a fraction of the price of the actuator.
Driveability consequences remain minor.
Likely causes
Start here
- Disconnected sensor connector · easy
- Open circuit in module wiring · moderate
- Faulty air cleaner inlet actuator · easy
- Missing or perished warm air duct · easy
Less common
- Wiring shorted to voltage · moderate
Symptoms
Components involved
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
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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