P255F
- Powertrain
- Manufacturer-specific
Diagnose soon
Usually safe to drive short distances, but the fault will not clear itself and can worsen or fail an emissions test.
A/C Request A Circuit Range/Performance
This code is in our catalogue but has not yet been through editorial review, so the guidance below is limited to what our structured data supports. We publish deeper diagnostic content only after a code has been reviewed — here is why.
The A/C request input A is electrically intact, but its value does not match the system context — for example asserted while the HVAC controller reports off, toggling rapidly, or sustained while compressor pressures cannot support it. The ECM disables A/C clutch engagement until the input becomes plausible.
A trouble code records what a control module measured. It does not identify which part failed. Test before replacing anything.
- Safe to drive
- Usually safe to drive short distances, but the fault will not clear itself and can worsen or fail an emissions test.
- Urgency
- Diagnose soon
- Will it pass emissions
- Not affected
- Check engine light
- Solid
| # | Cause | How often | Component |
|---|---|---|---|
| 1 | HVAC module sending inconsistent request | Very common | — |
| 2 | Sensor element aged beyond calibration window | Occasional | — |
| 3 | Sensor mounting loose - signal damping | Occasional | — |
Ordering reflects how often each cause is responsible in general, not a probability for your vehicle. Confirm by testing.
- Ac Request Input A
- HVAC Module
- Definition
- Generic code set (SAE J2012 / ISO 15031-6) via the OBDexopen database, dedicated to the public domain under CC0-1.0.
- Diagnostic guidance
- Written and reviewed in-house. See our editorial policy.
- Review status
- Awaiting review
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