P2561
A/C Control Module Requested MIL Illumination
A/C control / MIL request
Generic OBD-II
Low
What it means
P2561 means the air-conditioning control module has asked the ECM to turn on the check-engine light because it detected a fault in the A/C system. It is an informational request rather than an engine fault, so the real problem — refrigerant, a pressure sensor, the compressor, or a cooling fan — is stored inside the A/C module. Reading that module's codes is the starting point for the fix.
Low
Can I keep driving? Safe to drive; the A/C control module has flagged a fault in its own system, not an engine problem.
Common symptoms
What you'll notice
- Check-engine light on
- A/C not cooling properly or compressor cycling problems
- Fault codes stored in the A/C / HVAC module
- No engine-running symptom
Common causes
Most likely first
- A/C-system fault reported by its own module (low or overcharged refrigerant)Likely
- Faulty A/C pressure sensorCommon
- Compressor, clutch, or cooling-fan faultCommon
- Communication or wiring fault between the A/C module and the ECMLess often
How to diagnose & fix
Work through it in order
- Retrieve codes from the A/C / HVAC control module — that is where the real fault sits.
- Check refrigerant charge and the A/C pressure sensor.
- Inspect the compressor clutch and cooling-fan operation.
- Check the communication wiring between the A/C module and the ECM.
- Repair the underlying A/C fault, then clear the request.
FAQ
Quick answers
Is it safe to drive with P2561?+
Yes. This code only means the A/C module asked for the warning light; the actual issue is in the A/C system, not the engine.
Can I just clear P2561?+
It returns as long as the A/C module still reports a fault. Diagnose the A/C system first.
Related codes
Often seen with P2561
Read & clear P2561 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX