P2524
A/C Request B Circuit High
A/C request / HVAC
Generic OBD-II
Low
What it means
P2524 means the ECM saw high voltage on the "B" A/C request circuit — the signal the HVAC or A/C control uses to ask the engine to engage the air-conditioning compressor. A fault here mainly affects air-conditioning operation rather than the engine itself, so the vehicle still drives normally.
Low
Can I keep driving? Yes — the engine runs normally; the fault mainly affects air-conditioning operation.
Common symptoms
What you'll notice
- Check-engine light on
- A/C not cooling or the compressor won't engage
- A/C engagement behaving erratically
- Possibly a slightly rough idle when A/C is selected
Common causes
Most likely first
- Short-to-voltage or open in the A/C request 'B' circuit wiringLikely
- Faulty A/C refrigerant pressure sensor or switchCommon
- Corroded or loose connector on the request circuitCommon
- HVAC control module faultLess often
How to diagnose & fix
Work through it in order
- Scan for codes and record freeze-frame data.
- Inspect the A/C request wiring and connectors for a short-to-power or open.
- Check the A/C refrigerant pressure sensor and its signal.
- Verify the HVAC control module's request output.
- Repair the wiring, then clear the code and re-test.
FAQ
Quick answers
Is it safe to drive with P2524?+
Yes. The engine runs normally; you may just lose reliable air conditioning until it's repaired.
Can I just clear P2524?+
It will return until the high-voltage/open in the A/C request circuit is fixed.
Related codes
Often seen with P2524
Read & clear P2524 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