P2523
A/C Request B Circuit Low
A/C request circuit
Generic OBD-II
Low
What it means
P2523 means the second ("B") air-conditioning request circuit — the signal that tells the engine controller the A/C is calling for the compressor — is reading low, usually a short to ground or lost signal. It doesn't affect how the engine runs; the practical symptom is that the A/C may not engage or the idle won't rise to support it.
Low
Can I keep driving? Yes — this is the air-conditioning request signal, so the engine runs fine; you may just find the A/C or its idle-up behavior doesn't work correctly.
Common symptoms
What you'll notice
- Check-engine light on
- A/C may not engage or fails to cool
- Engine may not idle up when A/C is requested
- No serious effect on how the car drives
Common causes
Most likely first
- Short to ground or low voltage on the A/C request 'B' circuitLikely
- Faulty A/C pressure switch or request sensorCommon
- Damaged wiring or connectorCommon
- Poor or corroded electrical connectionLess often
- HVAC or body control module faultLess often
How to diagnose & fix
Work through it in order
- Read freeze-frame data to see when the fault set.
- Inspect the A/C request 'B' circuit wiring and connector for shorts or corrosion.
- Watch the request signal with the A/C switched on and off.
- Test the A/C pressure switch or request sensor.
- Repair the wiring or replace the faulty component, then clear and re-test.
FAQ
Quick answers
Is it safe to drive with P2523?+
Yes — this is the A/C request signal, not an engine-control fault. At worst the air conditioning won't work correctly; the car drives normally.
Can I just clear P2523?+
It returns once the module re-checks the circuit unless the wiring, connector, switch, or sensor is repaired.
Related codes
Often seen with P2523
Read & clear P2523 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