A/C Request B Circuit
The P2522 code means the vehicle's onboard diagnostic system has detected: A/C Request B Circuit. This is a low severity code.
- Keep driving?
- Yes, but fix soon
- DIY difficulty
- moderate
- Estimated cost
- $100 - $450 (parts and labor)
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Common Symptoms
- Rear A/C not functioning
- Dual-zone climate control issues
- Check engine light on
- Front A/C works but rear does not
Probable Causes (Ranked by Likelihood)
- Faulty rear A/C request switch or module Very High
- Open circuit in B request wiring High
- Failed rear climate control module Moderate
- ECM B circuit input fault Low
Step-by-Step Diagnostic Procedure
-
Test rear A/C request switch operation
-
Check B circuit wiring for continuity from rear module to ECM
-
Inspect rear climate control module connectors
-
Verify ECM receives B request signal with scan tool
Frequently Asked Questions
What is the A/C Request B circuit?
On vehicles with dual-zone or rear A/C systems, the B circuit handles the secondary A/C request, typically from the rear climate control.
Why does only my front A/C work?
P2522 indicates the rear A/C request signal is not reaching the ECM, so the rear system cannot request compressor operation independently.
Is P2522 common on minivans and SUVs?
Yes. Vehicles with rear A/C systems have additional wiring running to the back of the vehicle, which is more susceptible to damage and connection issues.
Sources
This page is built from documented references. Verify against your own service info before repair work.
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