OBD-II code · Powertrain (generic, extended)
P2522 A/C Request B Circuit
General electrical fault on the second A/C request input B. Many vehicles have two HVAC zones, a rear evaporator request, or a redundant request line — input B carries that signal. With the input invalid, the ECM cannot honour zone B compressor demand or rear-evap operation.
Is it safe to drive with P2522?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyOpen or shorted A/C request wire B
- PossibleHVAC module not transmitting request B
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Best left to a mechanic
- Typical labour
- 0.4–2 h
- Emissions test
- Usually unaffected
- Parts involved
- AC Request Input B
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.