P2522 is the general circuit code for a second wired A/C request input, B. Why an engine module would need two such lines is left to each maker; plausible uses are a separate rear evaporator, a second request stage or a redundant line to cross-check input A. The common purpose stays the same: the module must learn of the coming compressor load in time to adjust idle and torque. CARB has required monitoring of electronic A/C components since the 2006–2008 phase-in, provided switching the A/C alters fuel or spark control. In networked systems, such as the 2011 Saab 9-5 that receives its A/C request as a CAN message, no such wire exists. No maker documents P2522 publicly. P2523 and P2524 denote low and high levels on B, P2519 the fault on input A.
Low severity. Can I keep driving?Yes, you can keep driving. The air conditioning may not work.
Symptoms
- A/C function served by input B unavailable
- Idle dips when the compressor engages without notice
Most likely causes
- Input B wire broken or connector loose
- Sending climate module or switch faulty
- Engine module input stage faulty
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- Repair difficulty: medium
What each character of P2522 means
- P: Powertrain: engine and transmission
- 2: Generic code: same on every make
- 5: Speed and idle
- 22: Specific fault in that system
Frequently asked questions
Can I keep driving with code P2522?
Yes, you can keep driving. The air conditioning may not work.
What causes code P2522?
The most common causes are: input B wire broken or connector loose; sending climate module or switch faulty; engine module input stage faulty.
Related codes
Sources
Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.