OBD-II code · Powertrain (generic, extended)
P2520 A/C Request A Circuit Low
The A/C compressor request input A reads stuck low — typically a short to ground or a permanently asserted request. The ECM either sees A/C demanded all the time (cannot release idle-up, raises fuel use) or cannot distinguish a real request from the stuck low level.
Is it safe to drive with P2520?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyRequest wire shorted to ground
- Less likelyConnector pins corroded - high contact resistance
- Less likelyHarness chafing through insulation
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 A
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.