P2521A/C Request A Circuit High
- Generic OBD-II code · Powertrain
- How the car detects it
- With P2521 the engine module sees A/C request input A held above its valid range, typically because the wire touches a supply line, the input has lost its pull-down or the sending control unit drives it permanently high. Two makers list the code by number. Ford includes P2521 in the 2014 BOSS 302S engine module table without a lamp mark. FCA's emissions recall T21 for the 2004–2006 Dodge Sprinter names P2521 among the codes that the corrected engine software may newly report after reflashing. Neither publishes a voltage limit. CARB's A/C rules apply only where the request changes fuel or spark control. P2520 is the low counterpart, P2524 the same fault on input B. Drivers notice A/C that switches on by itself, will not switch off, or ignores the button.
- What you may notice
- A/C compressor runs although A/C is switched off
- A/C button has no effect
- Raised idle speed without A/C request
- Likely causes
- LikelyRequest wire shorted to a supply voltage
- PossibleClimate control unit drives the line permanently high
- RareCode newly reported after an engine software update (Sprinter T21)
- Repair
- Medium · Usually a job for a workshop.Typical cost: €40 – €400
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.