P2258AIR System Control A Circuit High
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- P2258 reports that the line controlling secondary air (AIR) pump A or its relay sits at too high a level, usually because it is shorted to battery voltage or the driver cannot pull it down. The pump only runs briefly after a cold start to heat the catalyst faster, so the fault mainly raises warm-up emissions. GM's 2018 tables (LWE section) check it while the low-side driver is switched on: 0.5 ohm or less between signal and supply, in 20 of 25 samples of 250 ms, Type B with the MIL after two trips. VW's 2014 book for the Touareg 3.0 TSI (CGFA) gives a signal current of 0.60 to 2.40 A as criterion. Ford names P2258 beside P0412 as a secondary air fault that disables its catalyst temperature model. P2257 is the low counterpart; P2259/P2260 belong to circuit B.
- What you may notice
- MIL on, often without any noticeable change in driving
- Secondary air pump silent after a cold start
- Higher hydrocarbon emissions during warm-up, possibly a failed emissions test
- Likely causes
- LikelyControl wire of the AIR pump relay chafed through and touching a battery-voltage feed
- PossibleSecondary air relay with shorted coil or welded contacts
- PossibleMoisture or corrosion in the relay or pump connector bridging terminals
- RareFaulty output stage in the engine control module
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €30 – €400
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.