P2258–P2260 AIR System Control A Circuit High
The voltage on this circuit is sitting near battery voltage. Typically a short to a positive feed, or a disconnected sensor floating high.
Can you drive it? The engine light will stay on and the car may run in a reduced-power mode. Read the freeze-frame data to see the conditions the fault was logged under.
Which code is which
Same fault, different cylinder or bank — diagnosed the same way. Several set together usually means one shared cause.
| Code | Definition | Severity |
|---|---|---|
P2258 | AIR System Control A Circuit High | Investigate soon |
P2260 | AIR System Control B Circuit High | Investigate soon |
The definition
P2258: AIR System Control A Circuit High.
P2258 is a manufacturer-specific powertrain code (the engine or gearbox). Its meaning is set by the carmaker rather than by the SAE standard, so a generic OBD-II reader will often show it as an unknown code or misread it.
What to check first
Cheapest and fastest checks first:
- Unplug the sensor and check whether the signal falls. If it stays high, suspect the wiring rather than the sensor.
- Check the earth path - a missing earth makes a sensor read high.
What actually causes this on a VAG
This is the same secondary air injection control output as P2257 - VAG's Control 'A' circuit, which on these cars is the pump relay circuit - but reading higher than the ECU expects. That normally means an open circuit: the relay missing, unseated or with a broken feed, or a break in the control wire. It can also mean the control line is picking up voltage from something it should not be touching. The car drives exactly as normal once warm; the consequences are the warning lamp and higher emissions in the first minutes from cold.
Most likely causes, in order
- Relay missing, unseated or with a corroded socket. An open control circuit reads as high. Check the correct relay is actually fitted and pushed fully home, and inspect the socket terminals for corrosion or heat damage. A relay pulled for other work and never properly refitted is a common find and costs nothing to put right.
- Open circuit in the control wire. A broken conductor inside insulation that still looks intact is common where the loom flexes or passes heat. Follow the run from the relay carrier back towards the ECU, flexing it, and check anywhere the harness has been disturbed.
- Water damage in the pump or its connector. Secondary air components sit low and take spray. Corrosion inside the plug can leave the control line effectively open or bridged to a live pin. Unplug, inspect and dry, and look for where water is tracking down the loom into the connector.
- Chafed control wire touching a live feed. Where the loom shares a route with permanently live wiring and the insulation has worn, the control line is pulled up. Look along the run for shiny or flattened sections and anywhere a cable tie has bitten in.
- ECU output stage fault. Possible but uncommon, and only a fair conclusion once the relay, the connector and the wiring have all been proved good.
Worth knowing: If this one turns out to be water damage, fix the cause before you fit parts. The usual sequence on these systems is a combi (check) valve that has stuck or started to leak, letting hot exhaust gas and its condensate back down into the pump until the pump seizes; a pump mounted low in the arch can also ingest road spray directly. Replace a pump without checking the combi valve and the drainage around it and the new pump goes the same way.
Reading the code is the easy part
A code names the circuit that complained. What tells you why is watching the sensor behind it while the engine runs — and that is where a code reader stops and a diagnostic tool starts.
VAGPULSE reads every module in a VW, Audi, Skoda or SEAT — not just the engine — shows the live measuring blocks behind this fault, gives you the freeze-frame conditions it was logged under, and clears it once you have fixed it. It also does what a generic OBD reader cannot on a VAG: service resets, coding, adaptations, and Stage 1–3 flashing with your original file saved first.
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Common questions
What does P2258 mean?
P2258 means AIR System Control A Circuit High. The voltage on this circuit is sitting near battery voltage. Typically a short to a positive feed, or a disconnected sensor floating high.
Can I drive with P2258?
The engine light will stay on and the car may run in a reduced-power mode. Read the freeze-frame data to see the conditions the fault was logged under.