OBD-II code · Powertrain (generic, extended)
P2257 Secondary Air Injection System Control A Circuit Low
The control circuit of the secondary air injection system A reads a voltage below specification. Either the relay output is shorted to ground or the wiring/load is faulty.
Is it safe to drive with P2257?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyControl wire shorted to ground
- PossibleFaulty SAI relay
- Less likelyConnector pins corroded - high contact resistance
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.5–2 h
- Emissions test
- Likely to fail
- After the fix
- A drive cycle is needed before the light stays off
- Parts involved
- Secondary Air Pump, Sai Relay, Sai Wiring
Related codes
- P2259Secondary Air Injection System Control B Circuit Low
- P2254O2 Sensor Negative Current Control Circuit Low (Bank 2 Sensor 1)
- P2255O2 Sensor Negative Current Control Circuit High (Bank 2 Sensor 1)
- P2256O2 Sensor Heater Control Circuit Low Bank 1 Sensor 2
- P2258Secondary Air Injection System Control A Circuit High
- P225ANOx Sensor Calibration Memory (Bank 1 Sensor 1)
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.