OBD-II code · Powertrain (generic, extended)
P2259 Secondary Air Injection System Control B Circuit Low
The drive line for secondary air injection (AIR) control circuit B is stuck low. Secondary air is pumped into the exhaust manifold during cold start to speed up catalyst light-off.
Is it safe to drive with P2259?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyShort to ground
- Less likelyConnector pins corroded - high contact resistance
- Less likelyHarness chafing through insulation
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.5–2.5 h
- Emissions test
- Likely to fail
- Parts involved
- Secondary Air Injection Pump, Secondary Air Injection Valve
Related codes
- P2257Secondary Air Injection System Control A Circuit Low
- 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)
- P225BNOx Sensor Calibration Memory (Bank 1 Sensor 2)
- P225CNOx Sensor Performance - Signal Biased/Stuck High (Bank 1 Sensor 1)
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.