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.
General code reference. Confirm the definition and diagnostic procedure for your vehicle's year, model and engine. A stored code alone does not identify a failed part.
Affected components
- Secondary air injection pump
- Secondary air injection valve
Possible causes to check
These are possible checks, not a ranked diagnosis. Follow the vehicle manufacturer's test procedure before replacing parts.
- Short to ground
- Connector pins corroded - high contact resistance
- Harness chafing through insulation
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
Related codes
Sources
Check each reference's vehicle and model-year scope. General background links do not establish which fault is most likely on your vehicle.
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.