Secondary Air Injection System Pump Stuck On (Bank 1)
The secondary-air pump continues to run after the cold-start window, when the ECU has commanded it off. Usually a stuck-closed relay welding the pump permanently to battery voltage.
Affected components
- Secondary air pump
- Secondary air pump relay
Common causes
- High likelihood: Pump relay stuck closed
- Medium likelihood: Drive line shorted to supply
- Low likelihood: Carbon or debris buildup preventing free movement
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
- A drive cycle may be required after repair
Related codes
Sources
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.