What it means
The switching valve on bank 1 will not open when commanded, so no secondary air reaches the exhaust during cold start. Catalyst light-off is delayed and emissions during the cold-start window rise.
At a glance
- Usually lights the check-engine light
- Affects emissions; the car can fail an emissions test
How it works
The secondary air injection switching valve for bank 1 should open during cold starts so air reaches that bank's exhaust and helps the catalyst warm up. This code sets when the control module detects that the valve remains closed or airflow does not pass as expected, increasing cold-start emissions.
Common causes
Most likely first.
- Switching valve stuck closed by carbon
- Vacuum control line leak
- Carbon or debris buildup preventing free movement
Symptoms
- Check engine light on
- Rough idle or hesitation during cold start
- Reduced engine performance
- Failed emissions inspection
How to diagnose it
- Use a scan tool to review freeze-frame data and command the bank 1 secondary air system during a cold-start test, observing valve response and oxygen-sensor data.
- Inspect the bank 1 air pipes and switching valve for carbon, debris, corrosion, or a blocked passage that could prevent airflow.
- Check the valve's electrical connector and wiring, and inspect any vacuum-control line fitted to this system for leaks or disconnection.
- Test the bank 1 valve actuator and confirm that the valve opens under the vehicle's service procedure.
- If the valve opens but airflow is still absent, check the secondary air pump and bank 1 plumbing for blockage or failure.
Common fixes
- Reconnect or repair a leaking vacuum-control line for the bank 1 valve, if fitted.
- Repair loose or damaged bank 1 valve wiring or connector terminals.
- Remove permitted carbon or debris, or replace the bank 1 switching valve if it will not open.
- Repair or replace a failed secondary air pump or blocked bank 1 air pipe after confirming the cause.
Can I keep driving?
Normal driving is usually possible if there are no other faults or severe symptoms, but arrange repair because cold-start emissions can rise and the vehicle may fail an emissions inspection. Avoid repeated cold-start testing that leaves the fault unresolved.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.