How is secondary air injection system diagnosed?
To start the diagnosis, ensure the engine is cold and take note of the front O2 sensor from the scan tool data stream. You should be able to hear the secondary air pump start after 5 to 10 seconds – it’s a vacuum cleaner-like sound that runs under the hood of the vehicle.
How do you test a secondary air valve?
The secondary air valve can be quickly inspected in an easy way:
- Loosen the connecting hose on the secondary air non-return valve leading to the secondary air pump.
- If there are deposits on this side of the valve (finger test, see Fig.
- Inspect the secondary air pump and replace it if necessary.
What causes a secondary air pump to fail?
Common secondary air injection system problems. While air pump failures do occur, it should be noted that pump failures are almost always caused by corrosion that derives from water or moisture in exhaust gas that finds its way into the pump enclosure.
Can I drive without secondary air injection?
You will be fine driving to work in the morning. You will get or already have a CEL for hose being disconnected. The pump only runs for a minute or so on cold start to help burn exhaust gases and heat up the O2 sensor. The reason for the brown color is most likely due to rust from condensation in the pump.
Faulty ground and voltage supply can also cause the pump to fail. Blocked or leaking lines can also cause the failure or malfunction of the control or combination valve, resulting in the failure of the secondary air system. As for all other troubleshooting and diagnostic work, begin with visual checks, and additionally an acoustic check.
How to check the secondary air injection system?
At the control valve fitting, it should be possible to detect a vacuum (a vacuum pump can also be connected) as soon as the secondary air pump begins to operate. The function of the combination valve can be checked using a vacuum pump. For this, remove the vacuum line at the combination valve and connect the vacuum pump to the valve.
How to check the function of the combination valve?
The function of the combination valve can be checked using a vacuum pump. For this, remove the vacuum line at the combination valve and connect the vacuum pump to the valve. Now loosen the hose fitting from the secondary air pump to the combination valve at the pump. Blow air into the line with a slight pressure (do not use compressed air).
What causes the secondary air ignition to fail?
The entire secondary air ignition system can fail due to a malfunctioning combination valve, and the most common reason for this problem to occur is a leaked or blocked line in the system. Does Engine Performance Depend on the Exhaust System?