Mercedes - Secondary Air Injection System Issues


Mercedes - Secondary Air Injection System IssuesThis is a critical system in your Mercedes that helps decrease tailpipe emissions while the car is warming up. Within 10 minutes, and often in a much shorter time frame, the system will shut down, as it is no longer needed until the next time the car is started. The system works by using an air pump to inject fresh air into the cylinders to lean out the rich fuel mixture that occurs during engine startup. This increases combustion temperatures, which in turn decreases catalyst warm up time, thus ensuring cleaner emissions during a cold start.

Possible Symptoms of a Failed Secondary Air Injection System

On the surface it can be difficult to tell if your Mercedes is suffering from issues with its secondary air injection system. While you may notice engine hesitation upon startup, it is more likely the Service Engine Soon light will come on. It is always important to head to a qualified Mercedes repair center when the engine light comes on so that proper diagnostics can be completed. In the case of a malfunction with the secondary air injection system, the car's computer will trigger the light if the system does not detect the presence of certain levels of oxygen in the exhaust when air is being introduced by the secondary air injection system.

Possible Causes

There are several possible causes of a faulty secondary air injection system, which may include:

  • Vacuum hose damage
  • Faulty air pump
  • Poor electrical connection of air bypass solenoid
  • Air bypass solenoid harness is shorted or open
  • Air bypass solenoid is leaking or blocked
  • Air diverter valve is stuck open or closed
  • Air diverter valve is leaking or blocked

A clogged diverter valve is one of the more common problems found when the system is malfunctioning. If particles in the air get in the air supply system, it may cause clogs and an obstruction of airflow inside the diverter valve. This can eventually cause interior components of the unit to heat up, resulting in a broken valve.

How & why cleaning products are important to prevent these problems

If you believe that your Mercedes is having issues with its secondary air injection system, including a clogged diverter valve, be sure to reach out to a professional European auto repair shop. At G2 Automotive we offer expert Mercedes secondary air injection system repair in Cumming, GA, and we can assist with preventative maintenance, such as the use of intake cleaning products. As soon as you notice a problem with the way your car runs or drives, or if the check engine light has come on, don't hesitate to contact G2 to schedule an appointment for professional Mercedes repair in Cumming. Give us a call at (678) 771-6434 and we will be happy to accommodate you.


G2 Automotive Blog

Written and Published By MORBiZ