Generic Scan Tool

Secondary Air Injection System

• Always replace seals and gaskets.

• Vacuum lines and hose connections must not have leaks.

• Vacuum hoses must not be clogged or kinked.

• For the electric components to work properly, a voltage of at least 11.5 V is required.

• Engine Control Module (ECM) is equipped with On Board Diagnostic (OBD).

• Components marked with * are tested via On Board Diagnostic (OBD) , Diagnostic mode 3: Check DTC memory.

• It is possible that the control module will recognize a malfunction and store a DTC during some tests. Therefore the following work steps must be performed in the mentioned sequence after ending all tests and repairs.

--> [ Secondary Air Injection System, Checking for Leaks ] Secondary Air Injection System, Checking For Leaks

--> [ Secondary Air Injection Valve, Checking ] Secondary Air Injection Valve, Checking

--> [ Secondary Air Injection Pump Motor, Checking ] Secondary Air Injection Pump Motor, Checking

--> [ Combination Valve, Checking ] Combination Valve, Checking

Observe Safety Precautions: --> [ Safety Precautions ] Safety Precautions

Observe Clean Working Conditions: --> [ Clean Working Conditions ] Clean Working Conditions

Air is blown behind the exhaust valves by the Secondary Air Injection (AIR) system during a cold start. Thereby, the exhaust is enriched with oxygen, initiating a secondary combustion and therefore shortening the warm-up phase of the catalytic converters. Activation is triggered by the Motronic Engine Control Module (ECM) (J220) via the Secondary Air Injection (AIR) Pump Relay (J299) to the Secondary Air Injection (AIR) Solenoid Valve (N112) (change-over valve) and the combination valve.