Secondary air injection system components (Emission control - V8) (page 4 of 6)

Electrical connection to the SAI vacuum solenoid valve is via a 2–pin connector. A 12V electrical power supply to the SAI vacuum solenoid valve is provided via the Main relay and Fuse 2 in the engine compartment fusebox. The ground connection is via the ECM which controls the SAI vacuum solenoid valve operation. Note that the harness connector to the SAI solenoid valve is grey, and must not be confused with the harness connector to the EVAP system purge valve which is black.

The ECM switches on the SAI vacuum solenoid valve at the same time as initiating SAI pump operation. When the SAI vacuum solenoid valve is open, a steady vacuum supply is allowed through to open the two vacuum operated SAI control valves. When the ECM breaks the earth path to the SAI vacuum solenoid valve, the valve closes and immediately shuts off the vacuum supply to the two SAI control valves at the same time as the SAI pump operation is terminated.

If the SAI vacuum solenoid valve malfunctions, the following fault codes may be stored in the ECM diagnostic memory, which can be retrieved using 'Testbook':

SAI control valves

1

4

1 Pressurised air from SAI pump 2 Vacuum operated SAI control valve 3 Vacuum hose from SAI vacuum solenoid valve

2

3

6

5

4

4 Pressurised air to exhaust manifold 5 Protective heat sleeving 6 Air delivery pipe to exhaust manifold