Secondary Air Injection System Components

ENGINE MANAGEMENT SYSTEM – V8

18-2-58 DESCRIPTION AND OPERATION

Secondary Air Injection System Components
The secondary air injection (SAI) system components are described below:

Secondary Air Injection (SAI) Pump

The SAI pump is attached to a bracket at the front LH side of the engine compartment and is fixed to the bracket by 
three studs and nuts. The pump is electrically powered from a 12V battery supply via a dedicated relay and supplies 
approximately 35kg/hr of air when the vehicle is at idle in Neutral/Park on a start from 20

°

C (68

°

F).

Air is drawn into the pump from the "clean" side of the air cleaner. The air is delivered to the cylinder head on each 
side of the engine through a metal pipe.

The foam filter in the air intake of the SAI pump provides noise reduction and protects the pump from damage due to 
particulate contamination.

If the secondary air injection pump malfunctions, fault codes may be stored in the ECM diagnostic memory, which can 
be retrieved using Testbook/T4.

Secondary Air Injection (SAI) Pump Relay
The secondary air injection pump relay, coloured pink for identification, is located in the E-Box. The engine control 
module (ECM) is used to control the operation of the SAI pump via the SAI pump relay. Power to the coil of the relay 
is supplied from the vehicle battery via the main relay and the ground connection to the coil is via the ECM.

Secondary Air Injection Non Return Valve
The secondary air injection non return valve is located on the steel air delivery tube at the front of the engine. The 
valve is controlled by the ECM via the vacuum vent solenoid.

Vacuum Vent Valve