Discovery Series II
- When the engine is started, the ECM checks the engine coolant temperature. If Engine Coolant Temperature (ECT) indicates that coolant temperature is less than 131°F (55°C), ECM will activate the Secondary Air Injection (SAI) system. Ensure ECT sensor is operating properly.
- ECT sensor ground is at ECM 52-pin connector C0636 terminal No. 21 (Red/Black wire). ECT sensor input analog 0-5 volt signal is at ECM 52-pin connector C0636 terminal No. 22 (Green wire). See Figure and Figure
. See WIRING DIAGRAMS
article. See Fig 1.
- Battery voltage is supplied to the inertia switch via fuse No. 13 (10-amp) located in the engine compartment fuse/relay box. When inertia switch is closed, battery voltage is supplied to main relay coil. Main relay operation is controlled through ECM main relay coil ground at ECM 24-pin connector C0635 terminal No. 23 (Blue/Red wire). Ensure main relay is operating properly.
- When main relay is energized, battery voltage is supplied to SAI pump relay coil via fusible link No. 2 (50-amp) located in the engine compartment fuse/relay box. SAI pump relay operation is controlled through ground at ECM 52-pin connector C0636 terminal No. 16 (Black/Orange wire).
- When the main relay is energized, battery voltage is supplied the SAI vacuum solenoid valve via fuse No. 2 (15-amp) located in engine compartment fuse/relay box. SAI vacuum solenoid valve operation is controlled through ground at ECM 52-pin connector C0636 terminal No. 4 (Black/Blue wire). SAI vacuum solenoid valve is energized at the same time as the SAI air pump is energized.
Courtesy of LAND ROVER NORTH AMERICA, INC.