Charging and starting operation (page 2 of 2)

The immobilisation system consists of the following components: Transponder in the ignition key Passive immobilisation coil (receiver) Engine immobilisation control unit Engine Immobilisation warning light (in instrument pack) When the proper ignition key is inserted in the ignition and turned to position II, the engine immobilisation control unit sends a signal to the transponder via the passive immobilisation coil. The transponder then sends a coded signal back to the engine immobilisation control unit via the passive immobilisation coil. The engine immobilisation control unit then sends a signal to the ECM (EM control unit) to enable the engine management system and provides earth to the starter relay (via the automatic inhibitor switch for vehicles fitted with an automatic gearbox) to enable the starting system. The engine immobilisation warning light will be lit for approximately 2 seconds and then will turn off.

Battery voltage is applied constantly to the ignition switch and the engine immobilisation control unit by the W and the Y/U wires respectively. When the proper ignition key is turned to position III, voltage is applied to the starter relay’s coil via the B/W wire. On vehicles fitted with manual gearboxes, the engine immobilisation control unit provides earth directly to the other side of the starter relay’s coil and the relay energises. On vehicles fitted with automatic gearboxes, the engine immobilisation control unit provides earth to the automatic inhibitor switch. If the vehicle is in PARK or NEUTRAL, earth is then applied to the other side of the starter relay’s coil and the relay energises. Voltage is then applied on the B/W wire to the starter solenoid. The starter solenoid energises and battery voltage is applied directly to the starter motor from the battery.

CAUTION: It is possible, if the RED (learning) key has been used, for the engine immobiliser signal to energise the starter relay but NOT be recognised by the ECM (EM control unit). If this happens, TestBook will be required to resynchronise the system. Always follow the procedure in the Workshop Manual when using the RED key.