Vehicles Without Key Transponder Module (KTM)
Engine cranking is controlled by ignition switch, Engine Control Module (ECM), Body Processor Module (BPM), park/neutral switch, and not-in-park switch at gear selector. See Fig 1. In ignition ON position (II) and with gear selector in Park, ECM enables fuel and ignition and outputs a security signal to BPM. The BPM receives park signal from not-in-park switch at gear selector and enables cranking if security system has been disarmed. With ignition switch in START position (III), crank signal is received by BPM. The BPM grounds starter relay coil to energize starter. The ECM receives starter relay coil signal and sets engine starting values. The ECM reacts to a signal from the BPM when the starter motor relay is energized. This signal is used to trigger starting, fuel and ignition strategies.