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Home >> Ford >> 2009 >> Flex Limited, FWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 703 (Starting System - F-150 & Mark LT) >> Diagnostic Tests >> Starting System >> Pinpoint Tests >> Pinpoint Test C: The Engine Does Not Crank and the Relay Does Not Click (Late Build Vehicles) >> Normal Operation

Normal Operation

WARNING: This page is about a different car, the 2007 Lincoln Mark LT and 2007 Ford Pickup. However, it is still accessible from the selected car via links, so may be relevant.

Under normal operation, when the ignition switch is turned in the START position and released, the powertrain control module (PCM) receives a starter motor request (SMR) signal through circuit 1522 (DG). The digital transmission range (TR) sensor (automatic transmission) will receive a signal from circuit 325 (DB/OG), if the vehicle is in PARK or NEUTRAL, power is supplied to the starter relay through circuit 1093 (TN/RD). The clutch pedal position (CCP) sensor (manual transmission) will send a ground to the PCM through circuit 1903 (WH/BK) with the clutch depressed. A ground is supplied to the starter relay through circuit 1785 (LG/VT) from the PCM causing the starter relay coil to energize and the relay contacts to close. This allows power to be supplied from central junction box (CJB) fuse 101 (30A) to the starter relay contacts, which then flows through circuit 113 (YE/LB) to the starter solenoid. The solenoid is grounded at the starter motor. Energizing the starter solenoid will engage the starter drive into the ring gear and close the solenoid contacts allowing power directly from the battery through circuit 2037 (RD) to the starter motor to start the engine. The PCM will disengage the starter motor based on engine running (rpm threshold), a set crank time has been exceeded or the ignition switch has been turned to the OFF position.

Possible Causes

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