Normal Operation

Under normal operation, the Battery Junction Box (BJB) supplies constant power to the starter motor relay on circuit SBB11 (BU/RD) through fuse 11 (30A). On vehicles with automatic transaxles, when the key is placed in the START position with the vehicle in PARK or NEUTRAL, the Transmission Range (TR) sensor sends a signal to the PCM and provides ground to the starter motor relay. On vehicles with manual transaxles, when the key is placed in the START position with the clutch pedal depressed, the clutch cutoff switch sends a signal to the PCM and provides ground to the starter motor relay. This allows power to be supplied from the starter motor relay contacts which then flows through circuit CDC25 (BN/GN) 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 closes the solenoid contacts, allowing power directly from the battery through circuit SDC02 (RD) to the starter motor to start the engine.

This pinpoint test is intended to diagnose the following: 

• Battery
• Anti-theft system
• Starter relay
• Ignition switch
• Circuitry
• TR  sensor (automatic transaxle)
• Clutch cutoff switch (manual transaxle)
• PCM
• Start diode