Starting System: Overview Ford Explorer V

Overview

The starter system controls the cranking of the engine. The starter motor is enabled by the starter relay when the relay is activated by the PCM. The ignition switch provides voltage to the BCM and PCM to initiate cranking of the engine.

The starter system controls the starting of the vehicle. The starter is enabled by the starter relay when the relay is activated by the PCM. The PCM receives inputs from the start/stop switch, BCM and TR sensor before activating the starter relay to crank the engine.

Normal Operation and Fault Conditions

When the ignition switch is turned to the START position, the BCM and PCM receive a request to crank the engine. When the PCM receives the correct inputs from the BCM and notification from the TR sensor that the gear selector is in PARK or NEUTRAL, the PCM then supplies voltage and ground to the starter relay coil. The energized coil causes the starter relay contacts to close. This allows voltage to be supplied from the BJB to the starter solenoid coil. The starter solenoid coil is grounded at the starter motor. Energizing the starter solenoid closes the solenoid contacts allowing voltage directly from the battery to the starter motor, engaging the starter drive into the ring gear causing the engine to crank. The PCM disengages the starter motor once an engine RPM threshold is reached, a set crank time is exceeded or the ignition switch has been turned to the OFF position.

Visual Inspection and Diagnostic Pre-checks

1. Inspect the battery.
2. Inspect the battery cables.
3. Inspect BJB fuse 19 (30A).
4. Inspect BCM fuse 28 (15A).
5. Inspect the starter motor.
6. Inspect the starter motor bolts.
7. Inspect the IKT.
8. Inspect the starter relay.
9. Inspect high current battery junction box connections.

When the start/stop switch is pressed in combination with the brake pedal, the RFA module, BCM and PCM receive signals to crank and start the engine. The PCM and RFA module received notification from the TR sensor that the gear selector is in PARK or NEUTRAL. The PCM then supplies voltage and ground to the starter relay coil. The energized coil causes the starter relay contacts to close. This allows voltage to be supplied from the BJB to the starter solenoid coil. The starter solenoid coil is grounded at the starter motor. Energizing the starter solenoid closes the solenoid contacts allowing voltage directly from the battery to the starter motor, engaging the starter drive into the ring gear causing the engine to crank. The PCM disengages the starter motor once an engine RPM threshold is reached, a set crank time is exceeded or the start/stop switch is pressed indicating an engine shutdown.

Visual Inspection and Diagnostic Pre-checks

1. Inspect the battery.
2. Inspect the battery cables.
3. Inspect BJB fuse 19 (30A).
4. Inspect BCM fuse 28 (15A).
5. Inspect the starter motor.
6. Inspect high current battery juction box connections.
7. Inspect the starter motor.
8. Inspect the starter relay.
9. Inspect the start/stop switch.

Correct starter operation relies on correct mounting of the starter to the engine, alignment of the starter ring gear to the flywheel and correct functioning of the starter assembly (internal gears, bearings).

Visual Inspection and Diagnostic Pre-checks

1. Inspect the starter motor.
2. Inspect the starter motor mounting.

The wake up control circuit is used to wake up the PCM prior to engine cranking. The PCM needs to wake up prior to a crank request so that it has time to go through its own initialization. The wake up control circuit also powers the PATS transceiver (if equipped). The wake up control circuit is controlled by the BCM and receives voltage from the BJB. The wake up control circuit is FET protected. REFER to FIELD EFFECT TRANSISTOR (FET) PROTECTION .

The BCM activates the wake-up control circuit when

1. the driver door is opened.
2. a remote start request is received (if equipped with factory remote start).
3. the brake pedal is pressed.
4. a key is inserted into the ignition (without IA)
5. the ignition is in the RUN or START position.
6. the start/stop switch is pressed (with IA)

DTC FAULT TRIGGER CONDITIONS

Visual Inspection and Diagnostic Pre-checks

1. Inspect BCM fuse 18 (10A).

Scheme 1

Scheme 2

Scheme 3

Scheme 4

Scheme 5

1. RETRIEVE BCM DTCs Ignition ON. Using a scan tool, perform the BCM self-test. Is DTC C113A:15 retrieved? Yes: GO to 2 . No: For DTC C113A:11, GO to 7 . For all other BCM DTCs , REFER to «DTC CHART: BODY CONTROL MODULE (BCM)»(ref-517607-S42107110602012121200000) .
2. CHECK THE WAKE UP CONTROL CIRCUIT FOR A SHORT TO VOLTAGE Ignition OFF. Disconnect: PATS Transceiver (for vehicles without IA only). Disconnect: BCM C2280F. Disconnect: PCM C1381B (2.0L) or PCM C175B (3.5L). Ignition ON. For 2.0L, measure: PCM Ground C1381B Ground Pin Circuit Measurement / Action Pin Circuit 14 CE436 (VT/OG) - Ground For 3.5L, measure: PCM Ground C175B Ground Pin Circuit Measurement / Action Pin Circuit 35 CE436 (VT/OG) - Ground Is any voltage present? Yes: REPAIR the circuit. No: For vehicles with IA, GO to 3 . For vehicles without IA, GO to 5 .
3. CHECK THE WAKE UP CONTROL CIRCUIT FOR AN OPEN Ignition OFF. For 2.0L, measure: PCM BCM C1381B C2280F Pin Circuit Measurement / Action Pin Circuit 14 CE436 (VT/OG) 5 CE436 (VT/OG) For 3.5L, measure: PCM BCM C175B C2280F Pin Circuit Measurement / Action Pin Circuit 35 CE436 (VT/OG) 5 CE436 (VT/OG) Is the resistance less than 3 ohms? Yes: GO to 4 . No: REPAIR the circuit.
4. CHECK THE BCM AND PCM FOR CORRECT OPERATION Connect: BCM C2280F. Ignition ON. For 2.0L, measure: PCM Ground C1381B Ground Pin Circuit Measurement / Action Pin Circuit 14 CE436 (VT/OG) - Ground For 3.5L, measure: PCM Ground C175B Ground Pin Circuit Measurement / Action Pin Circuit 35 CE436 (VT/OG) - Ground Is the voltage greater than 11 volts? Yes: GO to 11 . No: VERIFY BCM fuse 18 (10A) is OK. If OK, GO to 10 . If not OK, REFER to the appropriate wiring diagram to identify the possible causes of the circuit short. REFER to «OEM FUSE AND RELAY INFORMATION»(ref-485835) and «OEM WIRING DIAGRAMS»(ref-514995) .
5. CHECK THE WAKE UP CONTROL CIRCUIT FOR AN OPEN Ignition OFF. Measure: PATS BCM C252 C2280F Pin Circuit Measurement / Action Pin Circuit 1 CE436 (VT/OG) 5 CE436 (VT/OG) Is the resistances less than 3 ohms? Yes: GO to 6 . No: REPAIR the circuit.
6. CHECK THE BCM FOR CORRECT OPERATION Connect: BCM C2280F. Ignition ON. Measure: PATS Ground C252 Ground Pin Circuit Measurement / Action Pin Circuit 1 CE436 (VT/OG) - Ground Is the voltage greater than 11 volts? Yes: INSTALL a new PATS transceiver (vehicles without IA only). REFER to «PASSIVE ANTI-THEFT SYSTEM (PATS) TRANSCEIVER»(ref-517598-S07156968542012121200000) . No: VERIFY BCM fuse 18 (10A) is OK. If OK, GO to 10 . If not OK, REFER to the appropriate wiring diagram to identify the possible causes of the circuit short. REFER to «OEM FUSE AND RELAY INFORMATION»(ref-485835) and «OEM WIRING DIAGRAMS»(ref-514995) .
7. CHECK THE WAKE UP CONTROL CIRCUIT DTC FOR A FAULT STATUS CHANGE (SHORT TO GROUND INDICATED) Using a scan tool, clear the BCM CMDTCs . Ignition OFF. Disconnect: PATS Transceiver (for vehicles without IA only). Disconnect: PCM C1381B (2.0L) or PCM C175B (3.5L). Ignition ON. Using a scan tool, perform the PCM self-test. Was DTC C113A:11 retrieved on-demand during self-test? Yes: GO to 8 . No: GO to 9 .
8. CHECK THE WAKE UP CONTROL CIRCUIT FOR A SHORT TO GROUND Ignition OFF. Disconnect: BCM C2280F. For 2.0L, measure: PCM Ground C1381B Ground Pin Circuit Measurement / Action Pin Circuit 14 CE436 (VT/OG) - Ground For 3.5L, measure: PCM Ground C175B Ground Pin Circuit Measurement / Action Pin Circuit 35 CE436 (VT/OG) - Ground Is the resistance to ground greater than 10, 000 ohms? Yes: GO to 10 . No: REPAIR the circuit.
9. CHECK THE PCM FOR CORRECT OPERATION Using a scan tool, clear the BCM CMDTCs . Ignition OFF. Connect: PCM C1381B (2.0L) or PCM C175B (3.5L). Ignition ON. Using a scan tool, perform the BCM self-test. Was DTC C113A:11 retrieved on-demand during self-test? Yes: GO to 11 . No: For vehicles without IA, INSTALL a new PATS transceiver (vehicles without IA only). REFER to «PASSIVE ANTI-THEFT SYSTEM (PATS) TRANSCEIVER»(ref-517598-S07156968542012121200000) . For vehicles with IA, the system is operating correctly at this time. The concern may have been caused by loose or corroded connector. ADDRESS the root cause of any connector or pin issues.
10. CHECK FOR CORRECT BCM OPERATION Ignition OFF. Disconnect and inspect all BCM connectors. Repair: corrosion (install new connector or terminals - clean module pins) damaged or bent pins - install new terminals/pins pushed-out pins - install new pins as necessary Reconnect the BCM connectors. Make sure they seat and latch correctly. Operate the system and determine if the concern is still present. Is the concern still present? Yes: CHECK OASIS for any applicable TSBs . If a TSB exists for this concern, DISCONTINUE this test and FOLLOW the TSB instructions. If no TSBs address this concern, INSTALL a new BCM. REFER to «BODY CONTROL MODULE (BCM) - WITH INTELLIGENT ACCESS (IA)»(ref-517607-S22029955872012121200000) or REFER to «BODY CONTROL MODULE (BCM) - WITHOUT INTELLIGENT ACCESS (IA)»(ref-517607-S10277508012012121200000) . No: The system is operating correctly at this time. The concern may have been caused by module connections. ADDRESS the root cause of any connector or pin issues.
11. CHECK FOR CORRECT PCM OPERATION Ignition OFF. Disconnect and inspect all PCM connectors. Repair: corrosion (install new connector or terminals - clean module pins) damaged or bent pins - install new terminals/pins pushed-out pins - install new pins as necessary Reconnect the PCM connectors. Make sure they seat and latch correctly. Operate the system and determine if the concern is still present. Is the concern still present? Yes: CHECK OASIS for any applicable TSBs . If a TSB exists for this concern, DISCONTINUE this test and FOLLOW the TSB instructions. If no TSB address this concern, INSTALL a new PCM. REFER to «POWERTRAIN CONTROL MODULE (PCM) - 2.0L GTDI»(ref-517566-S00665914912012121200000) or REFER to «POWERTRAIN CONTROL MODULE (PCM) - 3.5L TI-VCT»(ref-517566-S09666002682012121200000) . No: The system is operating correctly at this time. The concern may have been caused by module connections. ADDRESS the root cause of any connector or pin issues.