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Starting System: Overview Ford Explorer IV

Starter 12 illustrations ~1735 words

Normal Operations

The starting system sequence of operation is as follows

  1. The ignition switch is turned to the START position.
  2. The starter relay is activated.
  3. Voltage is then provided to the starter solenoid.
  4. The starter solenoid engages the drive pinion to the ring gear.
  5. The starter solenoid switches the battery current to the starter motor.
  6. The system remains engaged until the ignition switch is released.

Possible Causes

  1. Battery
  2. Starter motor
  3. Solenoid
  4. Fuse 11 (30 A)
  5. Ignition switch
  6. Transmission range (TR) sensor (4.0L SOHC only)
  7. A short to ground in the positive battery cable
  8. An open in the positive battery cable
  9. An open circuit at the S-terminal
  10. An open circuit at the B-terminal
  11. An open in the battery ground cable
  12. An open circuit in the starter relay input signal circuit CDC35 (BU/WH)
  13. An open circuit in the battery supply to starter relay input signal circuit SBB11 (BU/RD)
  14. An open circuit in the starter relay to the S-connector circuit CDC25 (BN/GN)
  15. An open circuit in the starter relay to powertrain control module (PCM) circuit CDC12 (YE)
  16. A short to ground in circuit CDC25 (BN/GN) or circuit CDC35 (BU/WH)

Scheme 1

Scheme 1: PINPOINT TEST A: THE ENGINE DOES NOT CRANK/THE RELAY DOES/DOES NOT CLICK
Scheme 1: PINPOINT TEST A: THE ENGINE DOES NOT CRANK/THE RELAY DOES/DOES NOT CLICK

Scheme 2

Scheme 2
Scheme 2

Scheme 3

Scheme 3
Scheme 3

Scheme 4

Scheme 4
Scheme 4

Scheme 5

Scheme 5
Scheme 5

Scheme 6

Scheme 6
Scheme 6

Scheme 7

Scheme 7
Scheme 7

Scheme 8

Scheme 8
Scheme 8

Scheme 9

Scheme 9
Scheme 9

Scheme 10

Scheme 10
Scheme 10

Scheme 11

Scheme 11
Scheme 11
  1. A1 CHECK THE BATTERY Check the battery condition and charge. REFER to «CHARGING SYSTEM - GENERAL INFORMATION»(ref-270936) . Is the battery OK? YES : Go to A2 . NO : CHARGE or INSTALL a new battery as required. TEST the system for normal operation.
  2. A2 CHECK FOR PATS DTCs NOTE: The PATS DTCs are the only DTCs of concern in this step. Only repair retrieved non-PATS DTCs if a customer concern is reported. Check for PATS DTCs. Were any PATS DTCs retrieved? YES : Go to «ANTI-THEFT - PASSIVE ANTI-THEFT SYSTEM (PATS)»(ref-270956) to diagnose the PATS DTCs. NO : Go to A3 .
  3. A3 CHECK THE BATTERY GROUND CABLE Measure the voltage between the positive battery post and the battery ground cable connection at the cylinder block. Is the voltage reading greater than 10 volts? YES : Go to A4 . NO : INSTALL a new battery ground cable. TEST the system for normal operation.
  4. A4 CHECK THE STARTER MOTOR GROUND Measure the voltage between the positive battery post and the starter motor case. Is the voltage reading greater than 10 volts? YES : Go to A5 . NO : CLEAN the starter motor mounting flange and make sure the starter motor is correctly mounted. TEST the system for normal operation.
  5. A5 CHECK THE POWER SUPPLY TO THE STARTER MOTOR Key in OFF position. Measure the voltage at the starter motor B-terminal. Is the voltage reading greater than 10 volts? YES : Go to A6 . NO : CLEAN, TIGHTEN or INSTALL a new positive battery cable. TEST the system for normal operation.
  6. A6 CHECK THE STARTER MOTOR Connect one end of a jumper wire to the B-terminal of the starter motor and momentarily connect the other end to the starter solenoid S-terminal. Does the starter motor engage and the engine crank? YES : Go to A7 . NO : INSTALL a new starter motor. REFER to «Starter Motor - 4.0L SOHC»(ref-270900-S06268113852007110700000) or «Starter Motor - 4.6L (3V)»(ref-270900-S17554403292007110700000) . TEST the system for normal operation.
  7. A7 CHECK THE START INPUT TO THE STARTER MOTOR Disconnect: Starter S-Connector Hold the ignition switch in the START position. Measure the voltage at the starter motor solenoid S-connector. Is the voltage reading greater than 10 volts? YES : CLEAN the starter solenoid S-terminal and connector. CHECK the wiring and the starter motor for a loose or intermittent connection. TEST the system for normal operation. NO : Go to A8 .
  8. A8 CHECK THE START INPUT TO THE STARTER RELAY Disconnect: Starter Relay Key in START position. Measure the voltage at starter relay pin 86, circuit CDC35 (BU/WH). Is the voltage reading greater than 10 volts? YES : Go to A9 . NO : REPAIR circuit CDC35 (BU/WH) for an open. TEST the system for normal operation.
  9. A9 CHECK THE BATTERY SUPPLY TO THE STARTER RELAY Key in OFF position. Measure the voltage at starter relay pin 30, circuit SBB11 (BU/RD). Is the voltage reading greater than 10 volts? YES : Go to A10 . NO : Vehicles equipped with a 4.0L engine, go to A14 . Vehicles equipped with a 4.6L engine, go to A21 .
  10. A10 CHECK CIRCUIT CDC25 (BN/GN) FOR A SHORT TO GROUND Disconnect: Starter S-Connector Measure the resistance between starter relay pin 87, circuit CDC25 (BN/GN) and ground. Is the resistance reading less than 10,000 ohms? YES : REPAIR circuit CDC25 (BN/GN) for a short to ground. TEST the system for normal operation. NO : Go to A11 .
  11. A11 CHECK CIRCUIT CDC25 (BN/GN) FOR AN OPEN Measure the resistance of circuit CDC25 (BN/GN) between starter relay pin 87 and the starter S-connector. Is the resistance reading less than 5 ohms? YES : Go to A12 . NO : REPAIR circuit CDC25 (BN/GN) for an open. TEST the system for normal operation.
  12. A12 CHECK CIRCUIT CDC12 (YE) FOR AN OPEN Disconnect: Powertrain Control Module (PCM) C175B Measure the resistance between starter relay pin 85, circuit CDC12 (YE) and PCM C175B pin 2, circuit CDC12 (YE). Is the resistance less than 5 ohms? YES : Go to A13 . NO : REPAIR circuit CDC12 (YE) for an open. TEST the system for normal operation.
  13. A13 CHECK THE STARTER RELAY Carry out the starter mini ISO relay component test. Refer to COMPONENT TESTING. Is the starter relay good? YES : DIAGNOSE the powertrain control module. REFER to the «Introduction - Gasoline Engines»(ref-268480) . NO : INSTALL a new starter relay. TEST the system for normal operation.
  14. A14 CHECK THE START INPUT TO THE TRANSMISSION RANGE (TR) SENSOR Disconnect: TR Sensor C167 Key in START position. Measure the voltage at the TR sensor C167 pin 10, circuit CDC35 (BU/WH). Is the voltage reading greater than 10 volts? YES : Go to A15 . NO : Go to A18 .
  15. A15 CHECK CIRCUIT CDC35 (BU/WH) FOR AN OPEN Measure the resistance between starter relay pin 86, circuit CDC35 (BU/WH) and TR sensor C167 pin 12, circuit CDC35 (BU/WH). Is the resistance reading less than 5 ohms? YES : Go to A16 . NO : REPAIR circuit CDC35 (BU/WH) for an open. TEST the system for normal operation.
  16. A16 CHECK CIRCUIT CDC35 (BU/WH) FOR A SHORT TO GROUND Measure the resistance between TR sensor C167 pin 12, circuit CDC35 (BU/WH) and ground. Is the resistance reading less than 10,000 ohms? YES : REPAIR circuit CDC35 (BU/WH) for a short to ground. TEST the system for normal operation. NO : Go to A17 .
  17. A17 CHECK TR SENSOR ADJUSTMENT Carry out the TR sensor adjustment. Refer to «AUTOMATIC TRANSAXLE/TRANSMISSION - 5R55S»(ref-270891) . Is the TR sensor adjusted correctly? YES : INSTALL a new TR sensor. TEST the system for normal operation. NO : ADJUST the TR sensor as necessary. TEST the system for normal operation.
  18. A18 CHECK FOR BATTERY POWER AT THE IGNITION SWITCH Disconnect: Ignition Switch C250 Measure the voltage at ignition switch C250 pin 4, circuit SBP08 (VT/RD). Is the voltage reading greater than 10 volts? YES : Go to A19 . NO : REPAIR circuit SBP08 (VT/RD). TEST the system for normal operation.
  19. A19 CHECK CIRCUIT CDC35 (BU/WH) FOR AN OPEN Check the resistance between ignition switch C250 pin 7, circuit CDC35 (BU/WH) and TR sensor C167 pin 10, circuit CDC35 (BU/WH). Is the resistance reading less than 5 ohms? YES : Go to A20 . NO : REPAIR circuit CDC35 (BU/WH) for an open. TEST the system for normal operation.
  20. A20 CHECK CIRCUIT CDC35 (BU/WH) FOR A SHORT TO GROUND Measure the resistance between ignition switch C250 pin 7, circuit CDC35 (BU/WH) and ground. Is the resistance reading greater than 10,000 ohms? YES : INSTALL a new ignition switch. TEST the system for normal operation NO : REPAIR circuit CDC35 (BU/WH) for a short to ground. TEST the system for normal operation.
  21. A21 CHECK FOR BATTERY POWER AT THE IGNITION SWITCH Disconnect: Ignition Switch C250 Measure the voltage at ignition switch C250 pin 4, circuit SBP08 (VT/RD). Is the voltage reading greater than 10 volts? YES : Go to A22 . NO : REPAIR circuit SBP08 (VT/RD). TEST the system for normal operation.
  22. A22 CHECK CIRCUIT CDC35 (BU/WH) FOR AN OPEN Measure the resistance between ignition switch C250 pin 7, circuit CDC35 (BU/WH) and starter relay pin 86, circuit CDC35 (BU/WH) Is the resistance less than 5 ohms? YES : Go to A23 . NO : REPAIR circuit CDC35 (BU/WH) for an open. TEST the system for normal operation.
  23. A23 CHECK CIRCUIT CDC35 (BU/WH) FOR A SHORT TO GROUND. Measure the resistance between ignition switch C250 pin 7, circuit CDC35 and ground. Is the resistance greater than 10,000 ohms? YES : INSTALL a new ignition switch. TEST the system for normal operation. NO : REPAIR circuit CDC35 (BU/WH) for a short to ground. TEST the system for normal operation.

Scheme 12

Scheme 12: PINPOINT TEST B: UNUSUAL STARTER NOISE
Scheme 12: PINPOINT TEST B: UNUSUAL STARTER NOISE
  1. B1 CHECK THE STARTER MOUNTING Inspect the starter mounting bolts and brackets for looseness, and the starter housing to confirm a flush, tight fit to the rear cover plate. Is the starter motor mounted correctly? YES : Go to B2 . NO : INSTALL the starter motor correctly. REFER to «Starter Motor - 4.0L SOHC»(ref-270900-S06268113852007110700000) or «Starter Motor - 4.6L (3V)»(ref-270900-S17554403292007110700000) . TEST the system for normal operation.
  2. B2 CHECK FOR ENGINE NOISE Key in OFF position. Connect a remote starter switch between the starter solenoid B- and S-terminals. Engage the starter motor and verify that the noise is due to the starter operation. Is the noise due to the starter motor engagement? YES : Go to B3 . NO : REFER to «ENGINE SYSTEM - GENERAL INFORMATION»(ref-270909) to continue the diagnosis.
  3. B3 CHECK FOR UNUSUAL WEAR Remove the starter motor. Refer to «Starter Motor - 4.0L SOHC»(ref-270900-S06268113852007110700000) or «Starter Motor - 4.6L (3V)»(ref-270900-S17554403292007110700000) . Inspect the ring gear for damaged or worn teeth. Is the noise due to ring gear tooth damage? YES : INSTALL a new ring gear. EXAMINE the starter pinion teeth. If damaged, INSTALL a new starter motor. TEST the system for normal operation. NO : INSTALL a new starter motor. REFER to «Starter Motor - 4.0L SOHC»(ref-270900-S06268113852007110700000) or «Starter Motor - 4.6L (3V)»(ref-270900-S17554403292007110700000) . TEST the system for normal operation.

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