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Pinpoint Test

Pinpoint Test A: The Engine Does Not Crank/ The Relay Does/Does Not Click 

Refer to appropriate SYSTEM WIRING DIAGRAMS article, Starting System for schematic and connector information.

Normal Operation 

Under normal operation, voltage from the battery junction box (BJB) is supplied to the ignition switch through circuit SBB09 (RD). When the ignition switch is placed in the START position, voltage is supplied through circuit CDC35 (BU/WH) to smart junction box (SJB) fuse 21 (5A).

For automatic transmission equipped vehicles, voltage is supplied from SJB fuse 21 (5A) to the digital transmission range (TR) sensor through circuit CBP 21 (BU/GY) and then to the starter relay coil through circuit CET 40 (GN/OG) and CBP 21 (GN/OG). A ground is supplied through circuit CDC12 (YE) and the PCM.

For manual transmission equipped vehicles, voltage is supplied from SJB fuse 21 (5A) to the starter relay coil through circuit CBP 21 (BU/GY). A ground is supplied through circuit CDC12 (YE) and the PCM. The PCM will not supply ground to the starter relay coil unless the clutch is depressed, grounding the clutch pedal position bottom of travel input to the PCM on circuit CDC 36 (GN/BN).

When the starter relay coil is energized, the relay contacts close. This allows power to be supplied from BJB fuse 7 (40A) through circuit SBB07 (WH/RD) to the relay contacts. Power 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. It also closes the solenoid contacts allowing power directly from the battery to energize the starter motor to start the engine.

This pinpoint test is intended to diagnose the following:

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

  1. A1 CHECK THE BATTERY 
    1. YES  : Go to  A2.
    2. NO  : CHARGE or INSTALL a new battery as required. TEST the system for normal operation.
  2. A2 CHECK THE BATTERY GROUND CABLE 
      Fig 1: Checking Battery Ground Cable
      GF0005963Courtesy of FORD MOTOR CO.
    • Measure the voltage between the positive battery post and the battery ground cable connection at the cylinder block or the starter motor mounting stud bolt (for the 4.0L SOHC engine).
    • Is the voltage reading greater than 10 volts? 
    1. YES  : Go to  A3.
    2. NO  : INSTALL a new battery ground cable. TEST the system for normal operation.
  3. A3 CHECK THE STARTER MOTOR GROUND 
      Fig 2: Checking Starter Motor Ground
      GF0005964Courtesy of FORD MOTOR CO.
    • Measure the voltage between the battery positive post and the starter motor case.
    • Is the voltage reading greater than 10 volts? 
    1. YES  : Go to  A4.
    2. NO  : CLEAN the starter motor mounting flange and make sure the starter motor is correctly mounted. TEST the system for normal operation.
  4. A4 CHECK THE POWER SUPPLY TO THE STARTER MOTOR 
      Fig 3: Checking Power Supply To Starter Motor
      GF0000667Courtesy of FORD MOTOR CO.
    • Measure the voltage at the starter motor B terminal.
    • Is the voltage reading greater than 10 volts? 
    1. YES  : Go to  A5.
    2. NO  : INSTALL a new positive battery cable. TEST the system for normal operation.
  5. A5 CHECK THE STARTER MOTOR B TERMINAL 
      Fig 4: Checking Starter Motor
      GF0000668Courtesy of FORD MOTOR CO.
    • 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? 
    1. YES  : Go to  A6.
    2. NO  : INSTALL a new starter motor. TEST the system for normal operation.
  6. A6 CHECK START INPUT TO THE STARTER MOTOR 
    • Disconnect: Starter S Terminal
    • Key in START position.
      • Fig 5: Measuring Voltage
      GF0009535Courtesy of FORD MOTOR CO.
    • Measure the voltage at the starter motor solenoid S terminal.
    • Is the voltage reading greater than 10 volts? 
    1. 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.
    2. NO  : Go to  A7.
  7. A7 CHECK CIRCUIT CDC25 (BN/GN) FOR A SHORT TO GROUND 
    • Disconnect: Starter Relay
      • Fig 6: Measuring Resistance
      GF0047174Courtesy of FORD MOTOR CO.
    • For 2.3L engines, measure the resistance between starter relay connector pin 30, circuit CDC25 (BN/GN) and ground.
      • Fig 7: Measuring Resistance
      GF0047175Courtesy of FORD MOTOR CO.
    • For 3.0L and 4.0L engines, measure the resistance between starter relay connector pin 30, circuit CDC25 (BN/GN) and ground.
    • Is the resistance reading less than 10,000 ohms? 
    1. YES  : REPAIR circuit CDC25 (BN/GN) for a short to ground. CHECK BJB fuse 7 (40 A) for an open. INSTALL a new BJB fuse 7 (40 A) if necessary. TEST the system for normal operation.
    2. NO  : Go to  A8.
  8. A8 CHECK CIRCUIT CDC25 (BN/GN) FOR AN OPEN 
      Fig 8: Measuring Resistance
      GF0047176Courtesy of FORD MOTOR CO.
    • For 2.3L engines, measure the resistance of circuit CDC25 (BN/GN) between starter relay connector pin 30 and the starter solenoid S terminal.
      • Fig 9: Measuring Resistance
      GF0047177Courtesy of FORD MOTOR CO.
    • For 3.0L and 4.0L engines, measure the resistance of circuit CDC25 (BN/GN) between starter relay connector pin 30 and the starter solenoid S terminal.
    • Is the resistance reading 5 ohms or less? 
    1. YES  : Go to  A9.
    2. NO  : REPAIR circuit CDC25 (BN/GN) for an open. TEST the system for normal operation.
  9. A9 CHECK THE BATTERY SUPPLY TO THE STARTER RELAY 
    • Key in OFF position.
      • Fig 10: Measuring Voltage
      GF0047178Courtesy of FORD MOTOR CO.
    • For 2.3L engines, measure the voltage at starter relay connector pin 87, circuit SBB07 (WH/RD).
      • Fig 11: Measuring Voltage
      GF0047179Courtesy of FORD MOTOR CO.
    • For 3.0L and 4.0L engines, measure the voltage at starter relay connector pin 87, circuit SBB07 (WH/RD).
    • Is the voltage reading greater than 10 volts? 
    1. YES  : Go to  A13.
    2. NO  : Go to  A10.
  10. A10 CHECK BJB FUSE 7 (40A) FOR AN OPEN 
    • Key in OFF position.
    • Disconnect: BJB Fuse 7 (40A)
    • Check fuse: BJB Fuse 7 (40A)
    • Is the BJB fuse 7 (40A) open? 
    1. YES  : Go to  A11.
    2. NO  : Go to  A12.
  11. A11 CHECK CIRCUIT SBB07 (WH/RD) FOR A SHORT TO GROUND 
      Fig 12: Measuring Resistance
      GF0047180Courtesy of FORD MOTOR CO.
    • For 2.3L engines, measure the resistance between starter relay connector pin 87, circuit SBB07 (WH/RD) and ground.
      • Fig 13: Measuring Resistance
      GF0047181Courtesy of FORD MOTOR CO.
    • For 3.0L and 4.0L engines, measure the resistance between starter relay connector pin 87, circuit SBB07 (WH/RD) and ground.
    • Is the resistance less than 10,000 ohms? 
    1. YES  : REPAIR circuit SBB07 (WH/RD) for a short to ground. INSTALL a new BJB fuse 7 (40A). TEST the system for normal operation.
    2. NO  : INSTALL a new BJB fuse 7 (40A). TEST the system for normal operation.
  12. A12 CHECK CIRCUIT SBB07 (WH/RD) FOR AN OPEN 
      Fig 14: Measuring Resistance
      GF0047182Courtesy of FORD MOTOR CO.
    • For 2.3L engines, measure the resistance between the output cavity of BJB fuse 7 (40A), circuit SBB07 (WH/RD) and starter relay connector pin 87, circuit SBB07 (WH/RD).
      • Fig 15: Measuring Resistance
      GF0047183Courtesy of FORD MOTOR CO.
    • For 3.0L and 4.0L engines, measure the resistance between the output cavity of BJB fuse 7 (40A), circuit SBB07 (WH/RD) and starter relay connector pin 87, circuit SBB07 (WH/RD).
    • Is the resistance less than 5 ohms? 
    1. YES  : INSTALL a new positive battery cable. TEST the system for normal operation.
    2. NO  : REPAIR circuit SBB07 for an open. TEST the system for normal operation.
  13. A13 CHECK THE START INPUT TO THE STARTER RELAY 
    • Key in START position.
      • Fig 16: Measuring Voltage
      GF0047184Courtesy of FORD MOTOR CO.
    • For 2.3L engines, measure the voltage at the starter relay connector pin 86 circuit CBP21 (BU/GY).
      • Fig 17: Measuring Voltage
      GF0047185Courtesy of FORD MOTOR CO.
    • For 3.0L and 4.0L engines, measure the voltage at the starter relay connector pin 85 circuit CBP21 (BU/GY).
    • Is the voltage reading greater than 10 volts? 
    1. YES  : Go to  A14.
    2. NO  : If the vehicle is equipped with a manual transmission, go to  A22. If the vehicle is equipped with an automatic transmission, go to  A19.
  14. A14 CHECK THE STARTER RELAY GROUND 
    • If the vehicle is equipped with a manual transmission, fully depress the clutch pedal.
    • Key in START position.
      • Fig 18: Measuring Resistance
      GF0047186Courtesy of FORD MOTOR CO.
    • For 2.3L engines, measure the resistance between starter relay connector pin 85 circuit CDC12 (YE) and ground.
      • Fig 19: Measuring Resistance
      GF0047187Courtesy of FORD MOTOR CO.
    • For 3.0L and 4.0L engines, measure the resistance between starter relay connector pin 86 circuit CDC12 (YE) and ground.
    • Is the resistance reading 5 ohms or less? 
    1. YES  : INSTALL a new starter relay. TEST the system for normal operation.
    2. NO  : Go to  A15.
  15. A15 CHECK CIRCUIT CDC12 (YE) FOR AN OPEN 
    • Disconnect: PCM C175B
      • Fig 20: Measuring Resistance
      GF0047188Courtesy of FORD MOTOR CO.
    • For 2.3L engines, measure the resistance between starter relay connector pin 85 circuit CDC12 (YE) and PCM connector C175B-2.
      • Fig 21: Measuring Resistance
      GF0047189Courtesy of FORD MOTOR CO.
    • For 3.0L and 4.0L engines, measure the resistance between starter relay connector pin 86 circuit CDC12 (YE) and PCM connector C175B-2.
    • Is the resistance reading 5 ohms or less? 
    1. YES  : If the vehicle is equipped with a manual transmission, go to  A16. If the vehicle is equipped with an automatic transmission, INSTALL a new PCM. TEST the system for normal operation.
    2. NO  : REPAIR circuit CDC12 (YE) for an open. TEST the system for normal operation.
  16. A16 CHECK CIRCUIT GD174 (BK/WH) FOR AN OPEN 
    • Disconnect: CPP Switch C257
    • Key in OFF position.
      • Fig 22: Measuring Resistance
      GF0009544Courtesy of FORD MOTOR CO.
    • Measure the resistance between CPP switch C257-5, circuit GD174 (BK/WH) and ground.
    • Is the resistance less than 5 ohms? 
    1. YES  : Go to  A17.
    2. NO  : REPAIR circuit GD174 (BK/WH) for an open. TEST the system for normal operation.
  17. A17 CHECK THE CPP SWITCH BOTTOM OF TRAVEL INPUT 
    • Connect: PCM C175B
    • Key in START position.
      • Fig 23: Measuring Voltage
      GF0009545Courtesy of FORD MOTOR CO.
    • Measure the voltage at CPP switch C257-6, circuit CDC36 (GN/BN).
    • Is the voltage greater than 10 volts? 
    1. YES  : INSTALL a new CPP switch. TEST the system for normal operation.
    2. NO  : Go to  A18.
  18. A18 CHECK CIRCUIT CDC36 (GN/BN) FOR AN OPEN 
    • Disconnect: PCM Connector C175B
      • Fig 24: Measuring Resistance
      GF0009546Courtesy of FORD MOTOR CO.
    • Measure the resistance between PCM connector C175B-33, circuit CDC36 (GN/BN) and CPP connector C257-6, circuit CDC36 (GN/BN).
    • Is the resistance less than 5 ohms? 
    1. YES  : INSTALL a new PCM. TEST the system for normal operation.
    2. NO  : REPAIR circuit CDC36 for an open. TEST the system for normal operation.
  19. A19 CHECK CIRCUIT CBP21 (BU/GY) FOR A SHORT TO GROUND 
    • Disconnect: TR Sensor Connector C167
      • Fig 25: Measuring Resistance
      GF0047190Courtesy of FORD MOTOR CO.
    • For 2.3L engines, measure the resistance between starter relay connector pin 86 circuit CBP21 (BU/GY) and ground.
      • Fig 26: Measuring Resistance
      GF0047191Courtesy of FORD MOTOR CO.
    • For 3.0L and 4.0L engines, measure the resistance between starter relay connector pin 85 circuit CBP21 (BU/GY) and ground.
    • Is the resistance greater than 10,000 ohms? 
    1. YES  : Go to  A20.
    2. NO  : REPAIR circuit CBP21 (BU/GY) for a short to ground. TEST the system for normal operation.
  20. A20 CHECK THE TR SENSOR INPUT 
    • Key in START position.
      • Fig 27: Measuring Voltage
      GF0009547Courtesy of FORD MOTOR CO.
    • Measure the voltage at TR sensor connector C167-12, circuit CBP 21 (BU/GY).
    • Is the voltage greater than 10 volts? 
    1. YES  : Go to  A21.
    2. NO  : Go to  A22.
  21. A21 CHECK THE TR SENSOR ADJUSTMENT 
    1. YES  : INSTALL a new TR sensor. CHECK the system for normal operation.
    2. NO  : ADJUST the TR sensor. REFER to AUTOMATIC TRANSMISSION - 5R44E & 5R55E article. TEST the system for normal operation.
  22. A22 CHECK SJB FUSE 21 (5A) 
    • Disconnect: SJB Fuse 21 (5A)
    • Check fuse: SJB Fuse 21 (5A)
    • Is SJB fuse 21 (5A) OK? 
    1. YES  : Go to  A23.
    2. NO  : Go to  A24.
  23. A23 CHECK THE INPUT TO SJB FUSE 21 (5A) 
    • Key in START position.
      • Fig 28: Measuring Voltage
      GF0047192Courtesy of FORD MOTOR CO.
    • Measure the voltage at the input cavity of SJB fuse 21 (5A) circuit CBP21 (BU/GY).
    • Is the voltage reading greater than 10 volts? 
    1. YES  : REPAIR circuit CBP21 (BU/GY) for an open. TEST the system for normal operation.
    2. NO  : Go to  A25.
  24. A24 CHECK CIRCUIT CBP21 (BU/GY) FOR A SHORT TO GROUND 
    • Key in OFF position.
      • Fig 29: Measuring Resistance
      GF0047193Courtesy of FORD MOTOR CO.
    • Measure the resistance between the output cavity of fuse junction panel fuse 21 (5A) circuit CBP21 (BU/GY) and ground.
    • Is the resistance greater than 10,000 ohms? 
    1. YES  : INSTALL a new SJB fuse 21 (5A). TEST the system for normal operation.
    2. NO  : REPAIR circuit CBP21 (BU/GY) for a short to ground. INSTALL a new SJB fuse 21 (5A). TEST the system for normal operation.
  25. A25 CHECK THE SUPPLY TO THE IGNITION SWITCH 
    • Disconnect: Ignition Switch C213
      • Fig 30: Measuring Voltage
      GF0009550Courtesy of FORD MOTOR CO.
    • Measure the voltage at ignition switch connector pin C250-7, circuit SB09 (RD).
    • Is the voltage reading greater than 10 volts? 
    1. YES  : Go to  A26.
    2. NO  : REPAIR circuit SBB09 (RD) for an open. TEST the system for normal operation.
  26. A26 CHECK CIRCUIT CDC35 (BU/WH) FOR AN OPEN 
      Fig 31: Measuring Resistance
      GF0047194Courtesy of FORD MOTOR CO.
    • Measure the resistance of circuit CDC35 (BU/WH) between ignition switch connector pin C250-5 and input cavity of SJB fuse 21 (5A).
    • Is the resistance reading 5 ohms or less? 
    1. YES  : INSTALL a new ignition switch. REFER to STEERING COLUMN SWITCHES article. TEST the system for normal operation.
    2. NO  : REPAIR circuit CDC35 (BU/WH) for an open. TEST the system for normal operation.

Pinpoint Test B: Unusual Starter Noise 

Normal Operation 

Under normal operation, voltage from the battery junction box (BJB) is supplied to the ignition switch through circuit SBB09 (RD). When the ignition switch is placed in the START position, voltage is supplied through circuit CDC35 (BU/WH) to smart junction box (SJB) fuse 21 (5A).

For automatic transmission equipped vehicles, voltage is supplied from SJB fuse 21 (5A) to the digital transmission range (TR) sensor through circuit CBP 21 (BU/GY) and then to the starter relay coil through circuit CET 40 (GN/OG). A ground is supplied through circuit CDC12 (YE) and the PCM.

For manual transmission equipped vehicles, voltage is supplied from SJB fuse 21 (5A) to the starter relay coil through circuit CBP 21 (BU/GY). A ground is supplied through circuit CDC12 (YE) and the PCM. The PCM will not supply ground to the starter relay coil unless the clutch is depressed, grounding the clutch pedal position bottom of travel input to the PCM on circuit CDC 36 (GN/BN).

When the starter relay coil is energized, the relay contacts close. This allows power to be supplied from BJB fuse 7 (40A) through circuit SBB07 (WH/RD) to the relay contacts. Power 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. It also closes the solenoid contacts allowing power directly from the battery to energize the starter motor to start the engine.

This pinpoint test is designed to diagnose the following:

PINPOINT TEST B: UNUSUAL STARTER NOISE 

  1. B1 CHECK THE STARTER MOUNTING 
    • Inspect the starter mounting bolts and brackets for looseness.
    • Is the starter motor mounted correctly? 
    1. YES  : Go to  B2.
    2. NO  : INSTALL the starter motor correctly. REFER to Starter Motor - 2.3L , Starter Motor - 3.0L  or Starter Motor - 4.0L . TEST the system for normal operation.
  2. B2 CHECK FOR ENGINE NOISE 
    • Key in OFF position.
      • Fig 32: Inspecting Starter Motor
      GF0000678Courtesy of FORD MOTOR CO.
    • 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? 
    1. YES  : Go to  B3.
    2. NO  : REFER to ENGINE SYSTEM - GENERAL INFORMATION article to continue the diagnosis.
  3. B3 CHECK FOR UNUSUAL WEAR 
    1. YES  : INSTALL a new ring gear. EXAMINE the starter pinion teeth. If damaged, INSTALL a new starter motor. TEST the system for normal operation.
    2. NO  : INSTALL a new starter motor. TEST the system for normal operation.
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