Pinpoint Test A: The Engine Does Not Crank
Starting System
Pinpoint Tests
Pinpoint Test A: The Engine Does Not Crank
Refer to Wiring Diagram Set 20, Starting System for schematic and connector information. Diagrams By Number
Normal Operation
In normal operation, voltage from the Bussed Electrical Center (BEC) is supplied to the ignition switch through circuit 1050 (LG/PK). When the ignition switch is placed in the START position, voltage is supplied through circuit 1522 (DG) to the Smart Junction Box (SJB).
For automatic transmission equipped vehicles, voltage is supplied from the SJB on circuit 32 (RD/LB) to the BEC, from the BEC power is supplied to the Transmission Range (TR) sensor through circuit 33 (WH/PK). In PARK or NEUTRAL, voltage is supplied from the TR sensor through circuit 33 (WH/PK) to the starter relay coil located in the BEC. The starter relay coil is supplied ground from the PCM through circuit 1419 (LG/YE).
For manual transmission equipped vehicles, when the clutch pedal is depressed, the Clutch Pedal Position (CPP) supplies a ground to the PCM through circuit 92 (LB/YE). The starter relay coil is supplied ground from the PCM through circuit 1419 (LG/YE). Voltage is supplied to the starter relay coil located in the BEC through circuit 33 (WH/PK).
When the starter relay is energized, voltage supplied to the relay switch is sent to the starter motor solenoid through circuit 113 (YE/LB). Battery voltage is supplied to the starter motor through circuit 2037 (RD) at all times.
This pinpoint test is intended to diagnose the following:
- Fuse(s)
- Battery
- Anti-theft system
- Starter relay
- Ignition switch
- Circuitry
- PCM
PINPOINT TEST A: THE ENGINE DOES NOT CRANK
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A1 CHECK THE BATTERY
- Check the battery condition and charge. Refer to Battery.
- Is the battery OK?
Yes
GO to A2.
No
CHARGE or INSTALL a new battery. TEST the system for normal operation.
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A2 CHECK PCM FOR DTCs
- Using the DTCs retrieved in Inspection and Verification, check for PCM DTCs.
- Were any PCM DTCs retrieved?
Yes
If PCM DTC P1260 is retrieved, REFER to Antitheft and Alarm Systems. All other PCM DTCs, REFER to Computers and Control Systems Information.
No
For automatic transmission, GO to A3. For manual transmission, GO to A4.
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A3 CHECK THE PCM AUTOMATIC TR SENSOR PID
- Connect the scan tool.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: DataLogger - PCM.
- While observing the TR PID, place the vehicle in PARK and then NEUTRAL.
- Does the PID match the gear selection?
Yes
GO to A5.
No
GO to Transmission Control Systems to diagnose the TR sensor. Testing and Inspection
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A4 CHECK THE PCM CLUTCH PEDAL AT OR NEAR BOTTOM OF TRAVEL (CPP_ BOT) PID
- Connect the scan tool.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: DataLogger - PCM.
- While observing the CPP_ BOT) PID, fully disengage the clutch.
- Does the PID change from NO to YES?
Yes
GO to A5.
No
GO to A19.
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A5 CHECK THE BATTERY GROUND CABLE
- Measure the voltage between the positive battery post and the battery ground cable connection on the engine.
- Is the voltage greater than 10 volts?
No
INSTALL a new battery ground cable. TEST the system for normal operation.
Yes
GO to A6.
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A6 CHECK THE STARTER MOTOR GROUND
- Measure the voltage between the positive battery post and the starter motor case.
- Is the voltage greater than 10 volts?
Yes
GO to A7.
No
CLEAN the starter motor mounting flange and make sure the starter motor is correctly mounted. TEST the system for normal operation.
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A7 CHECK THE POWER SUPPLY TO THE STARTER MOTOR
- Measure the voltage between starter motor B-terminal and ground.
- Is the voltage greater than 10 volts?
Yes
GO to A8.
No
INSTALL a new positive battery cable. TEST the system for normal operation.
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A8 CHECK THE STARTER MOTOR SOLENOID OPERATION
- Connect a fused jumper wire to the B-terminal of the starter motor. Momentarily connect the other lead of the fused jumper wire to the starter motor S-terminal.
- Did the starter motor engage and the engine crank?
Yes
GO to A9.
No
INSTALL a new starter motor. REFER to Starter Motor - 4.0L SOHC Service and Repair or Starter Motor - 4.6L (3V) Service and Repair or Starter Motor - 5.4L (4V) Service and Repair. TEST the system for normal operation.
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A9 CHECK THE START INPUT TO THE STARTER MOTOR
NOTE: Depress clutch pedal for manual transmission.
- Disconnect: Starter Motor S-Terminal C197B.
- Measure the voltage between starter motor S-terminal connector C197B, circuit 113 (YE/LB), and ground, while holding the ignition switch in the START position.
- Is the voltage greater than 10 volts in START?
Yes
CLEAN the starter motor S-terminal and connector. CHECK the wiring and the starter motor for a loose connection. TEST the system for normal operation.
No
GO to A10.
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A10 CHECK CIRCUIT 113 (YE/LB) FOR AN OPEN
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
- Measure the resistance between BEC starter relay, circuit 113 (YE/LB), and starter motor S-terminal connector C197B, circuit 113 (YE/LB).
- Is the resistance less than 5 ohms?
Yes
GO to A11.
No
REPAIR circuit 113 (YE/LB) for an open. TEST the system for normal operation.
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A11 CHECK THE BATTERY SUPPLY TO THE STARTER RELAY
- Measure the voltage between BEC starter relay, circuit 2037 (RD) and ground.
- Is the voltage greater than 10 volts?
Yes
GO to A13.
No
GO to A12.
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A12 CHECK THE BATTERY SUPPLY TO THE BEC
- Disconnect: BEC Connector 1035E.
- Measure the voltage between BEC C1035E-1, circuit 2037 (RD) and ground.
- Is the voltage greater than 10 volts?
Yes
VERIFY BEC fuse 4 (30 A) is OK. If not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short. If OK, REPLACE the BEC. TEST the system for normal operation.
No
REPAIR circuit 2037 (RD) for an open. TEST the system for normal operation.
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A13 CHECK THE START INPUT TO THE STARTER RELAY
- Disconnect: Starter Relay.
- Measure the voltage between BEC starter relay, circuit 33 (WH/PK) and ground, while holding the ignition switch in the START position.
- Is the voltage greater than 10 volts?
Yes
GO to A17.
No
GO to A14.
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A14 CHECK THE START INPUT VOLTAGE TO THE BEC
- Disconnect: BEC C1035B.
- Measure the voltage between BEC C1035B-E10, circuit 33 (WH/PK) and ground, while holding the ignition switch in the START position.
- Is the voltage greater than 10 volts?
Yes
REPLACE the BEC. TEST the system for normal operation.
No
GO to A15.
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A15 CHECK THE POWER SUPPLY TO THE IGNITION SWITCH
- Disconnect: Ignition Switch C250.
- Measure the voltage between ignition switch C250-4, circuit 1050 (LG/VT) and ground.
- Is the voltage greater than 10 volts?
Yes
GO to A16.
No
VERIFY BEC fuse 68 (20 A) is OK. If OK, REPAIR circuit 1050 (LG/VT) for an open. TEST the system for normal operation. If not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short.
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A16 CHECK CIRCUITS 1522 (DG) AND 33 (WH/PK) FOR AN OPEN
- Measure the resistance between ignition switch C250-7, circuit 1522 (DG) and BEC C1035B-E10, circuit 33 (WH/PK).
- Is the resistance less than 5 ohms?
Yes
CARRY OUT the Ignition Switch Component Test.
INSTALL a new ignition switch. TEST the system for normal operation.
No
VERIFY Smart Junction Box (SJB) fuse 21 (10 A) is OK. If OK, REPAIR circuit 1522 (DG) or circuit 33 (WH/PK) for an open. TEST the system for normal operation. If not OK, REFER to the Wiring
Diagrams to identify the possible causes of the circuit short.
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A17 CHECK THE GROUND SIGNAL TO THE STARTER RELAY
- Measure the voltage between BEC starter, circuit 1419 (LG/YE), and starter relay, circuit 33 (WH/PK), while holding the ignition switch in the START position, depress clutch pedal for manual transmission.
- Is the voltage greater than 10 volts?
Yes
CARRY OUT the Starter Motor Relay Component Test.
INSTALL a new starter motor relay. TEST the system for normal operation.
No
GO to A18.
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A18 CHECK CIRCUIT 1419 (LG/YE) FOR AN OPEN
- Disconnect: PCM C175B.
- Measure the resistance between BEC starter relay pin 85, circuit 1419 (LG/YE) and PCM C175B-2, circuit 1419 (LG/YE).
- Is the resistance less than 5 ohms?
Yes
INSTALL a new PCM. TEST the system for normal operation.
No
REPAIR circuit 1419 (LG/YE) for an open. TEST the system for normal operation.
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A19 CHECK CIRCUIT 92 (LB/YE) FOR AN OPEN
- Disconnect: PCM C175B and CPP Switch C257.
- Measure the resistance between CPP switch C257-1, circuit 92 (LB/YE) and PCM C175B-33, circuit 92 (LB/YE).
- Is the resistance less than 5 ohms?
Yes
GO to A20.
No
REPAIR circuit 92 (LB/YE) for an open. TEST the system for normal operation.
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A20 CHECK CIRCUIT 1205 (BK) FOR AN OPEN
- Measure the resistance between CPP switch C257-2, circuit 1205 (BK) and ground.
- Is the resistance less than 5 ohms?
Yes
GO to A21.
No
REPAIR circuit 1205 (BK) for an open. TEST the system for normal operation.
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A21 CHECK CPP SWITCH
- Connect: CPP Switch C257.
- Measure the resistance between PCM C175B-33, circuit 92 (LB/YE) and ground, while depressing the clutch pedal.
- Is the resistance less than 5 ohms?
Yes
GO to A22.
No
INSTALL a new CPP switch. TEST the system for normal operation.
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A22 CHECK CIRCUIT 1419 (LG/YE) FOR AN OPEN
- Disconnect: PCM C175B.
- Measure the resistance between BEC starter relay, circuit 1419 (LG/YE) and PCM C175B-2, circuit 1419 (LG/YE).
- Is the resistance less than 5 ohms?
Yes
INSTALL a new PCM. TEST the system for normal operation.
No
REPAIR circuit 1419 (LG/YE) for an open. TEST the system for normal operation.
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