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
Under normal operation, the Battery Junction Box (BJB) supplies constant power to the starter relay on circuit 32 (RD/LB) through fuse 105 (30A). When the key is placed in the START position with the vehicle in PARK or NEUTRAL, the digital Transmission Range (TR) sensor provides power on circuit 33 (WH/PK) and the PCM provides ground on circuit 3405 (GY/RD), activating the starter motor. On police vehicles, the digital TR sensor provides power on circuit 33 (WH/PK) and ground through circuit 57 (BK), activating the starter motor. This allows power to be supplied from the starter motor relay contacts which then flows through circuit 113 (YE/LB) 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 close the solenoid contacts, allowing power directly from the battery through circuit 2037 (RD) to the starter motor to start the engine.
This pinpoint test is intended to diagnose the following:
- Battery
- Starter motor
- Starter motor solenoid relay
- Starter motor relay
- Ignition switch
- PCM
- Fuse
- Anti-theft system
- Circuitry
PINPOINT TEST A: THE ENGINE DOES NOT CRANK
-------------------------------------------------
A1 CHECK THE BATTERY
- Check the battery condition and state of charge. Refer to Diagnosis and Testing in Battery, Mounting and Cables Testing and Inspection.
- Is the battery OK?
Yes
GO to A2.
No
CHARGE or INSTALL a new battery as necessary. REFER to Battery, Mounting and Cables Battery. TEST the system for normal operation.
-------------------------------------------------
A2 CHECK FOR PATS OR PCM DTCs
- Using the DTCs retrieved in Inspection and Verification, check for Passive Anti-Theft System (PATS) and PCM DTCs.
- Were any PATS or PCM DTCs retrieved?
Yes
REFER to the DTC Chart in Multifunction Electronic Modules Testing and Inspection.
No
GO to A3.
-------------------------------------------------
A3 CHECK THE BATTERY GROUND CABLE
- WARNING: Before servicing a vehicle equipped with a fire suppression system, depower the system by following the procedure in Fire Suppression System. Failure to follow the instructions may result in serious personal injury Procedures.
- With the vehicle in NEUTRAL, position it on a hoist. Refer to Jacking and Lifting Service and Repair.
- 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. REFER to Battery, Mounting and Cables Service and Repair. TEST the system for normal operation. If equipped with a fire suppression system, GO to A21.
-------------------------------------------------
A4 CHECK THE STARTER MOTOR GROUND
- Measure the voltage between the battery positive 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. If equipped with a fire suppression system, GO to A21.
-------------------------------------------------
A5 CHECK THE POWER SUPPLY AT THE STARTER MOTOR
- Measure the voltage at starter motor solenoid C197A, circuit 2037 (RD) and ground.
- Is the voltage reading greater than 10 volts?
Yes
GO to A6.
No
INSTALL a new positive battery cable. REFER to Battery, Mounting and Cables Service and Repair. TEST the system for normal operation. If equipped with a fire suppression system, GO to A21.
-------------------------------------------------
A6 CHECK THE STARTER MOTOR
- Connect one end of a fused jumper wire to starter motor C197A, circuit 2037 (RD). Momentarily connect the other end of the jumper to starter motor C197B, circuit 113 (YE/LB).
- Does the starter motor engage and the engine crank?
Yes
GO to A7.
No
INSTALL a new starter motor. REFER to Starter Motor Service and Repair. TEST the system for normal operation. If equipped with a fire suppression system, GO to A21.
-------------------------------------------------
A7 CHECK START INPUT TO THE STARTER MOTOR
- Disconnect: Starter Motor Solenoid C197B.
- Measure the voltage at the starter motor solenoid C197B, circuit 113 (YE/LB) and ground, while holding the ignition switch to the START position.
- Is the voltage reading greater than 10 volts?
Yes
CLEAN the starter motor solenoid C197B stud and connector. CHECK the wiring and the starter motor for a loose or intermittent connection. TEST the system for normal operation. If equipped with a fire suppression system, GO to A21.
No
GO to A8.
-------------------------------------------------
A8 CHECK START INPUT TO THE STARTER RELAY
NOTICE: Use the correct probe adapter(s) when taking measurements. Failure to use the correct probe adapter(s) may damage the connector.
- Ignition OFF.
- Disconnect: BJB Starter Relay.
- Measure the voltage at the BJB starter relay pin 86, circuit 33 (WH/PK), while holding the ignition switch to the START position.
- Is the voltage reading greater than 10 volts?
Yes
GO to A9.
No
GO to A15.
-------------------------------------------------
A9 CHECK THE BATTERY SUPPLY TO THE STARTER RELAY
- Ignition OFF.
- Measure the voltage at the BJB starter relay pin 30, circuit 32 (RD/LB) and ground.
- Is the voltage reading greater than 10 volts?
Yes
For police vehicles, GO to A10. For all other vehicles, GO to A11.
No
VERIFY BJB fuse 105 (30 A) is OK. If OK, REPAIR the circuit 32 (RD/LB). TEST the system for normal operation. If not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short. If equipped with a fire suppression system, GO to A21. Diagrams By Number
-------------------------------------------------
A10 CHECK THE STARTER RELAY GROUND
- On police vehicles, measure the resistance between BJB starter relay pin 85, circuit 57 (BK) and ground.
- Is the resistance reading less than 5 ohms?
Yes
GO to A12.
No
REPAIR circuit 57 (BK) for an open. TEST the system for normal operation. If equipped with a fire suppression system, GO to A21.
-------------------------------------------------
A11 CHECK CIRCUIT 3405 (GY/RD) FOR AN OPEN
- Disconnect: PCM C175B.
- Measure the resistance between BJB starter relay pin 85, circuit 3405 (GY/RD) and PCM C175B-2, circuit 3405 (GY/RD), harness side.
- Is the resistance reading less than 5 ohms?
Yes
GO to A12.
No
REPAIR circuit 3405 (GY/RD). TEST the system for normal operation. If equipped with a fire suppression system, GO to A21.
-------------------------------------------------
A12 CHECK CIRCUIT 113 (YE/LB) FOR A SHORT TO GROUND
- Disconnect: Starter Motor Solenoid 197B.
- Measure the resistance between BJB starter relay pin 87, circuit 113 (YE/LB) and ground.
- Is the resistance reading less than 10,000 ohms?
Yes
REPAIR circuit 113 (YE/LB) for a short to ground. TEST the system for normal operation. If equipped with a fire suppression system, GO to A21.
No
GO to A13.
-------------------------------------------------
A13 CHECK CIRCUIT 113 (YE/LB) FOR AN OPEN
- Measure the resistance between BJB starter relay pin 87, circuit 113 (YE/LB) and starter motor solenoid C197B, circuit 113 (YE/LB).
- Is the resistance reading less than 5 ohms?
Yes
GO to A14.
No
REPAIR circuit 113 (YE/LB) for an open. TEST the system for normal operation. If equipped with a fire suppression system, GO to A21.
-------------------------------------------------
A14 CHECK THE STARTER MOTOR RELAY
- Carry out the Starter Motor Relay Component Test.
Refer to Starter Relay for component testing.
- Did the starter motor relay pass the component test?
Yes
INSTALL a new BJB. TEST the system for normal operation. If equipped with a fire suppression system, GO to A21.
No
INSTALL a new starter motor relay. TEST the system for normal operation. If equipped with a fire suppression system, GO to A21.
-------------------------------------------------
A15 CHECK FOR VOLTAGE TO THE IGNITION SWITCH
- Disconnect: Ignition Switch C250.
- Measure the voltage at ignition switch C250-9, circuit 1050 (LG/VT), harness side and ground.
- Is the voltage reading greater than 10 volts?
Yes
GO to A16.
No
VERIFY BJB fuse 1 (30 A) is OK. If OK, REPAIR the circuit 1050 (LG/VT). TEST the system for normal operation. If not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short. If equipped with a fire suppression system, GO to A21. Diagrams By Number
-------------------------------------------------
A16 CHECK THE IGNITION SWITCH
- Carry out the Ignition Switch Component Test.
Refer to Ignition Switch for component testing.
- Did the ignition switch pass the component test?
Yes
GO to A17.
No
INSTALL a new ignition switch. REFER to Steering Column Switches Ignition Switch. TEST the system for normal operation. If equipped with a fire suppression system, GO to A21.
-------------------------------------------------
A17 CHECK FOR VOLTAGE TO CJB FUSE 1 (10A)
- Disconnect: Central Junction Box (CJB) fuse 1 (10A).
- Measure the voltage at the CJB input cavity of fuse 1 (10A), circuit 1522 (DG) and ground with the ignition switch in the START position.
- Is the voltage reading greater than 10 volts?
Yes
GO to A18.
No
VERIFY CJB fuse 1 (10 A) is OK. If OK, REPAIR circuit 1522 (DG). TEST the system for normal operation. If not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short. If equipped with a fire suppression system, GO to A21. Diagrams By Number
-------------------------------------------------
A18 CHECK FOR VOLTAGE AT THE DIGITAL TR SENSOR
- Disconnect: Digital Transmission Range (TR) Sensor C167.
- Measure the voltage between the digital TR sensor C167-12, circuit 262 (BN/PK), harness side and ground with the ignition switch in the START position.
- Is the voltage reading greater than 10 volts?
Yes
GO to A19.
No
REPAIR circuit 262 (BN/PK). TEST the system for normal operation. If equipped with a fire suppression system, GO to A21.
-------------------------------------------------
A19 CHECK CIRCUIT 33 (WH/PK) FOR AN OPEN
- Measure the resistance between BJB starter relay pin 86, circuit 33 (WH/PK), harness side and digital TR sensor C167-10, circuit 33 (WH/PK), harness side.
- Is the resistance reading less than 5 ohms?
Yes
REFER to Automatic Transaxle/Transmission External Controls Selector Lever Cable Adjustment, Selector Lever Cable Adjustment. If adjustment is OK, GO to A20.
No
REPAIR circuit 33 (WH/PK) for an open. TEST the system for normal operation. If equipped with a fire suppression system, GO to A21.
-------------------------------------------------
A20 CHECK THE TR SENSOR
- NOTICE: Do not pry on connector. This will damage the connector and result in a transmission concern.
- Measure the resistance between digital TR sensor pin 10 and pin 12, component side, with the selector lever in PARK and then NEUTRAL.
- Are all resistances less than 5 ohms?
Yes
INSTALL a new BJB. TEST the system for normal operation. If equipped with a fire suppression system, GO to A21.
No
INSTALL a new digital TR sensor. REFER to Automatic Transaxle/Transmission - 4R70E/4R75E Service and Repair. TEST the system for normal operation. If equipped with a fire suppression system, GO to A21.
-------------------------------------------------
A21 REPOWER THE FIRE SUPPRESSION SYSTEM
- WARNING: If the vehicle is equipped with a fire suppression system, repower the system. For important safety warnings and procedures, refer to Fire Suppression System. Failure to follow these instructions may result in serious personal injury Description and Operation.
- Verify that the fire suppression system is repowered. Refer to Fire Suppression System Procedures.
- Is the fire suppression system repowered?
Yes
Fire suppression system repowering is complete.
No
REFER to Fire Suppression System Testing and Inspection for diagnosis and testing of the fire suppression system.
-------------------------------------------------