DESCRIPTION
An electrically operated engine starting system is standard factory-installed equipment on this model. The starting system is designed to provide the vehicle operator with a convenient, efficient and reliable means of cranking and starting the internal combustion engine used to power the vehicle and all of its accessory systems from within the safe and secure confines of the passenger compartment. See the owner's manual in the vehicle glove box for more information and instructions on the recommended use and operation of the factory-installed starting system.
The starting system consists of the following components
- Battery
- Starter Motor
- Starter Solenoid
- Ignition Switch
- Wire harnesses and connections (including the battery cables).
This information provides complete service information for the starter motor. Complete service information for the other starting system components can be located as follows
- «(Refer to ELECTRICAL/BATTERY SYSTEM - DESCRIPTION)»(ref-250654-S13023201462007031500000) .
- «(Refer to IGNITION SYSTEM - ELECTRICAL DIAGNOSTICS - DESCRIPTION)»(ref-250655-S16061483042007031500000) for Electrical Diagnostics or «(Refer to IGNITION SYSTEM - SERVICE INFORMATION - DESCRIPTION)»(ref-250651-S05607218822007031500000) for Service Information .
- Refer to «SYSTEM WIRING DIAGRAMS»(ref-172302) for complete service information and circuit diagrams for the starting system wiring components.
The battery, starting, and charging systems in the vehicle operate with one another, and must be tested as a complete system. In order for the vehicle to start and charge properly, all of the components that are used in these systems must perform within specifications.
The diagnostic procedures used in each of these groups include the most basic conventional diagnostic methods, to the more sophisticated On-Board Diagnostics (OBD) built into the Powertrain Control Module (PCM). Use of an induction-type milliampere ammeter, volt/ohmmeter, battery charger, carbon pile rheostat (load tester), and 12-volt test lamp may be required.
All OBD-sensed systems are monitored by the PCM. Each monitored circuit is assigned a Diagnostic Trouble Code (DTC). The PCM will store a DTC in electronic memory for any failure it detects. Refer to On-Board Diagnostic Test For Charging System in CHARGING SYSTEM for more information.
OPERATION
The starting system components form two separate circuits. A high-amperage feed circuit that feeds the starter motor between 150 and 350 amperes, and a low-amperage control circuit that operates on less than 20 amperes. The high-amperage feed circuit components include the battery, the battery cables, the contact disc portion of the starter solenoid, and the starter motor. The low-amperage control circuit components include the ignition switch, the pulse module, the electromagnetic windings of the starter solenoid, and the connecting wire harness components.
Battery voltage is supplied through the low-amperage control circuit to the pulse module when the ignition switch is turned to the momentary Start position. When the starter solenoid coil windings are energized, the solenoid pull-in coil pulls in the solenoid plunger. The solenoid plunger pulls the shift lever in the starter motor. This engages the starter overrunning clutch and pinion gear with the starter ring gear on the flywheel.
As the solenoid plunger reaches the end of its travel, the solenoid contact disc completes the high-amperage starter feed circuit and energizes the solenoid plunger hold-in coil. Current now flows between the solenoid battery terminal and the starter motor, energizing the starter.
When the solenoid plunger hold-in coil is de-energized, the solenoid plunger return spring returns the plunger to its relaxed position. This causes the contact disc to open the starter feed circuit, and the shift lever to disengage the overrunning clutch and pinion gear from the starter ring gear.
Once the engine starts, the pulse module prevents starter motor damage by only allowing the starter to be engaged until the engine is running. Once the engine fires and achieves an RPM threshold that the Powertrain Control Module (PCM) defines as "engine running", the starter motor is automatically disengaged by the PCM through the pulse module. The pulse module further prevents starter motor damage by not allowing the starter motor to be engaged if the engine is already running.
The battery, starting, and charging systems operate with one another, and must be tested as a complete system. In order for the vehicle to start and charge properly, all of the components involved in these systems must perform within specifications.
The diagnostic procedures used in this information includes most conventional diagnostic methods. The use of an induction-type milliampere ammeter, volt/ohmmeter, battery charger, carbon pile rheostat (load tester), and 12-volt test lamp may be required.
| CONDITION | POSSIBLE CAUSE | CORRECTION |
|---|---|---|
| STARTER FAILS TO OPERATE. | 1. Battery discharged or faulty. | 1. Refer to BATTERY SYSTEM . Charge or replace the battery, if required. |
| 2. Starting circuit wiring faulty. | 2. Refer to SYSTEM WIRING DIAGRAMS . Test and repair the starter feed and/or control circuits, if required. | |
| 3. Ignition switch faulty. | 3. Refer to Ignition Switch and Key Lock Cylinder in COLUMN . Replace the ignition switch, if required. | |
| 4. Park/Neutral position switch faulty or misadjusted. | 4. Refer to Park/Neutral Position Switch in A/T & M/T - SERVICE INFORMATION . Replace the park/neutral position switch, if required. | |
| 5. Starter solenoid faulty. | 5. Refer to STARTER MOTOR . Replace the starter motor assembly, if required. | |
| 6. Starter motor faulty. | 6. If all other starting system components and circuits test OK, replace the starter motor assembly. | |
| STARTER ENGAGES, FAILS TO TURN ENGINE. | 1. Battery discharged or faulty. | 1. Refer to BATTERY SYSTEM . Charge or replace the battery, if required. |
| 2. Starting circuit wiring faulty. | 2. Refer to SYSTEM WIRING DIAGRAMS . Test and repair the starter feed and/or control circuits, if required. | |
| 3. Starter motor faulty. | 3. If all other starting system components and circuits test OK, replace the starter motor assembly. | |
| 4. Engine seized. | 4. Refer to appropriate Engine SERVICE INFORMATION . | |
| STARTER ENGAGES, SPINS OUT BEFORE ENGINE STARTS. | 1. Starter ring gear faulty. | 1. Refer to REMOVAL and INSTALLATION . Remove the starter motor to inspect the starter ring gear. Replace the starter ring gear, if required. |
| 2. Starter motor faulty. | 2. If all other starting system components and circuits test OK, replace the starter motor assembly. | |
| STARTER DOES NOT DISENGAGE. | 1. Starter motor improperly installed. | 1. Refer to REMOVAL and INSTALLATION . Tighten the starter mounting hardware to the correct tightness specifications. |
| 2. Ignition switch faulty. | 2. Refer to Ignition Switch and Key Lock Cylinder in COLUMN . Replace the ignition switch, if required. | |
| 3. Starter motor faulty. | 3. If all other starting system components and circuits test OK, replace the starter motor assembly. |
STARTING SYSTEM DIAGNOSIS
The starter motor is equipped with a planetary gear reduction system. The planetary gear reduction system consists of a gear that is integral to the output end of the electric motor armature shaft that is in continual engagement with a larger gear that is splined to the input end of the starter pinion gear shaft. This feature makes it possible to reduce the dimensions of the starter. At the same time, it allows higher armature rotational speed and delivers increased torque through the starter pinion gear to the starter ring gear.
The starter motor is activated by an integral heavy duty starter solenoid switch mounted to the overrunning clutch housing. This electromechanical switch connects and disconnects the feed of battery voltage to the starter motor and actuates a shift fork that engages and disengages the starter pinion gear with the starter ring gear.