Cranking System Symptom Diagnosis
Possible symptoms of starting system trouble would be as follows:
- Starting motor does not run (or runs slowly).
- Starting motor runs but fails to crank engine.
- Abnormal noise is heard.
Proper diagnosis must be made to determine exactly where the cause of each trouble lies in battery, wiring harness, starting motor (including magnetic switch) or engine.
Do not remove starting motor just because starting motor does not run. Check the following items and narrow down scope of possible causes.
- Condition of trouble
- Tightness of battery terminals (including ground cable connection on engine) and starting motor terminals
- Discharge of battery
- Mounting of starting motor
POSSIBLE CAUSE REFERENCE
| Condition | Possible Cause | Action |
|---|---|---|
| Starting motor not running (No operating sound of magnetic switch) | Malfunction of Shift switch (4 A/T model and 5 A/T model) | Check shift switch
. 4 A/T model: See TRANSMISSION RANGE SENSOR INSPECTION AND ADJUSTMENT 5 A/T model: See |
| Malfunction of clutch switch (5 M/T model) | Check clutch switch . See CLUTCH PEDAL POSITION (CPP) SWITCH (FOR 4WD CONTROL MODULE) INSPECTION AND ADJUSTMENT | |
| Battery voltage is too low | Check battery . See BATTERY INSPECTION . | |
| Charging faulty due to deteriorated battery | Replace battery . See BATTERY REMOVAL AND INSTALLATION . | |
| Poor battery terminal connection | Check terminal connection or replace battery . See BATTERY REMOVAL AND INSTALLATION | |
| Poor ground cable connection | Tighten ground cable . | |
| Fuse blown | Replace fuse . | |
| Ignition switch faulty | Check ignition switch , see IGNITION SWITCH INSPECTION . | |
| Magnetic switch faulty | Check magnetic switch , see STARTING MOTOR INSPECTION . | |
| Poor magnetic switch lead wire connector connection | Check connector connection . | |
| Open-circuit between ignition switch and magnetic switch | Repair circuit . | |
| Open-circuit in pull-in coil | Check pull-in coil circuit . See STARTING MOTOR INSPECTION . | |
| Brushes and/or brush springs faulty | Check brushes and brush springs . See STARTING MOTOR INSPECTION . | |
| Poor sliding of plunger and/or pinion | Check plunger and pinion . See STARTING MOTOR INSPECTION . | |
| Starting motor control relay faulty | Check starting motor control relay . See STARTING MOTOR CONTROL RELAY INSPECTION . | |
| ECM and its circuit faulty | Check ECM and its circuit
. See INSPECTION OF ECM AND ITS CIRCUITS . |
|
| Starting motor not running (Operating sound of magnetic switch heard) | Battery voltage is too low | Check battery . See BATTERY INSPECTION . |
| Charging faulty due to deteriorated battery | Replace battery . See BATTERY REMOVAL AND INSTALLATION . | |
| Poor battery terminal connection | Check terminal connection or replace battery . See BATTERY REMOVAL AND INSTALLATION . | |
| Poor ground terminal connection | Tighten ground cable . | |
| Magnetic switch faulty | Check magnetic switch . See STARTING MOTOR INSPECTION . | |
| Brushes and/or brush springs faulty | Check brushes and brush springs . See STARTING MOTOR INSPECTION . | |
| Brush holder faulty | Check brush holder . See STARTING MOTOR INSPECTION . | |
| Commutator burnt | Check commutator . See STARTING MOTOR INSPECTION . | |
| Short-circuit between commutator and armature | Check commutator . See STARTING MOTOR INSPECTION . | |
| Ignition switch faulty | Check ignition switch . See IGNITION SWITCH INSPECTION . | |
| Poor starting motor cable connection | Check starting motor cable connection . See STARTING MOTOR REMOVAL AND INSTALLATION . | |
| Open circuit between Ignition switch and magnetic switch | Repair circuit . | |
| Open circuit in pull-in coil | Check pull-in coil circuit . See STARTING MOTOR INSPECTION . | |
| Crank shaft rotation obstructed | Repair engine assembly . | |
| Starting motor running but too slowly (small torque) (If battery and wiring are satisfactory, inspect starting motor) | Magnetic switch faulty | Check magnetic switch . See STARTING MOTOR INSPECTION . |
| Short-circuit between commutator and armature | Check commutator . See STARTING MOTOR INSPECTION . | |
| Commutator burnt | Check commutator . See STARTING MOTOR INSPECTION . | |
| Brushes and/or brush springs faulty | Check brushes and brush springs . See STARTING MOTOR INSPECTION . | |
| Brush holder faulty | Check brush holder . See STARTING MOTOR INSPECTION . | |
| Rear bracket bush faulty | Check rear bracket bush . See STARTING MOTOR INSPECTION . | |
| Starting motor running, but not cranking engine | Worn pinion tip | Replace over-running clutch . See STARTING MOTOR COMPONENTS . |
| Poor sliding of over-running clutch | Check over-running clutch . See STARTING MOTOR INSPECTION . | |
| Over-running clutch slipping | Replace over-running clutch . See STARTING MOTOR COMPONENTS . | |
| Worn teeth of ring gear | Replace flywheel (M/T model) or drive plate (A/T model)
. See FLYWHEEL/DRIVE PLATE REMOVAL AND INSTALLATION . |
|
| Noise | Abnormally worn bush | Replace bush . See STARTING MOTOR COMPONENTS . |
| Worn teeth of pinion | Replace over-running clutch . See STARTING MOTOR COMPONENTS . | |
| Worn teeth of ring gear | Replace flywheel (M/T model) or drive plate (A/T model)
. See FLYWHEEL/DRIVE PLATE REMOVAL AND INSTALLATION . |