Component Tests and General Diagnostics
Starter Circuit TroubleshootingNOTE:
- Air temperature must be between 59° and 100 °F (15° and 38 °C) during this procedure.
- After this inspection, or any subsequent repair, reset the engine control module (ECM) to clear any diagnostic trouble codes (DTCs).
- The battery must be in good condition and fully charged.
Recommended Procedure:
- Use a starter system tester.
- Connect and operate the equipment in accordance with the manufacturer's instructions.
Alternate Procedure
1. Hook up the following equipment;
- Ammeter, 0 - 400 A
- Voltmeter, 0 - 20 V (accurate within 0.1 V)
- Tachometer, 0 - 1,200 rpm
2. Remove the No. 2 (15 A) fuse from the under-dash fuse/relay box.
3. Turn the ignition switch ON (II) with the clutch pedal pressed, and press the engine start switch.
Did the starter crank the engine normally?
YES - The starting system is OK.
NO - Go to step 4.
4. Check the battery condition. Check electrical connections at the battery, the negative battery cable to body, engine ground cables, and the starter for looseness and corrosion. Then try starting the engine again.
Did the starter crank the engine?
YES - Repairing the loose connection fixed the problem. The starting system is now OK.
NO - If the starter will not crank the engine at all, go to step 5. If it cranks the engine erratically or too slowly, go to step 7. If it won't disengage from the flywheel ring gear when you release the switch, check for the following until you find the cause.
- Solenoid plunger and switch malfunction
- Dirty drive gear or damaged overrunning clutch
5. Make sure the transmission is in Neutral, then disconnect the BLK/WHT wire (A) from the starter solenoid (B). Connect a jumper wire from the battery positive terminal to the solenoid terminal.
Did the starter crank the engine?
YES - Go to step 6.
NO - Remove the starter, and repair or replace as necessary.
6. Check the following wires in the order listed until you find the open circuit.
- Between the ignition switch and the starter cut relay.
- Between the ignition switch and the start switch.
- Between the start switch and the starter cut relay.
- Between the starter cut relay and the clutch interlock switch.
- Between the clutch interlock switch and body ground.
- Between the starter cut relay and the starter.
- Check the ignition switch, the start switch, the clutch interlock switch, and those connectors.
- Substitute a known-good starter cut relay.
7. Check the cranking voltage and current draw.
Is the cranking voltage greater than or equal to 8.7 V and the current draw less than or equal to 380 A?
YES - Go to step 8.
NO - Replace the starter, or remove and disassemble it, and check for the following until you find the cause.
- Open circuit in starter armature commutator segments
- Drag in the starter armature
- Shorted armature winding
- Excessive drag in the engine
8. Check engine speed during cranking.
Is the engine speed above 100 rpm?
YES - Go to step 9.
NO - Replace the starter, or remove and disassemble it, and check for the following until you find the cause.
- Excessively worn starter brushes
- Open circuit in commutator brushes
- Dirty or damaged helical spline or drive gear
- Faulty drive gear clutch
9. Remove the starter, and inspect its drive gear and the flywheel ring gear for damage. Replace any damaged parts.
10. Reinstall the No. 2 (15 A) fuse in the under-dash fuse/relay box.