Starting System: Testing and Inspection
Starter Circuit TroubleshootingNOTE:
- Air temperature must be between 59 °and 100 °F (15 ° and 38 °C) during this procedure.
- Check that the fuel tank is not empty before doing this troubleshooting.
- Check the battery condition, and electrical connections at the battery and the starter for looseness and corrosion.
- After this test, or any subsequent repair, reset the Powertrain Control Module (PCM) to clear any Diagnostic Trouble Codes (DTCs).
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, 0-400A
- Voltmeter, 0 - 20 V (accurate within 0.1 V)
- Tachometer, 0 - 1,200 rpm
2. With the shift lever in N or P position, turn the ignition switch to START (III).
Did the starter crank the engine?
YES - The starting system is OK
NO - If the starter will not crank the engine at all, go to step 3. If it cranks the engine erratically or too slowly, go to step 25. If it won't disengage from the flywheel when you release the key, check for the following until you find the cause:
- Solenoid plunger and switch malfunction
- Dirty drive gear or damaged overrunning clutch
3. Make sure with the shift lever is in neutral position, then disconnect the BLK/YEL wire (A) from the starter solenoid (B), then connect a jumper wire from the battery positive terminal to the solenoid terminal.
Did the starter crank the engine?
YES - Go to step 5.
NO - Go to step 4.
4. Measure voltage between starter B terminal and body ground.
Is there battery voltage?
YES - Remove the starter, and diagnose its internal problems.
NO - Repair an open in the wire between the battery positive terminal and starter B terminal.
5. Check the No. 20 (40A) fuse in the under-hood fuse/relay box.
Is the fuse OK?
YES - Go to step 6.
NO - Go to step 19.
6. Do the ignition switch test.
Is the ignition switch OK?
YES - Go to step 7.
NO - Replace the ignition switch.
7. Remove the starter cut relay from the under-dash fuse/relay box and test it.
Is the relay OK?
YES - Go to step 8.
NO - Replace the starter cut relay.
8. Measure voltage between starter cut relay 4P connector terminal No. 2 and body ground with the ignition switch in the START (III) position.
Is there battery voltage?
YES - Go to step 9.
NO - Check for these problems:
- An open in the wire between starter cut relay 4P connector terminal No. 2 and the ignition switch.
- An open in the wire between the No. 20 (40A) fuse in the under-hood fuse/relay box and the ignition switch.
9. Measure voltage between starter cut relay 4P connector terminal No. 4 and body ground.
Is there battery voltage?
YES - Go to step 10.
NO - Repair an open in the wire between starter cut relay 4P connector terminal No. 4 and the ignition switch.
10. Do the transmission range switch test.
Is the transmission range switch OK ?
YES - Go to step 11.
NO - Replace the transmission range switch.
11. Check for continuity between starter cut relay 4P connector terminal No. 3 and transmission range switch 10P connector terminal No. 1.
Is there continuity?
YES - Go to step 12.
NO - Repair an open in the wire between starter cut relay 4P connector terminal No. 3 and transmission range switch 10P connector terminal No. 1.
12. Remove the starter control relay and test it.
Is the relay OK?
YES - Go to step 13.
NO - Replace the starter control relay.
13. Install the starter cut relay.
14. Measure voltage between starter control relay 5P connector terminal No. 2 and body ground with the ignition switch in the START (III) position.
Is there battery voltage?
YES - Go to step 15.
NO - Repair an open in the wire between starter cut relay 4P connector terminal No. 1 and starter control relay 4P connector terminal No. 2.1
15. Measure voltage between starter control relay 5P connector terminal No. 5 and body ground with the ignition switch in the START (III) position.
Is there battery voltage?
YES - Go to step 16.
NO - Repair an open in the wire between starter cut relay 4P connector terminal No. 1 and starter control relay 5P connector terminal No. 5.
16. Disconnect the PCM connector E (31 P).
17. Check for continuity between starter control relay 5P connector terminal No. 3 and PCM connector terminal E20.
Is there continuity?
YES - Go to step 18.
NO -Repair an open in the wire between starter control relay 5P connector terminal No. 3. and PCM connector terminal E20
18. Check for continuity between starter control relay 5P connector terminal No. 1 and the starter.
Is there continuity?
YES - Update the PCM if it does not have the latest soft ware, or substitute a known-good PCM, then recheck. If the symptom/indication goes away with a known-good PCM, replace the original PCM.
NO - Repair an open in the wire between starter control relay 5P connector terminal No. 1 and the starter.
19. Remove the starter control relay.
20. Check for continuity between starter control relay 5P connector terminal No. 1 and body ground.
Is there continuity?
YES - Repair a short in the wire between starter control relay 5P connector terminal No. 1 and the starter solenoid.
NO - Go to step 21.
21. Check for continuity between starter control relay 5P connector terminal No. 2 and body ground.
Is there continuity?
YES - Repair a short in the wire between starter control relay 5P connector terminal No. 2, terminal No. 4 and starter cut relay 4P connector terminal No. 1.1
NO - Go to step 22.
22. Disconnect the PCM connector E (31 P).
23. Check for continuity between starter control relay 5P connector terminal No. 3 and body ground.
Is there continuity?
YES - Repair a short in the wire between starter control relay 5P connector terminal No. 3 and PCM connector terminal E20
NO - Go to step 24.
24. Check for continuity starter cut relay 4P connector terminal No. 2 and body ground.
Is there continuity7
YES - Repair a short in the wire between starter cut relay 4P connector terminal No. 2 and the ignition switch.
NO - Repair a short in the wire between the No. 20 fuse (40A) in the under-hood fuse/relay box and the ignition switch.
25. Check engine speed during cranking.
Is engine speed above 100 rpm?
YES - Go to step 26.
NO - Remove and disassemble the starter, and check for the following until you find the cause: -
- Excessively worn starter brushes
- Open circuit in commutator brushes
- Dirty or damaged helical splines or drive gear
- Faulty drive gear clutch
26. Check for cranking voltage and current draw.
Is cranking voltage no less than 8.7 V, and current draw no more than 230A?
YES - Remove the starter and inspect its drive gear and the flywheel for damage. Replace any damage parts.
NO - Remove the starter and disassemble the starter, and check for the following until you find the cause:
- Open circuit in starter armature commutator segments
- Starter armature dragging
- Shorted armature winding
- Excessive drag in engine