Component Tests and General Diagnostics
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.
- 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 - 400 A
- Voltmeter, 0 - 20 V (accurate within 0.1 V)
- Tachometer, 0 - 1,200 rpm
2. With the shift lever in N or P, 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 22. If it does not 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 the shift lever is in Neutral, 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 the voltage between the 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 the starter B terminal.
5. Check the No. 20 (40 A) fuse in the under-hood fuse/relay box.
Is the fuse OK?
YES - Go to step 6
NO - Go to step 16.
6. Measure the voltage between starter cut relay 4P connector terminal No. 2 and body ground with the ignition switch in START (III).
Is there battery voltage?
YES - Go to step 7.
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 (40 A) fuse in the under-hood fuse/relay box and the ignition switch.
7. Measure the voltage between starter cut relay 4P connector terminal No. 4 and body ground.
Is there battery voltage?
YES - Go to step 8.
NO - Repair an open in the wire between starter cut relay 4P connector terminal No. 4 and the ignition switch.
8. Remove the starter cut relay from the under-dash fuse/relay box.
9. 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 10.
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.
10. Install the starter cut relay.
11. Measure the voltage between starter control relay 5P connector terminal No. 2 and body ground with the ignition switch in START (III).
Is there battery voltage?
YES - Go to step 12.
NO - Repair an open in the wire between starter cut relay 4P connector terminal No. 1 and starter control relay 5P connector terminal No. 2.1
12. Measure the voltage between starter control relay 5P connector terminal No. 5 and body ground with the ignition switch in START (III).
Is there battery voltage?
YES - Go to step 13.
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.
13. Disconnect the PCM connector E (31P).
14. Check for continuity between starter control relay 5P connector terminal No. 3 and PCM connector terminal E20.
Is there continuity?
YES - Go to step 15.
NO - Repair an open in the wire between starter control relay 5P connector terminal No. 3 and PCM connector terminal E20.
15. 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 software, 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.
16. Remove the starter control relay.
17. 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 18.
18. 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.
NO - Go to step 19.
19. Disconnect the PCM connector E (31P).
20. 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 21.
21. Check for continuity starter cut relay 4P connector terminal No. 2 and body ground.
Is there continuity?
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 (40 A) fuse in the under-hood fuse/relay box and the ignition switch.
22. Check the engine speed during cranking.
Is the engine speed above 100 rpm?
YES - Go to step 23.
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
23. Check the cranking voltage and the current draw.
Is the cranking voltage no less than 8.7 V, and is the current draw no more than 230 A?
YES - Remove the starter and inspect its drive gear and the flywheel for damage. Replace any damaged parts.
NO - Remove and disassemble the starter, 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.