Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Ignition Control System
WIRING DIAGRAM:
| Step | Check | Yes | No |
|---|---|---|---|
1 CHECK SPARK PLUG CONDITION.
|
Is the spark plug condition status OK? | Go to step 2. | Replace the spark plug. |
2 CHECK IGNITION SYSTEM FOR SPARKS.
|
Does spark occur at each cylinder? | Check fuel pump system. < Ref. to FUEL PUMP CIRCUIT , Diagnostics for Engine Starting Failure. > | Go to step 3. |
3 CHECK POWER SUPPLY CIRCUIT FOR IGNITION COIL AND IGNITOR ASSEMBLY.
|
Is the voltage more than 10 V? | Go to step 4. | Repair the harness and connector.
NOTE:
In this case, repair the following item:
|
4 CHECK HARNESS OF IGNITION COIL AND IGNITOR ASSEMBLY GROUND CIRCUIT.
|
Is the resistance less than 5 Ω? | Go to step 5. | Repair the harness and connector.
NOTE:
In this case, repair the following item:
|
5 CHECK HARNESS BETWEEN ECM AND IGNITION COIL AND IGNITOR ASSEMBLY CONNECTOR.
|
Is the resistance less than 1 Ω? | Go to step 6. | Repair the harness and connector.
NOTE:
In this case, repair the following item:
|
| 6 CHECK HARNESS BETWEEN ECM AND IGNITION COIL AND IGNITOR ASSEMBLY CONNECTOR. Measure the resistance of harness between ECM and engine ground. Connector & terminal: (B137) No. 18 - Engine ground: (B137) No. 19 - Engine ground: (B137) No. 20 - Engine ground: (B137) No. 21 - Engine ground: (B137) No. 22 - Engine ground: (B137) No. 23 - Engine ground: |
Is the resistance more than 1 MΩ? | Go to step 7. | Repair the ground short circuit of harness between ECM and ignition coil and ignitor assembly connector. |
| 7 CHECK POOR CONTACT. Check the poor contact of ECM connector. |
Is there poor contact in ECM connector? | Repair the poor contact of ECM connector. | Check the fuel pump circuit. < Ref. to FUEL PUMP CIRCUIT , Diagnostics for Engine Starting Failure. > |
Use the Manual With the Right Hardware
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
