Inspection Procedure 31
Ignition Switch-ST System.
Connectors:
CIRCUIT OPERATION
- The battery positive voltage is supplied to the ECM (terminal 68) via the starter relay during engine cranking. With this, the ECM detects that the engine is being cranked.
TROUBLESHOOTING HINTS (The most likely causes for this case:)
- Malfunction of the ignition switch.
- Malfunction of the starter relay.
- Improper connector contact, open circuit or short-circuited harness wire.
- Malfunction of the ECM.
DIAGNOSIS
STEP 1. Check connector A-18X at starter relay for damage.
Q: Is the connector in good condition?
YES: Go to Step 2.
NO: Repair or replace it. Refer to Harness Connector Inspection. Then confirm that the malfunction symptom is eliminated.
STEP 2. Check the starter relay.
Q: Are there any abnormalities?
YES: Go to Step3.
NO: Repair or replace it. Then confirm that the malfunction symptom is eliminated.
STEP 3. Check the power supply voltage at starter relay connector A-18X.
1. Disconnect the connector A-18X and measure at the harness side.
2. Turn the ignition switch to the "START" position.
3. Measure the voltage between terminal 3, 4 and ground. Voltage should be battery positive voltage.
4. Turn the ignition switch to the "LOCK"(OFF) position.
Q: Is the voltage normal?
YES: Go to Step 4.
NO: Repair harness wire between ignition switch connector C-202 terminal 5 and starter relay connector A-18X terminal 3, 4 because of open circuit. Then confirm that the malfunction symptom is eliminated.
STEP 4. Check connector C-118 at ECM for damage.
Q: Is the connector in good condition?
YES: Go to Step 5.
NO: Repair or replace it. Refer to Harness Connector Inspection. Then confirm that the malfunction symptom is eliminated.
STEP 5. Check the power supply voltage at ECM connector C-118.
1. Disconnect the connector C-118 and measure at the harness side
2. Turn the ignition switch to the "START" position.
3. Measure the voltage between terminal 68 and ground.
- Voltage should be battery positive voltage.
4. Turn the ignition switch to the "LOCK"(OFF) position.
Q: Is the voltage normal?
YES: Go to Step 6.
NO: Repair harness wire between starter relay connector A-18X terminal 2 and ECM connector C-118 terminal 68 because of open circuit. Then confirm that the malfunction symptom is eliminated.
STEP 6. Check connector C-02 at interlock switch for damage.
Q: Is the connector in good condition?
YES: Go to Step 7.
NO: Repair or replace it. Refer to Harness Connector Inspection. Then confirm that the malfunction symptom is eliminated.
STEP 7. Check the interlock switch.
Q: Are there any abnormalities?
YES: Go to Step 8.
NO: Repair or replace it. Then confirm that the malfunction symptom is eliminated.
STEP 8. Check the power supply voltage at interlock switch connector C-02.
1. Disconnect the connector C-02 and measure at the harness side.
2. Turn the ignition switch to the "START" position.
3. Measure the voltage between terminal 2 and ground. Voltage should be battery positive voltage.
4. Turn the ignition switch to the "LOCK"(OFF) position.
Q: Is the voltage normal?
YES: Go to Step 9.
NO: Check connector C-06 at intermediate connector for damage, and repair or replace as required. Refer to Harness Connector Inspection. If intermediate connectors is in good condition, repair harness wire between starter relay connector A-18X terminal 1 and interlock switch connector C-02 terminal 2 because of open circuit. Then confirm that the malfunction symptom is eliminated.
STEP 9. Check the continuity at interlock switch harness side connector C-02.
1. Disconnect the connector C-02 and measure at the harness side.
2. Check for the continuity between terminal 1 and ground. Should be less than 2 Ohms.
Q: Is the continuity normal?
YES: Replace the ECM. Then confirm that the malfunction symptom is eliminated.
NO: Repair harness wire between interlock switch connector C-02 terminal 1 and ground because of open circuit or harness damage. Then confirm that the malfunction symptom is eliminated.