Inspection Procedure 33
Ignition Circuit System
Connectors:
CIRCUIT OPERATION
- The battery positive voltage is applied on the ignition coil by the ignition switch-IG.
- When the ECM
- When the ignition power transistor turns on, the ignition coil's primary circuit is grounded by the ignition power transistor terminal 4. Then the primary current flows to the ignition coil.
TROUBLESHOOTING HINTS (The most likely causes for this case:)
- Malfunction of the ignition coil.
- Malfunction of the ignition power transistor.
- Improper connector contact, open circuit or short-circuited harness wire.
- Malfunction of the ECM
DIAGNOSIS
STEP 1. Check connector B-22 at distributor 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 ignition coil.
Q: Are there any abnormalities?
YES: Go to Step 3.
NO: Repair the ignition coil. Then confirm that the malfunction symptom is eliminated.
STEP 3. Check the ignition power transistor.
Q: Are there any abnormalities?
YES: Go to Step 4.
NO: Repair the ignition power transistor. Then confirm that the malfunction symptom is eliminated.
STEP 4. Check the power supply voltage at distributor connector B-22.
1. Disconnect the connector B-22 and measure at the harness side.
2. Turn the ignition switch to the "ON" position.
3. Measure the voltage between terminal 1 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 5.
NO: Check connector C-06, C-209 and C-301 at intermediate connectors for damage, and repair or replace as required. Refer to Harness Connector Inspection. If intermediate connectors are in good condition, repair harness wire between ignition switch connector C-202 terminal 2 and distributor connector B-22 terminal 1 because of open circuit. Then confirm that the malfunction symptom is eliminated.
STEP 5. Check the continuity at distributor harness side connector B-22.
1. Disconnect the connector B-22 and measure at the harness side.
2. Check for the continuity between terminal 4 and ground.
- Should be less than 2 Ohms.
Q: Is the continuity normal?
YES: Go to Step 6.
NO: Repair harness wire between distributor connector B- 22 terminal 4 and ground because of open circuit or harness damage. Then confirm that the malfunction symptom is eliminated.
STEP 6. Check connector C-111, C-118 at ECM
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 for open circuit between distributor connector B-22 terminal 3 and ECM connector C-111 terminal 11
Q: Is the harness wire in good condition?
YES: Go to Step 8.
NO: Repair it. Then confirm that the malfunction symptom is eliminated.
STEP 8. Check for open circuit between distributor connector B-22 terminal 2 and ECM connector C-118 terminal 45
Q: Is the harness wire in good condition?
YES: Replace the ECM or PCM. Then confirm that the malfunction symptom is eliminated.
NO: Repair it. Then confirm that the malfunction symptom is eliminated.