Inspection Procedure 5

Ignition Circuit:

Connectors: B-27, C-51, C-58 <M/T>, C-52, C-55 <A/T>:

CIRCUIT OPERATION
- The battery positive voltage is applied on the ignition coil by the ignition switch-IG.
- When the ECM or PCM turns the power transistor in the ECM or PCM OFF," battery positive voltage is applied on the ignition power transistor (terminals 3), and the ignition power transistor turns on."
- 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.

COMMENT
- In cases such as the above, the cause is probably no spark, fuel delivery, or fuel quality problems.
In addition, foreign materials (water, kerosene, etc.) may be mixed with the fuel.

TROUBLESHOOTING HINTS
The most likely causes for this case:
- Malfunction of the ignition system.
- Malfunction of the fuel pump system.
- Malfunction of the injector system.
- Malfunction of the ECM.
- Malfunction of the PCM.
- Contaminated fuel.
- Malfunction of the immobilizer system.

DIAGNOSIS
Required Special Tools:
MB991502: Scan Tool (MUT-II)
MB991348: Test Harness

STEP 1. Check the Battery positive voltage.
1. Measure the Battery positive voltage during cranking.
- The voltage should be 8 volts or more. If the voltage is 8 volts or more, go to Step 2.

If the voltage is less than 8 volts, check the battery. Refer to Battery - Battery check. Then confirm that the malfunction symptom is eliminated.

CAUTION: To prevent damage to scan tool MB991502, always turn the ignition switch to "LOCK" (OFF) position before connecting or disconnecting scan tool MB991502.

STEP 2. Using scan tool MB991502, read the immobilizer system diagnostic trouble code (DTC).
1. Connect scan tool MB991502 to the data link connector.
2. Turn the ignition switch to "ON" position.
3. Head the immobilizer system DTC.

If immobilizer system DTC is not output, go to Step 3. If immobilizer system DTC is output, refer to Ignition Switch and Immobilizer System - Diagnosis.

STEP 3. Check the timing belt for breaks.
If the timing belt is not broken, go to Step 4.

If the timing belt is broken, replace the timing belt. Then confirm that the malfunction symptom is eliminated.

CAUTION To prevent damage to scan tool MB991502, always turn the ignition switch to "LOCK" (OFF) position before connecting or disconnecting scan tool MB991502.

STEP 4. Using scan tool MB991502, check data list and actuator test.
1. Connect scan tool MB991502 to the data link connector.
2. Check the following items in the data list. Refer to Data List Reference Table.
a. Item 16: Power Supply Voltage.
b. Item 22: Crankshaft Position Sensor.
c. Item 21: Engine Coolant Temperature Sensor.

3. Check the following items in the actuator test. Refer to Actuator Test Reference Table.
a. Item 07: Fuel Pump.

If the checks above meet the specifications, go to Step 5. If the checks above do not meet the specifications, repair or replace. Then confirm that the malfunction symptom is eliminated.

STEP 5. Check the ignition system.
1. Connect the tachometer to inspection connector A-16X terminal 3.
2. Crank the engine.
- The tachometer should indicate cranking speed.

If the cranking speed is normal, go to Step 6. If the cranking speed is not normal, refer to INSPECTION PROCEDURE 33 - Ignition Circuit System.

STEP 6. Check the ignition timing.
1. Check the ignition liming at cranking.

Standard value: 5° BTDC ± 3°

If within specifications, go to Step 7.

If not within specifications, check that the crankshaft position sensor and timing belt cover are in the correct position. Then confirm that the malfunction symptom is eliminated.

STEP 7. Check the left bank injector.
1. Disconnect the left bank injector connector.

2. Measure the resistance between each injector side connector terminals 1 and 2.

Standard value: 13 - 16 ohms (at 20°C (68°F)]

If within specifications, go to Step 8.

If not within specifications, replace the injector.
Then check the malfunction is eliminated.

STEP 8. Check injector intermediate connector B-48 at the right bank injector.
1. Disconnect the injector intermediate harness connector.

2. Measure the resistance between injector side connector terminals 1 and 2 (No.1 injector), 1 and 3 (No.3 injector), 1 and 4 (No.5 injector).

Standard value: 13 - 16 ohms [at 20°C (68-°F)]

If within specifications, go to Step 11.

If not within specifications, go to Step 9.

STEP 9. Check the right bank injector.
1. Remove the intake manifold.
2. Disconnect the injector connector, which deviates from the standard value at Step 8.

3. Measure the resistance between injector side connector terminals 1 and 2.

Standard value: 13 - 16 ohms [at 20°C (68°F)]

If within specifications, go to Step 10.

If not within specifications, replace the injector.
Then check the malfunction is eliminated

STEP 10. Check harness connector B-01 or B-05 or B-26 at the right bank injector for damage.
1. Check the injector connector which deviates from the standard value at Step 8.

If harness connector is in good condition, repair the harness wire between the injector connector and injector intermediate harness connector. Then check the malfunction is eliminated.

If harness connectors is damaged, repair or replace it.
Refer to Harness Connector Inspection.
Then check the malfunction is eliminated.

STEP 11. Check harness connector B-48 at the injector intermediate connector B-48 for damage.
If harness connectors B-48 is in good condition, go to Step
12.

If harness connectors B-48 is damaged, repair or replace it. Refer to Harness Connector Inspection. Then check the malfunction is eliminated.

STEP 12. Check harness connector B-02, B-06, B-25 at the left bank injector for damage.
If harness connectors B-02, B-06, B-25 are in good condition, go to Step 13.
If harness connectors B-02, B-06, B-25 are damaged, repair or replace it.
Refer to Harness Connector Inspection.
Then check the malfunction is eliminated.

STEP 13. Check harness connector C-51 at the ECM or harness connector C-52 at the PCM for damaged.
If harness connectors C-51 or C-52 are in good condition, go to Step 14.
If harness connectors C-51 or C-52 are damaged, repair or replace it.
Refer to Harness Connector Inspection.
Then check the malfunction is eliminated.

STEP 14. Check the harness wire between injector connectors B-01, B-02, B-05, B-06, B-25, B-26 and ECM connector C-51 or PCM connector C-52 .
If the wire between injector connectors B-01, B-02, B-05, B-06, B-25, B-26 and ECM connector C-51 or PCM connector C-52 are not damaged, go to Step 15.
If the wire between injector connectors B-01, B-02, B-05, B-06, B-25, B-26 and ECM connector C-51 or PCM connector C-52 are damaged, repair it.
Then check the malfunction is eliminated.

STEP 15. Check the following Items.
1. Check the following items, and repair or replace the defective items.
a. Check the ignition coil, spark plugs, spark plug cables.
b. Check if the injectors are clogged.
c. Check if fuel is contaminated.
d. Check compression.

Then confirm that the malfunction symptom is eliminated.