Inspection Procedure 5

Ignition Circuit:

Connectors: B-03, B-16, B-21, C-49, C-55 <M/T>, C-50, C-54 <A/T>:

Cranks, Won't Start Circuit

CIRCUIT OPERATION
- The ignition coil is energized by Battery positive voltage from the ignition switch through the ignition failure sensor.
- When the ECM or PCM turns off its internal power transistor, battery positive voltage is applied to the ignition power transistor (terminal 3) inside the ignition coil, causing the ignition power transistor to be turned on.
- If the ignition power transistor is turned on, the primary circuit of the ignition coil is energized by grounding the ignition coil through terminal 2, causing the primary current to flow 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.
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. Read 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 liming 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 injector for operation sound.
Using a stethoscope or long blade screwdriver, check the operation sound ("tick-tick-tick") of injectors during cranking.
- An operation sound should be heard.

If a sound is heard, go to Step 6.

If no sound is heard, refer to DTC P0201, P0202, P0203, P0204 - Injector Circuit Malfunction.

STEP 6. Check the circuit at the ignition coil connectors B-16, B-21.
1. Disconnect connectors B-16, B-21 and connect the test harness special tool (MB991348) in between. (All terminals should be connected.)
2. Connect the tachometer to each connector terminal 1.
3. Crank the engine.
- The tachometer should indicate a half cranking speed. If the cranking speed is indicated, go to Step 7.

If the cranking speed is not indicated refer to INSPECTION PROCEDURE 34 - Ignition Circuit System.

STEP 7. Check the ignition timing.
Check the ignition timing at cranking.
Standard value: 5° BTDC ± 3°

If within specifications, go to Step 8.

If not within the 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 8. Check the following items.
Check the following items, and repair or replace the defective items.
a. Check the ignition coils, 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.