Inspection Procedure 5
Cranks, Won't StartCranks, Won't Start Circuit
- Refer to, Ignition circuit system.
CIRCUIT OPERATION
- Refer to, Ignition circuit system.
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
- Contaminated fuel.
DIAGNOSIS
Required Special Tools:
- MB991958: Scan Tool (MUT-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: USB Cable
- MB991911: Main Harness B
STEP 1. Check the Battery positive voltage.
1. Measure the Battery positive voltage during cranking.
- A tachometer move.
Q: Does a tachometer move?
YES: Go to Step 2.
NO: Check the battery. Refer to Battery - Battery check. Then confirm that the malfunction symptom is eliminated.
STEP 2. Check the timing belt for breaks.
Q: Is the timing belt good condition?
YES: Go to Step 3.
NO: Replace timing belt. Then confirm that the malfunction symptom is eliminated.
STEP 3 Using scan tool MB991958, check data list.
CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.
1. Connect scan tool or MB991958 to the data link connector.
2. Turn the ignition switch to the "ON" position.
3. Check the following items in the data List. Refer to Data List Reference Table. Data List Reference Table & Normal Scan Data Values
a. Item 16: Power Supply Voltage.
b. Item 22: Crankshaft Position Sensor.
c. Item 21: Engine Coolant Temperature Sensor.
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Are they operating properly?
YES: Go to Step 4.
NO: Repair or replace.Then confirm that the malfunction symptom is eliminated.
STEP 4. Using scan tool MB991958, check actuator test.
1. Turn the ignition switch to the "ON" position.
2. Check the following items in the actuator test. Refer to Actuator Test Reference Table. Actuator List Reference Table
a. Item 07: Fuel pump.
3. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the actuator operating properly?
YES: Go to Step 5.
NO: Repair or replace. Then confirm that the malfunction symptom is eliminated.
STEP 5. Check the ignition system.
1. Connect the tachometer to engine speed detection connector A-12X (terminal No. 1).
2. Crank the engine.
- A tachometer moves.
3. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Does a tachometer move?
YES: Go to Step 6.
NO: Refer to INSPECTION PROCEDURE 33 - Ignition Circuit System.
STEP 6. Check the ignition timing.
1. Check the ignition timing at cranking.
Standard value: 5 ° BTDC ± 3 °
Q: Is the ignition timing normal?
YES: Go to Step 7.
NO: 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 B-02, B-06, B-25.
2. Measure the resistance between each injector side connector terminal No. 1 and No. 2.
Standard value: 13 - 16 Ohms [at 20 °C (68 °F)]
Q: Is the measured resistance between 13 and 16 Ohms?
YES: Go to Step 8.
NO: Replace the faulty injector. Then confirm that the malfunction symptom is eliminated.
STEP 8. Check the right bank injector resistance at injector intermediate connector B-48.
1. Disconnect the injector intermediate connector B-48.
2. Measure the resistance between each male connector side terminal.
a. Measure the resistance between terminal 1 and 2 when measuring No. 1 cylinder injector.
b. Measure the resistance between terminal 1 and 3 when measuring No. 3 cylinder injector.
c. Measure the resistance between terminal 1 and 4 when measuring No. 5 cylinder injector.
- Resistance should be between 13 and 16 Ohms [at 20 °C (68 °F)].
Q: Is the measured resistance between 13 and 16 Ohms?
YES: Go to Step 11.
NO: Go to Step 9.
STEP 9. Check the right bank injector.
1. Remove the intake manifold.
2. Disconnect the right bank injector connector, which deviates from the standard value at Step 8.
3. Measure the resistance between injector side connector terminal No. 1 and No. 2.
Standard value: 13 - 16 Ohms [at 20 °C (68 °F)]
Q: Is the measured resistance between 13 and 16 Ohms ?
YES: Go to Step 10.
NO: Replace the injector. Then confirm that the malfunction symptom is eliminated.
STEP 10. Check connector B-01 or B-05 or B-26 at right bank injector for damage.
1. Check the injector connector, which deviates from the standard value at Step 8.
Q: Is the connector in good condition?
YES: Repair harness wire between injector intermediate connector and right bank injector connector because of harness damage. Then confirm that the malfunction symptom is eliminated.
NO: Repair or replace it. Refer to Harness Connector Inspection. Then confirm that the malfunction symptom is eliminated.
STEP 11. Check connector B-48 at injector intermediate connector for damage.
Q: Is the connector in good condition?
YES: Go to Step 12.
NO: Repair or replace it. Refer to Harness Connector Inspection. Then confirm that the malfunction symptom is eliminated.
STEP 12. Check connector B-02, B-06, B-25 at left bank injector for damage.
Q: Is the connector in good condition?
YES: Go to Step 13.
NO: Repair or replace it. Refer to Harness Connector Inspection. Then confirm that the malfunction symptom is eliminated.
STEP 13. Check connector C-51 at ECM
Q: Is the connector in good condition?
YES: Go to Step 14.
NO: Repair or replace it. Refer to Harness Connector Inspection. Then confirm that the malfunction symptom is eliminated.
STEP 14. Check for harness damage between injector connector and ECM connector
a. Check the harness wire between injector connector B-01 (terminal No. 2) and ECM connector C-51 (terminal No. 1)
b. Check the harness wire between injector connector B-02 (terminal No. 2) and ECM connector C-51 (terminal No. 9)
c. Check the harness wire between injector connector B-05 (terminal No. 2) and ECM connector C-51 (terminal No. 24)
d. Check the harness wire between injector connector B-06 (terminal No. 2) and ECM connector C-51 (terminal No. 2)
e. Check the harness wire between injector connector B-26 (terminal No. 2) and ECM connector C-51 (terminal No. 10)
f. Check the harness wire between injector connector B-25 (terminal No. 2) and ECM connector C-51 (terminal No. 25)
Q: Is the harness wire in good condition?
YES: 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.
NO: Repair it. Then confirm that the malfunction symptom is eliminated.