Inspection Procedure 11

COMMENT
- In such cases as the above, the air/fuel mixture may be inappropriate when the engine is cold.

TROUBLESHOOTING HINTS
The most likely causes for this case:
- Malfunction of the IAC system.
- Malfunction of the throttle body.
- Malfunction of the injector system.
- Malfunction of the ignition system.

DIAGNOSIS
Required Special Tool:
MB991502: Scan Tool (MUT-II)

STEP 1. Check if the battery terminal is disconnected
Has the battery terminal been disconnected lately?

If no, go to Step 2.

If yes, start the engine and let it run at idle for approximately 10 minutes after engine warm-up. Then, if a malfunction occurs, go to Step 2.

CAUTION: To prevent damage to the scan tool, turn the ignition switch "OFF" before connecting or disconnecting the scan tool.




STEP 2. Using scan tool MB991502, read the diagnostic trouble code (DTC).
If DTC is not output, go to Step 3.

If DTC is output, refer to Diagnostic Trouble Code Chart.

STEP 3. Checking by operating the accelerator pedal
1. Does the engine stall right after the accelerator pedal is released.

If the engine does not stall, go to Step 4.

If the engine stalls easily, carry out the following cleaning or adjustment.
- Clean the throttle valve area .
- Check and adjust the fixed SAS <3.0L Engine>

Then confirm that the malfunction symptom is eliminated.

STEP 4. Check the engine idling.
If the idling state after the engine has been warmed up is correct, go to Step 5.

If the idling stale after the engine has been warmed up is not correct, refer to INSPECTION PROCEDURE 8 - Unstable Idle (Rough Idle, Hunting).




STEP 5. Check the idle air control (IAC) motor operation sound.
1. Check that the engine coolant temperature is 20° C (68° F) or below.

NOTE: Disconnecting the engine coolant temperature sensor connector and connecting the harness side of the connector to another engine coolant temperature sensor that is at 20° C (68° F) or below is also okay.

2. Check the operation sound of the IAC motor can be heard after the ignition is switched "ON" (but without starting the engine).
- An operation sound should be heard.

If a sound is heard, go to Step 6.

If no sound is heard, refer to DTC P0505 - Idle Control System Malfunction <3.0L Engine> or refer to DTC P0505 - Idle Control System Malfunction <3.5L Engine>.

CAUTION: To prevent damage to the scan tool, turn the ignition switch "OFF" before connecting or disconnecting the scan tool.




STEP 6. Using scan tool MB991502, check actuator test items 01, 02, 03, 04, 05, 06: Injector.
If the test items indicate a defect, go to Step 7.

If the test items do not indicate a defect, go to Step 10.




STEP 7. Check the power supply line at injector connectors A-70, A-71, A-72, A-73, A-74, A-75.
1. Disconnect connectors A-70, A-71 A-72, A-73, A-74, A-75 and measure at the harness side.
2. Turn the ignition switch "ON".
3. Measure current while connecting terminal 1 to ground via a 20-ohms resistor.
- Current should be 0.5 ampere or more.

4. Turn the ignition switch "OFF".
If 0.5 ampere or more, go to Step 8.

If less than 0.5 ampere, check intermediate connector A-04, and repair or replace if necessary. Refer to vehicle level Testing and Inspection. If intermediate connector A-04 is in good condition, repair the harness wire between MFI relay connector C-59 and injector connectors A-70, A-71, A-72, A-73, A-74, A-75. Then check that the malfunction is eliminated.




STEP 8. Check the circuits at PCM connector C-89.
1. Disconnect connector C-89 and measure at the harness side.
2. Disconnect PCM connector C-90. Using a jumper wire, connect terminal 49 to ground. Then operate the MFI relay.
3. Turn the ignition switch "ON".
4. Connect terminals 1, 2, 9, 10, 24, 25 to ground via a 20-ohms resistor to measure the current at each injector as follows:

Terminal 1 for the number 1 cylinder injector
Terminal 9 for the number 2 cylinder injector
Terminal 24 for the number 3 cylinder injector
Terminal 2 for the number 4 cylinder injector
Terminal 10 for the number 5 cylinder injector
Terminal 25 for the number 6 cylinder injector

- Current should be 0.3 ampere.

5. Turn the ignition switch "OFF".
If 0.3 ampere or more, go to Step 9.







If less than 0.3 ampere, check intermediate connector A-04. Repair or replace if necessary. Refer to vehicle level Testing and Inspection. If intermediate connector A-04 is in good condition, repair the harness wire between injector connectors A-70, A-71, A-72, A-73, A-74, A-75 and PCM connector C-89. Then check that the malfunction is eliminated.




STEP 9. Check harness connector C-89 at the PCM for damage.
If harness connector C-89 is in good condition, replace the injector.

If harness connector C-89 is damaged, repair or replace it. Refer to vehicle level Testing and Inspection.

Then check that the malfunction is eliminated.

CAUTION: To prevent damage to the scan tool, turn the ignition switch "OFF" before connecting or disconnecting the scan tool.




STEP 10. Using scan tool MB991502, check data list.
1. Check the following items in the data list.
Refer to Data List Reference Table.

a. Item 26: Closed Throttle Position Switch <3.0L Engine>.
b. Item 21: Engine Coolant Temperature Sensor.

If the checks above meet the specifications, go to Step 11.

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

STEP 11. Check the fuel pressure.
Refer to Fuel Pressure Test.

If correct, go to Step 12.

If incorrect, repair or replace. Then confirm that the malfunction symptom is eliminated.

STEP 12. Check the ignition timing.
Refer to On-vehicle Service <3.0L Engine>.

Refer to On-vehicle Service <3.5L Engine>.

If within specifications, go to Step 13.

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

STEP 13. Check the following items.
1. Check the following items, and repair or replace the detective items.

a. Check the ignition coil, spark plugs, spark plug cables.
b. Check compression.
c. Check the engine oil viscosity.

Then confirm that the malfunction symptom is eliminated.