Engine Control System: Diagnosis Mitsubishi Galant IX

TROUBLESHOOTING STRATEGY

Use these steps to plan your diagnostic strategy.

If you follow them carefully, you will be sure that you have exhausted most of the possible ways to find an engine control system fault.

1. Gather information from the customer.
2. Verify that the condition described by the customer exists.
3. Find the malfunction by following the Symptom Chart.
4. Verify that the malfunction is eliminated.

Scheme 40

TROUBLESHOOTING HINTS (The most likely causes for this case:)

1. Malfunction of the throttle body.
2. Malfunction of the accelerator pedal position sensor (APS).
3. Malfunction of the PCM.

DIAGNOSIS

Required Special Tool

1. MB991958: Scan Tool (MUT-III sub assembly) MB991824: V.C.I. MB991827: USB Cable MB991910: Main Harness A

Scheme 41

1. STEP 1. Using scan tool MB991958, read the diagnostic trouble code (DTC). 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. Ensure that the ignition switch is at the "LOCK" (OFF) position. Start up the personal computer. Connect special tool MB991827 to special tool MB991824 and the personal computer. Connect special tool MB991910 to special tool MB991824. Connect special tool MB991910 to the data link connector. Turn the power switch of special tool MB991824 to the "ON" position. NOTE: When special tool MB991824 is energized, special tool MB991824 indicator light will be illuminated in a green color. Start the MUT-III system on the personal computer. Turn the ignition switch to the "ON" position. Check for MFI system diagnostic trouble code. Refer to MFI DIAGNOSIS «MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS - 2.4L»(ref-205454-S38576536922005111900000) or «MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS - 3.8L»(ref-205455-S37700610732005111900000) . Turn the ignition switch to the "LOCK" (OFF) position, and then remove scan tool MB991958 in the reverse order of installation. Q: Is any DTC set? YES: Refer to DIAGNOSTIC TROUBLE CODE CHART «MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS - 2.4L»(ref-205454-S38576536922005111900000) or «MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS - 3.8L»(ref-205455-S37700610732005111900000) . NO: Go to Step 2.
2. STEP 2. Retest the system. Q: Does the throttle valve fully open and close? YES: The procedure is complete. NO: Return to Step 1.

1. Malfunction of the accelerator pedal.
2. Incorrectly installed accelerator pedal
3. Malfunction of the accelerator pedal position sensor (APS).

Required Special Tool

1. MB991958: Scan Tool (MUT-III sub assembly) MB991824: V.C.I. MB991827: USB Cable MB991910: Main Harness A

Scheme 42

1. STEP 1. Check if the accelerator pedal and the accelerator pedal are installed correctly. Q: Are the accelerator pedal and the accelerator pedal installed correctly? YES: Go to Step 2. NO: Replace and reinstall the accelerator pedal. Refer to «ACCELERATOR CABLE AND PEDAL»(ref-205462-S23187258142005111900000) . Go to Step 3 .
2. STEP 2. Using scan tool MB991958, read the diagnostic trouble code (DTC). 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. Ensure that the ignition switch is at the "LOCK" (OFF) position. Start up the personal computer. Connect special tool MB991827 to special tool MB991824 and the personal computer. Connect special tool MB991910 to special tool MB991824. Connect special tool MB991910 to the data link connector. Turn the power switch of special tool MB991824 to the "ON" position. NOTE: When special tool MB991824 is energized, special tool MB991824 indicator light will be illuminated in a green color. Start the MUT-III system on the personal computer. Turn the ignition switch to the "ON" position. Check for MFI system diagnostic trouble code. Refer to MFI DIAGNOSIS «MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS - 2.4L»(ref-205454-S38576536922005111900000) or «MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS - 3.8L»(ref-205455-S37700610732005111900000) . Turn the ignition switch to the "LOCK" (OFF) position, and then remove scan tool MB991958 in the reverse order of installation. Q: Is any DTC set? YES: Refer to DIAGNOSTIC TROUBLE CODE CHART «MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS - 2.4L»(ref-205454-S38576536922005111900000) or «MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS - 3.8L»(ref-205455-S37700610732005111900000) . NO: Go to Step 3.
3. STEP 3. Retest the system. Q: Does the accelerator pedal work normally? YES: The procedure is complete. NO: Return to Step 1.

Scheme 43