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.
- Gather information from the customer.
- Verify that the condition described by the customer exists.
- Find the malfunction by following the Symptom Chart.
- Verify that the malfunction is eliminated.
SYMPTOM CHART
| Symptom | Inspection procedure |
|---|---|
| Throttle valve will not fully open or close | Refer to INSPECTION PROCEDURE 1: THROTTLE VALVE WILL NOT FULLY OPEN OR CLOSE |
| Accelerator pedal operation not smooth (over acceleration) | Refer to INSPECTION PROCEDURE 2: ACCELERATOR PEDAL OPERATION NOT SMOOTH (OVER ACCELERATION) |
SYMPTOM CHART
TROUBLESHOOTING HINTS (THE MOST LIKELY CAUSES FOR THIS CASE:)
- Malfunction of the throttle body.
- Malfunction of the APS.
- Malfunction of the engine control module (ECM.)
DIAGNOSIS
Required Special Tools
- MB991958: Scan Tool (M.U.T.-III Sub Assembly) MB991824: Vehicle Communication Interface (V.C.I.) MB991827: M.U.T.-III USB Cable MB991910: M.U.T.-III Main Harness A
Scheme 6
- STEP 1. Using scan tool MB991958, check the MFI system 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 M.U.T.-III system on the personal computer. Turn the ignition switch to the "ON" position. Check for MFI system DTC (Refer to «DIAGNOSTIC FUNCTION»(ref-592554-S08381383192014011000000) ) < 2.0L ENGINE Non-turbo >, (Refer to «DIAGNOSTIC FUNCTION»(ref-592555-S09507504502014011000000) ) < 2.0L ENGINE Turbo > or (Refer to «DIAGNOSTIC FUNCTION»(ref-592556-S33445160532014011000000) ) < 2.4L ENGINE >. 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: Diagnose the MFI system (Refer to «DIAGNOSTIC TROUBLE CODE CHART»(ref-592554-S34172480472014011000000) ) < 2.0L ENGINE Non-turbo >, (Refer to «DIAGNOSTIC TROUBLE CODE CHART»(ref-592555-S21340300262014011000000) ) < 2.0L ENGINE Turbo > or (Refer to «DIAGNOSTIC TROUBLE CODE CHART»(ref-592556-S26682004632014011000000) ) < 2.4L ENGINE >. Then go to Step 3 . NO: Go to Step 2.
- STEP 2. Retest the system. Q: Does the throttle valve work with the accelerator pedal operation? YES: It can be assumed that this malfunction is intermittent (Refer to «HOW TO COPE WITH INTERMITTENT MALFUNCTIONS»(ref-592551-S36408212772014011000000) ). NO: Return to Step 1 .
- STEP 3. Retest the system. Q: Does the throttle valve work with the accelerator pedal operation? YES: The procedure is complete. NO: Return to Step 1 .
- Malfunction of the accelerator pedal.
- Incorrectly installed accelerator pedal.
- Malfunction of the APS.
Required Special Tools
- MB991958: Scan Tool (M.U.T.-III Sub Assembly) MB991824: V.C.I. MB991827: M.U.T.-III USB Cable MB991910: M.U.T.-III Main Harness A
- STEP 1. Check if the accelerator pedal is installed correctly. Q: Is the accelerator pedal installed correctly? YES: Go to Step 2. NO: Remove and reinstall the accelerator pedal (Refer to «ACCELERATOR PEDAL»(ref-592789-S35925930832014011000000) ). Then go to Step 4 .
- STEP 2. Using scan tool MB991958, check the MFI system 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 M.U.T.-III system on the personal computer. Turn the ignition switch to the "ON" position. Check for MFI system DTC (Refer to «DIAGNOSTIC FUNCTION»(ref-592554-S08381383192014011000000) ) < 2.0L ENGINE Non-turbo >, (Refer to «DIAGNOSTIC FUNCTION»(ref-592555-S09507504502014011000000) ) < 2.0L ENGINE Turbo > or (Refer to «DIAGNOSTIC FUNCTION»(ref-592556-S33445160532014011000000) ) < 2.4L ENGINE >. 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: Diagnose the MFI system (Refer to «DIAGNOSTIC TROUBLE CODE CHART»(ref-592554-S34172480472014011000000) ) < 2.0L ENGINE Non-turbo >, (Refer to «DIAGNOSTIC TROUBLE CODE CHART»(ref-592555-S21340300262014011000000) ) < 2.0L ENGINE Turbo > or (Refer to «DIAGNOSTIC TROUBLE CODE CHART»(ref-592556-S26682004632014011000000) ) < 2.4L ENGINE >. Then go to Step 4 . NO: Go to Step 3.
- STEP 3. Retest the system. Q: Does the accelerator pedal work normally? YES: It can be assumed that this malfunction is intermittent (Refer to «HOW TO COPE WITH INTERMITTENT MALFUNCTIONS»(ref-592551-S36408212772014011000000) ). NO: Return to Step 1 .
- STEP 4. Retest the system. Q: Does the accelerator pedal work normally? YES: The procedure is complete. NO: Return to Step 1 .