Diagnostic Procedure
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. Using scan tool MB991958, check for 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.
- Connect scan tool MB991958 to the data link connector (Refer to HOW TO CONNECT THE SCAN TOOL (M.U.T.-III) ).
- Turn the ignition switch to the "ON" position.
- Check for MFI system DTC (Refer to
MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS
).
Q: Is any DTC set?
- YES: Repair the MFI system (Refer to DIAGNOSTIC TROUBLE CODE CHART ). Then go to Step 3.
- NO: Go to Step 2.
- STEP 2. Read the cruise control system DTC.
- Disconnect the negative (-) battery terminal, to erase the DTC of the cruise control system.
- Connect the negative (-) battery terminal.
- Turn the ignition switch to the "ON" position, and press the "ON/OFF" switch to turn the cruise control system to ON (turn on the "CRUISE" indicator light).
- After turning the cruise control system to ON, when 2 minutes or more has elapsed without operating the cruise control switches, read the DTC of the cruise control system (Refer to HOW TO CONNECT THE SCAN TOOL (M.U.T.-III) ).
Q: Is DTC 23 set?
- YES: Replace the ECM (Refer to ENGINE CONTROL MODULE (ECM) ). Then go to Step 3.
- NO: It can be assumed that this malfunction is intermittent (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTION ).
- STEP 3. Read the cruise control system DTC.
- Disconnect the negative (-) battery terminal, to erase the DTC of the cruise control system.
- Connect the negative (-) battery terminal.
- Turn the ignition switch to the "ON" position, and press the "ON/OFF" switch to turn the cruise control system to ON (turn on the "CRUISE" indicator light).
- After turning the cruise control system to ON, when 2 minutes or more has elapsed without operating the cruise control switches, read the DTC of the cruise control system (Refer to HOW TO CONNECT THE SCAN TOOL (M.U.T.-III) ).
Q: Is DTC 23 set?
- YES: Return to Step 1.
- NO: The procedure is complete.