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 CRUISE CONTROL SYSTEM DIAGNOSTIC TROUBLE CODES .)
- Turn the ignition switch to the "ON" position.
- Check for MFI system DTC (Refer to DIAGNOSTIC FUNCTION .)
Q: Is any DTC set?
- YES: Repair the MFI system (Refer to DIAGNOSTIC TROUBLE CODE TABLE .) Then go to Step 3.
- NO: Go to STEP 2 below.
- 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 CRUISE CONTROL SYSTEM DIAGNOSTIC TROUBLE CODES .)
Q: Is DTC 23 set?
- YES: Replace the ECM [Refer to ENGINE CONTROL MODULE (ECM) ]. Then go to STEP 3 below.
- 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 CRUISE CONTROL SYSTEM DIAGNOSTIC TROUBLE CODES ).
Q: Is DTC 23 set?
- YES: Return to Step 1.
- NO: The procedure is complete.