DTC 020: Failures Information on Powertrain Control Module (Related to Engine): Diagnosis

Required Special Tools:

MB991958: Scan Tool (MUT-III Sub Assembly)
- MB991824: Vehicle Communication Interface (V.C.I.)
- MB991827: MUT-III USB Cable
- MB991910: MUT-III Main Harness A (Vehicles with CAN communication system)

STEP 1. Using scan tool MB991958, diagnose the CAN bus line.
Use scan tool MB991958 to diagnose the CAN bus lines.
1. Connect scan tool MB991958 to the data link connector.
  
  Fig 1: Connecting Scan Tool MB991958 To Data Link Connector
  Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
2. Turn the ignition switch to "ON" position.
3. Diagnose the CAN bus line.
Q: Is the check result satisfactory?
1. YES : Go to Step 2.
2. NO : Repair the CAN bus lines (Refer to DIAGNOSIS < Vehicles without advanced air bag > or < Vehicles with advanced air bag >). On completion, go to Step 6.
STEP 2. Using scan tool MB991958, read the MFI system diagnostic trouble code.
Check if an MFI system DTC is set.

Q: Is the DTC set?
1. YES : Diagnose the MFI system by referring to MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS .
2. NO : Go to Step 3.
STEP 3. Using scan tool MB991958, read the other system diagnostic trouble code.
Check if a DTC, which relates to CAN communication-linked systems below, is set.

ABS-ECU
- DTC U1120: Failure information on powertrain control module (related to engine) < vehicles with TCL >
Combination meter
- DTC 020: Failure information on powertrain control module (related to engine)
A/C-ECU
- DTC U1120: Failure information on powertrain control module (related to engine)
Q: Is any of these DTCs set?
1. YES : Go to Step 4.
2. NO : Go to Step 5.
STEP 4. Recheck for diagnostic trouble code.
Recheck if the DTC is set.
1. Erase the DTC.
2. Turn the ignition switch to "ON" position.
3. Check if the DTC is set.
Q: Is the check result satisfactory?
1. YES : A poor connection, open circuit or other intermittent malfunction is present in the lines between the powertrain control module and the multi-center display unit (middle grade type) (Refer to HOW TO USE TROUBLESHOOTING/INSPECTION SERVICE POINTS - HOW TO COPE WITH INTERMITTENT MALFUNCTION ).
2. NO : Replace powertrain control module and then go to Step 6.
STEP 5. Recheck for diagnostic trouble code.
Recheck if the DTC is set.
1. Erase the DTC.
2. Turn the ignition switch to "ON" position.
3. Check if the DTC is set.
Q: Is the check result satisfactory?
1. YES : A poor connection, open circuit or other intermittent malfunction is present in the lines between the powertrain control module and the middle grade type multi-center display unit (Refer to HOW TO USE TROUBLESHOOTING/INSPECTION SERVICE POINTS - HOW TO COPE WITH INTERMITTENT MALFUNCTION ).
2. NO : Replace multi-center display unit (middle grade type) and then go to step 6.
STEP 6. Recheck for diagnostic trouble code.
Recheck if the DTC is set.
1. Erase the DTC.
2. Turn the ignition switch to "ON" position.
3. Check if the DTC is set.
Q: Is the check result satisfactory?
1. YES : The procedure is complete.
2. NO : Go to Step 1.