U1101 CAN Communications System Time Out Error A/T Related Data: Diagnosis

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, diagnose the CAN bus line.
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.
1. Connect scan tool MB991958 to the data link connector. (Refer to HOW TO CONNECT THE SCAN TOOL (M.U.T.-III) ).
2. Turn the ignition switch to the "ON" position.
3. Diagnose the CAN bus line. (Refer to HOW TO CONNECT THE SCAN TOOL (M.U.T.-III) ).
4. Turn the ignition switch to the "LOCK" (OFF) position.
5. Disconnect scan tool MB991958.
  Q: Is the CAN bus line found to be normal?
  1. YES: Go to Step 2.
  2. NO: Repair the CAN bus lines. (Refer to CAN BUS DIAGNOSTIC CHART ). Then go to Step 6.
    
    Fig 1: Connecting Special Tool To Data Link Connector
    Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
STEP 2. Using scan tool MB991958, read the diagnostic trouble code.
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.
1. Connect scan tool MB991958 to the data link connector. (Refer to HOW TO CONNECT THE SCAN TOOL (M.U.T.-III) ).
2. Turn the ignition switch to the "ON" position.
3. Check for A/T system diagnostic trouble code. (Refer to HOW TO READ AND ERASE DIAGNOSTIC TROUBLE CODE ).
4. Turn the ignition switch to the "LOCK" (OFF) position.
5. Disconnect scan tool MB991958.
  Q: Is any DTC set?
  1. YES: Repair the automatic transaxle control system. (Refer to DIAGNOSTIC TROUBLE CODE CHART ). Then go to Step 6.
  2. NO: Go to Step 3.
    
    Fig 2: Connecting Special Tool To Data Link Connector
    Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
STEP 3. Using scan tool MB991958, read the diagnostic trouble code.
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.
1. Connect scan tool MB991958 to the data link connector. (Refer to HOW TO CONNECT THE SCAN TOOL (M.U.T.-III) ).
2. Turn the ignition switch to the "ON" position.
3. Check if a DTC, which relates to CAN communication-linked systems below, is set.
  ETACS-ECU
  - DTC U1101: Powertrain control module time-out (related to A/T). (Refer to HOW TO READ AND ERASE DIAGNOSTIC TROUBLE CODE ).
  Combination meter
  - DTC U1101: Powertrain control module time-out (related to A/T). (Refer to HOW TO READ AND ERASE DIAGNOSTIC TROUBLE CODE ).
    
    Fig 3: Connecting Special Tool To Data Link Connector
    Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
  Multi-center display
  - DTC 012: Powertrain control module time-out (related to A/T). (Refer to HOW TO READ AND ERASE DIAGNOSTIC TROUBLE CODE ).
4. Turn the ignition switch to the "LOCK" (OFF) position.
5. Disconnect scan tool MB991958.
  Q: Is DTC 012 or U1101 set?
  1. YES: Go to Step 4.
  2. NO: Go to Step 5.
STEP 4. Using scan tool MB991958, read the diagnostic trouble code.
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.
1. Connect scan tool MB991958 to the data link connector. (Refer to HOW TO CONNECT THE SCAN TOOL (M.U.T.-III) ).
2. Turn the ignition switch to the "ON" position.
3. Use scan tool MB991958 to read the TCL diagnostic trouble codes. (Refer to HOW TO CONNECT THE SCAN TOOL (M.U.T.-III) ).
4. Turn the ignition switch to the "LOCK" (OFF) position.
5. Disconnect scan tool MB991958.
  Q: Is DTC U1101 set?
  1. YES: Replace the PCM. [Refer to POWERTRAIN CONTROL MODULE (PCM) ]. Then go to Step 6.
  2. NO: It can be assumed that this malfunction is intermittent. (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTION ).
    
    Fig 4: Connecting Special Tool To Data Link Connector
    Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
STEP 5. Using scan tool MB991958, read the diagnostic trouble code.
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.
1. Connect scan tool MB991958 to the data link connector. (Refer to HOW TO CONNECT THE SCAN TOOL (M.U.T.-III) ).
2. Turn the ignition switch to the "ON" position.
3. Use scan tool MB991958 to read the TCL diagnostic trouble codes. (Refer to HOW TO CONNECT THE SCAN TOOL (M.U.T.-III) ).
4. Turn the ignition switch to the "LOCK" (OFF) position.
5. Disconnect scan tool MB991958.
  Q: Is DTC U1101 set?
  1. YES: Replace the hydraulic unit (integrated with TCL/ASC-ECU). (Refer to HYDRAULIC UNIT ). Then go to Step 6.
  2. NO: It can be assumed that this malfunction is intermittent. (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTION ).
    
    Fig 5: Connecting Special Tool To Data Link Connector
    Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
STEP 6. Using scan tool MB991958, read the diagnostic trouble code.
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.
1. Connect scan tool MB991958 to the data link connector. (Refer to HOW TO CONNECT THE SCAN TOOL (M.U.T.-III) ).
2. Turn the ignition switch to the "ON" position.
3. Use scan tool MB991958 to read the TCL diagnostic trouble codes. (Refer to HOW TO CONNECT THE SCAN TOOL (M.U.T.-III) ).
4. Turn the ignition switch to the "LOCK" (OFF) position.
5. Disconnect scan tool MB991958.
  Q: Is DTC U1101 set?
  1. YES: Return to Step 1.
  2. NO: The procedure is complete.
    
    Fig 6: Connecting Special Tool To Data Link Connector
    Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.