DTC B2240: Communication Error With CAN Box: Diagnosis

Required Special Tools: 

• MB991223: Harness Set
• MB992006: Extra Fine Probe
• 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 (Vehicles with CAN communication system)

1. 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. 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.
   4. Turn the ignition switch to the "LOCK" (OFF) position.

   Q: Is the CAN bus line found to be normal? 

   • YES:  Go to Step 2.
   • NO:  Repair the CAN bus line. (Refer to DIAGNOSIS ).
     Fig 1: Connecting Scan Tool To Data Link Connector

     Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
2. STEP 2. Perform "Network/Connect Line Check" of the MMCS service mode. 

   Perform "Network/Connect Line Check" of the MMCS service mode, and check that the communication between the CAN box unit and the multivision display is normal. (Refer to SERVICE MODE  .)

   OK: "CAN BOX OK" is displayed. 

   NOTE: When the communication between the multivision display and the CAN box unit is not possible, "CAN BOX" is not displayed.

   Q: Is "CAN BOX OK" displayed? 

   • YES:  Go to  Step 5.
   • NO:  Go to Step 3.
3. STEP 3. Check CAN box unit connector C-108 and multivision display connector C-12 for loose, corroded or damaged terminals, or terminals pushed back in the connector. 

   Q: Are CAN box unit connector C-108 and multivision display connector C-12 in good condition? 

   • YES:  Go to Step 4.
   • NO:  Repair or replace the damaged component(s). Refer to HARNESS CONNECTOR INSPECTION .
4. STEP 4. Check the wiring harness between CAN box unit connector C-108 (terminal 5, 4, 6) and multivision display connector C-12 (terminal 43, 59, 58). 
   • Check the communication lines for open circuit and short circuit.

   Q: Is the wiring harness between CAN box unit connector C-108 (terminal 5, 4, 6) and multivision display connector C-12 (terminal 43, 59, 58) in good condition? 

   • YES:  Go to Step 5.
   • NO:  The wiring harness may be damaged or the connector(s) may have loose, corroded or damaged terminals, or terminals pushed back in the connector. Repair the wiring harness as necessary.
5. STEP 5. Recheck for diagnostic trouble code. 

   Check again if the DTC is set to the CAN box unit.

   1. Erase the DTC.
   2. Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
   3. Check if DTC is set.
   4. Turn the ignition switch to the "LOCK" (OFF) position.

   Q: Is the DTC set? 

   • YES:  Go to Step 6.
   • NO:  The trouble can be an intermittent malfunction (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTIONS ).
6. STEP 6. Recheck for diagnostic trouble code. 

   Temporarily replace the multivision display, and check if the DTC is set to the CAN box unit.

   1. Erase the DTC.
   2. Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
   3. Check if DTC is set.
   4. Turn the ignition switch to the "LOCK" (OFF) position.

   Q: Is the DTC set? 

   • YES:  Replace the CAN box unit.
   • NO:  Replace the multivision display.