DTC U0151: SRS-ECU CAN timeout: Diagnosis

Required Special Tools: 

• MB991958: Scan Tool (M.U.T.-III Sub Assembly)
  • MB991824: Vehicles 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? 

      1. YES:  Go to Step 2.
      2. NO:  Repair the CAN bus line (Refer to DIAGNOSIS ).
         Fig 1: Connecting Special Tool MB991910 To Data Link Connector

         Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
2. STEP 2. Using scan tool MB991958, read the SRS-ECU diagnostic trouble code 

   Check again if the DTC is set to the SRS-ECU.

   Q: Is the DTC set? 

   1. YES:  Troubleshoot the SRS (Refer to TROUBLESHOOTING ).
   2. NO:  Go to Step 3.
3. STEP 3. Using scan tool MB991958, read the A/C-ECU diagnostic trouble code. 

   Check if the DTC U0151 is set to the A/C-ECU.

   Q: Is the DTC set? 

   1. YES:  Go to Step 4.
   2. NO:  Go to Step  5.
4. STEP 4. Recheck for diagnostic trouble code. 

   Check again if the DTC is set to the combination meter.

   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? 

      1. YES:  Replace the SRS-ECU.
      2. NO:  The trouble can be an intermittent malfunction such as a poor connection or open circuit in the CAN bus lines between the SRS-ECU and the combination meter (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTION ).
5. STEP 5. Recheck for diagnostic trouble code. 

   Check again if the DTC is set to the combination meter.

   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? 

      1. YES:  Replace the combination meter.
      2. NO:  The trouble can be an intermittent malfunction such as a poor connection or open circuit in the CAN bus lines between the SRS-ECU and the combination meter (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTION ).