DTC B10C0, B10C1: Interior Temperature Sensor System: Diagnosis

Required Special Tool: 

• 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

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.

   Use scan tool MB991958 to diagnose the CAN bus lines.

   1. Connect scan tool MB991958. Refer to "HOW TO CONNECT THE SCAN TOOL (M.U.T.-III)  ."
   2. Turn the ignition switch to "ON" position.
   3. Diagnose the CAN bus line.

   Q: Is the check result satisfactory? 

   • YES:  Go to Step 2.
   • NO:  Repair the CAN bus lines. Repair the CAN bus lines (Refer to CAN BUS DIAGNOSTIC CHART ).
2. STEP 2. 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? 

   • YES:  It can be assumed that this malfunction is intermittent. Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTIONS .
   • NO:  Go to Step 3.
3. STEP 3. Check interior temperature sensor connector C-08 and A/C controller assembly (A/C-ECU) connector C-146 for loose, corroded or damaged terminals, or terminals pushed back in the connector. 

   Q: Are interior temperature sensor connector C-08 and A/C controller assembly (A/C-ECU) connector C-146 in good condition? 

   • YES:  Go to Step 4.
   • NO:  Repair or replace the connector. Refer to HARNESS CONNECTOR INSPECTION .
4. STEP 4. Check the wiring harness between A/C controller assembly (A/C-ECU) connector C-146 (terminals 13 and 6) and interior temperature sensor connector C-08 (terminals 2 and 1). 
   • Check the sensor signal line and ground line for open and short circuit.

   Q: Is the wiring harness between A/C controller assembly (A/C-ECU) connector C-146 (terminals 13 and 6) and interior temperature sensor connector C-08 (terminals 2 and 1) in good condition? 

   • YES:  Go to Step 5.
   • NO:  Repair the wiring harness.
5. STEP 5. Check the interior temperature sensor. 

   Measure the resistance between connector terminals 1 and 2 under at least two different temperatures. The resistance values should generally match those in the graph.

   NOTE: The temperature at the check should not exceed the range in the graph.

   Q: Is the interior temperature sensor in good condition? 

   • YES:  Replace the A/C controller assembly (A/C-ECU). Then go to Step 6.
   • NO:  Replace the interior temperature sensor. Then go to Step 6.
     Fig 1: Interior Temperature Sensor Resistance Graph

     Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
6. STEP 6. Recheck for diagnostic trouble code. 

   Check again if the DTC is set.

   1. Connect scan tool MB991958 to the data link connector
   2. Turn the ignition switch to the "ON" position.
   3. Check if the DTC is set.
   4. Turn the ignition switch to the "LOCK" (OFF) position.

   Q: Is the check result satisfactory? 

   • YES:  The procedure is complete.
   • NO:  Return to  Step 1.