Inspection Procedure 2: Light intensity cannot be adjusted using sunshade illumination changeover switch: Diagnosis

Required Special Tools: 

• MB991223: Harness Set
• MB992006: Extra Fine Probe

1. STEP 1. Check ETACS-ECU connector C-411, sunshade illumination changeover switch connector E-12 for loose, corroded or damaged terminals, or terminals pushed back in the connector. 

   Q: Is ETACS-ECU connector C-411, sunshade illumination changeover switch connector E-12 in good condition? 

   • YES:  Go to Step 2.
   • NO:  Repair or replace the damaged component(s). Refer to HARNESS CONNECTOR INSPECTION .
2. STEP 2. Check of sunshade illumination changeover switch 

   Check the sunshade illumination changeover switch. Refer to SUNSHADE ILLUMINATION CHANGEOVER SWITCH REMOVAL AND INSTALLATION  .

   Q: Is the check result normal? 

   • YES:  Go to Step 3.
   • NO:  Replace the sunshade illumination changeover switch.
3. STEP 3. Resistance measurement at the E-12 sunshade illumination changeover switch connector 
   1. Disconnect the connector, and measure at the wiring harness side.
   2. Measure the resistance between the E-12 sunshade illumination changeover switch connector terminal No. 1 and the body ground.

      OK: The measured value should be continuity exists (2 ohms or less). 

      Fig 1: Measuring Resistance Between E-12 Sunshade Illumination Changeover Switch Connector Terminal No.1 And Body Ground

      Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

   Q: Is the measured resistance 2 ohms or less? 

   • YES:  Go to  Step 5.
   • NO:  Go to Step 4.
4. STEP 4. Check the wiring harness between the sunshade illumination changeover switch connector E-12 terminal No. 1 and the ground 
   • Check the ground wires for open circuit.

   Q: Is the wiring harness between sunshade illumination changeover switch connector E-12 terminal No. 1 and ground in good condition? 

   • YES:  The trouble can be an intermittent malfunction (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTION ).
   • 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. Check the wiring harness between ETACS-ECU connector C-411 terminal No. 17 and sunshade illumination changeover switch connector E-12 terminal No. 2 
   NOTE: Also check intermediate connector C-226 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If intermediate connector C-226 is damaged, repair or replace the connector as described in HARNESS CONNECTOR INSPECTION .
   • Check the power supply lines for open and short circuit.

   Q: Is the check result normal? 

   • YES:  Go to Step 6.
   • 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.
6. STEP 6. Retest the system 

   While the sunshade illumination is ON, check that the sunshade illumination brightness changes when the sunshade illumination changeover switch is pressed.

   Q: Is the check result normal? 

   • YES:  The trouble can be an intermittent malfunction (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTION ).
   • NO:  Replace the ETACS-ECU.