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HOMESERVICE MANUALSMITSUBISHI2012LANCER RALLIARTREPAIR AND DIAGNOSIS (SINGLE PAGE)ACCESSORIES & EQUIPMENTANTI-THEFT SYSTEMSKEYLESS OPERATION SYSTEM (KOS) - LANCERDIAGNOSISSYMPTOM PROCEDURESINSPECTION PROCEDURE 3: ABNORMALITY IN KOS-ECU POWER SUPPLY AND GROUND CIRCUITSTROUBLESHOOTING HINTS
2012 Mitsubishi Lancer Ralliart

Troubleshooting Hints

2012 Mitsubishi Lancer RalliartSECTION Troubleshooting Hints
  • Damaged wiring harness and connectors
  • Malfunction of KOS-ECU
  1. STEP 1. Check KOS-ECU connector C-31 and ETACS-ECU connector C-317 for loose, corroded or damaged terminals, or terminals pushed back in the connector. 

    Q: Is the KOS-ECU connector C-31 and ETACS-ECU connector C-317 in good condition? 

    1. YES:  Go to Step 2.
    2. NO:  Repair the defective connector.
  2. STEP 2. Check the wiring harness between the KOS-ECU connector C-31 (terminal No. 38, 39) and the ETACS-ECU connector C-317 (terminal No. 10, 5) and between the KOS-ECU connector C-31 (terminal No. 14) and the body ground. 
    • Check the power supply line for open and short circuit, and check the ground line for open circuit.
    NOTE: Also check joint connector (1) C-03 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If joint connector (1) C-03 is damaged, repair or replace the damaged component(s) as described in HARNESS CONNECTOR INSPECTION .

    Q: Is the wiring harness between KOS-ECU connector C-31 (terminal No. 38, 39) and the ETACS-ECU connector C-317 (terminal No. 10, 5) and between the KOS-ECU connector C-31 (terminal No. 14) and the body ground in good condition? 

    1. YES:  Go to Step 3.
    2. 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.
  3. STEP 3. Retest the system 

    Q: Does the abnormality in KOS-ECU power supply and ground circuits in good condition? 

    1. YES:  The trouble can be an intermittent malfunction (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTIONS ).
    2. NO:  Replace KOS-ECU and register the ID codes (Refer to ID CODES REGISTRATION PROCEDURES ).
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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.