P0502 – Vehicle Speed Sensor Low Input 2WD-M-T and 4WD vehicles MMC L200 IV


  • A power voltage of 5 V is applied to the vehicle speed sensor (terminal No. 3) from the engine-ECU (terminal No. 114).


  • The vehicle speed sensor converts the vehicle speed to the voltage, and then input it into the engine-ECU


  • Engine is running
  • Engine coolant temperature is 80°C or higher
  • The last fuel injection rate exceeds the specified value.
  • Engine speed is 2,900 r/min or more.
  • Vehicle speed is 5 km/h or lower for 2 seconds.


  • Failed vehicle speed sensor
  • Open/short circuit or harness damage in vehicle speed sensor circuit or loose connector contact
  • Failed engine-ECU


    STEP 1. Check the speed meter

    Q. Is the check result normal?

    STEP 2. M.U.T.-III data list

  • Item 4: Vehicle speed sensor
  • Q. Is the check result normal?

    STEP 3. Connector check: C-103 engine-ECU connector

    Q. Is the check result normal?

    STEP 4. Check harness between C-103 (terminal No. 114) engine-ECU connector and B-01 (terminal No. 3) Vehicle speed sensor connector.

  • Check output line for open circuit and damage.
  • Q. Is the check result normal?

    STEP 5. M.U.T.-III diagnosis code

  • Reconfirmation of diagnosis code.
  • Q. Is the diagnosis code set?

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