P0193 – Rail Pressure Sensor Circuit High Input MMC L200 IV



OPERATION

  • A power voltage of 5 V is applied to the rail pressure sensor power terminal (terminal No. 1) from the engine-ECU (terminal No. 70) and earthed to the engine-ECU (terminal No. 88) from the rail pressure sensor (terminal No. 3).
  • The sensor signal is inputted to the engine-ECU (terminal No. 64) from the rail pressure sensor output terminal (terminal No. 2).

  • FUNCTION

  • The rail pressure sensor converts the rail pressure into a voltage signal and inputs the signal to the engine-ECU.
  • In response to the signal, the engine-ECU corrects the fuel injection quantity.

  • TROUBLE JUDGMENT

  • Battery positive voltage is 8 – 16 V
  • 2 seconds later after the ignition switch has been in “ON” position or the engine has started up.
  • The rail pressure sensor output voltage is 4.85 V or more for 0.5 second.

  • PROBABLE CAUSES

  • Failed rail pressure sensor
  • Open circuit in rail pressure sensor circuit or loose connector contact
  • Failed engine-ECU

  • DIAGNOSIS PROCEDURE

    STEP 1. M.U.T.-III data list

  • Item 63: Rail pressure sensor
  • Q. Is the check result normal?

    STEP 2. Connector check: A-44 rail pressure sensor connector

    Q. Is the check result normal?

    STEP 3. Perform resistance measurement at A-44 rail pressure sensor connector.

  • Disconnect connector, and measure at harness side.
  • Resistance between terminal No. 3 and earth.
  • Q. Is the check result normal?

    STEP 4. Connector check: C-105 engine-ECU connector

    Q. Is the check result normal?

    STEP 5. Check harness between A-44 (terminal No. 3) rail pressure sensor connector and C-105 (terminal No. 88) engine-ECU connector.

  • Check earthing line for open circuit.
  • Q. Is the check result normal?

    STEP 6. M.U.T.-III data list

  • Item 63: Rail pressure sensor
  • Q. Is the check result normal?

    STEP 7. M.U.T.-III data list

  • Item 63: Rail pressure sensor
  • Q. Is the check result normal?

    Author: admin