Code No. P0340: Camshaft Position Sensor System


OPERATION



  • A power voltage of 5 V is applied to the camshaft position sensor power terminal (terminal No. 3) from the engine-ECU (terminal No. 69) and earthed to engine-ECU (terminal No. 90) from the camshaft position sensor (terminal No. 1).
  • The sensor signal is inputted to the engine-ECU (terminal No. 66) from the camshaft position sensor output terminal (terminal No. 2).

FUNCTION



  • The camshaft position sensor detects the top dead centre on the compression stroke of the No. 1 cylinder and inputs a pulse signal to the engine-ECU.

TROUBLE JUDGMENT


Check Conditions
  • While engine is being cranked or is running.
  • Battery positive voltage is 6 - 16 V.
Judgment Criterion
  • The number of output pulses from the camshaft position sensor per engine rotation is 1 or less.

FAIL-SAFE AND BACKUP FUNCTION



  • The rail pressure is controlled in the range between 50 and 100 MPa.
  • The fuel injection amount is restricted (Output restriction).
  • The open angle of the accelerator pedal is restricted.
  • The DPF regeneration is prohibited.
  • The throttle valve is closed (Fixed opening degree).
  • The EGR control is stopped (fully closed).
  • The AS&G control is prohibited.

PROBABLE CAUSES



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

DIAGNOSIS PROCEDURE

STEP 1. Connector check: B-06 camshaft position sensor connector

Q. Is the check result normal?
Go to Step 2 .
Repair or replace the connector.

STEP 2. Perform voltage measurement at B-06 camshaft position sensor connector.

  • Disconnect connector, and measure at harness side.
  • Ignition switch: ON
  • Voltage between terminal No. 2 and earth.
OK: 4.9 - 5.1 V

Q. Is the check result normal?
Go to Step 8 .
Go to Step 3 .

STEP 3. Perform voltage measurement at B-09 engine-ECU connector.

  • Disconnect engine-ECU harness, and connect special tool power plant ECU check harness (MB992291) to measure at connector for inspection.
  • Disconnect B-06 camshaft position sensor connector.
  • Ignition switch: ON
  • Voltage between terminal No. 66 and earth.
OK: 4.9 - 5.1 V

Q. Is the check result normal?
Go to Step 4 .
Go to Step 5 .

STEP 4. Connector check: B-09 engine-ECU connector

Q. Is the check result normal?

    Check and repair harness between B-06 (terminal No. 2) camshaft sensor connector and B-09 (terminal No. 66) engine-ECU connector.

    • Check output line for open circuit.
Repair or replace the connector.

STEP 5. Connector check: B-09 engine-ECU connector

Q. Is the check result normal?
Go to Step 6 .
Repair or replace the connector.

STEP 6. Check harness between B-06 (terminal No. 2) camshaft position sensor connector and B-09 (terminal No. 66) engine-ECU connector

  • Check output line for short circuit.

Q. Is the check result normal?
Go to Step 7 .
Repair the damaged harness wire.

STEP 7. M.U.T.-III diagnosis code

  • Reconfirmation of diagnosis code.

Q. Is the diagnosis code set?
Replace the engine-ECU.
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).

STEP 8. Perform voltage measurement at B-06 camshaft position sensor connector.

  • Use special tool test harness (MB991709) to connect connector, and measure at pick-up harness.
  • Ignition switch: ON
  • Voltage between terminal No. 3 and earth.
OK: 4.9 - 5.1 V

Q. Is the check result normal?
Go to Step 11 .
Go to Step 9 .

STEP 9. Connector check: B-09 engine-ECU connector

Q. Is the check result normal?
Go to Step 10 .
Repair or replace the connector.

STEP 10. Check harness between B-06 (terminal No. 3) camshaft position sensor connector and B-09 (terminal No. 69) engine-ECU connector

  • Check power supply line for open/short circuit and damage.

Q. Is the check result normal?
Go to Step 7 .
Repair the damaged harness wire.

STEP 11. Perform resistance measurement at B-06 camshaft position sensor connector.

  • Disconnect connector, and measure at harness side.
  • Resistance between terminal No. 1 and earth.
OK: Continuity (2 Ω or less)

Q. Is the check result normal?
Go to Step 14 .
Go to Step 12 .

STEP 12. Connector check: B-09 engine-ECU connector

Q. Is the check result normal?
Go to Step 13 .
Repair or replace the connector.

STEP 13. Check harness between B-06 (terminal No. 1) camshaft position sensor connector and B-09 (terminal No. 90) engine-ECU connector

  • Check earthing line for open circuit and damage.

Q. Is the check result normal?
Go to Step 7 .
Repair the damaged harness wire.

STEP 14. Check harness between B-06 (terminal No. 2) camshaft position sensor connector and B-09 (terminal No. 66) engine-ECU connector

  • Check output line for damage.

Q. Is the check result normal?
Go to Step 15 .
Repair the damaged harness wire.

STEP 15. Perform output wave pattern measurement at B-06 camshaft position sensor (Using an oscilloscope).

  • Use special tool test harness (MB991709) to connect connector, and measure at pick-up harness.
  • Engine: Idling
  • Transmission: Neutral
  • Voltage between terminal No. 2 and earth.
OK: Waveforms should be displayed on Inspection procedure using an oscilloscope (Refer to ), its maximum value should be 4.8 V or more, and its minimum valve should be 0.6 V or less with no noise in waveform.

Q. Is the check result normal?
Go to Step 7 .
Go to Step 16 .

STEP 16. Check camshaft position sensor for correct mounting condition.

Q. Is the check result normal?
Go to Step 17 .
Repair.

STEP 17. Check camshaft sensing portion.

Q. Is the check result normal?
Go to Step 18 .
Replace the inlet camshaft.

STEP 18. Replace the camshaft position sensor.

  • After replacing the camshaft position sensor, reconfirm whether the diagnosis code is set.

Q. Is the diagnosis code set?
Replace the engine-ECU.
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).