Code No. P0340: Camshaft Position Sensor System


OPERATION



  • Power is supplied to the camshaft position sensor (terminal No. 3) from the engine-ECU (terminal No. 9) and is earthed to the engine-ECU (terminal No. 30) from the camshaft position sensor (terminal No. 1).
  • A power voltage of 5 V is applied to the camshaft position sensor output terminal (terminal No. 2) from the engine-ECU (terminal No. 14).

FUNCTION



  • The camshaft position sensor detects the position of the camshaft and inputs the pulse signal to the engine-ECU.
  • In response to the camshaft position sensor signal and the crank angle sensor signal, the engine-ECU detects the compression top dead centre of the No. 1 cylinder.
  • Also, in response to the camshaft position sensor signal, the engine-ECU controls variable valve timing (V.V.T.).

TROUBLE JUDGMENT


Check Condition
  • During engine running.
Judgement Criteria
  • A pulse signal from the crank angle sensor continues 264 times and engine speed is less than 440 r/min.
  • A camshaft position sensor signal pattern is not normal.
  • Malfunction is detected twice or more since the ignition switch is turned ON.
Check Condition
  • During engine running.
Judgement Criterion
  • A camshaft position sensor signal pattern is not normal for 2 seconds and engine speed is 440 r/min or more.

FAIL-SAFE AND BACKUP FUNCTION



  • Engine runs in learned pattern until engine stops.
  • Does not control variable valve timing (V.V.T.).

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 6 .
Go to Step 3 .

STEP 3. Connector check: B-26 engine-ECU connector

Q. Is the check result normal?
Go to Step 4 .
Repair or replace the connector.

STEP 4. Check harness between B-06 (terminal No. 2) camshaft position sensor connector and B-26 (terminal No. 14) engine-ECU connector.

  • Check output line for open/short circuit.

Q. Is the check result normal?
Go to Step 5 .
Repair the damaged harness wire.

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

  • Reconfirmation of diagnosis code.

Q. Is 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 6. Perform voltage measurement at B-06 camshaft position sensor connector.

  • Disconnect connector, and measure at harness side.
  • Ignition switch: ON
  • Voltage between terminal No. 3 and earth.
OK: System voltage

Q. Is the check result normal?
Go to Step 9 .
Go to Step 7 .

STEP 7. Connector check: B-26 engine-ECU connector

Q. Is the check result normal?
Go to Step 8 .
Repair or replace the connector.

STEP 8. Check harness between B-06 (terminal No. 3) camshaft position sensor connector and B-26 (terminal No. 9) engine-ECU connector.

  • Check power supply line for open/short circuit.

Q. Is the check result normal?
Go to Step 5 .
Repair the damaged harness wire.

STEP 9. 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 12 .
Go to Step 10 .

STEP 10. Connector check: B-26 engine-ECU connector

Q. Is the check result normal?
Go to Step 11 .
Repair or replace the connector.

STEP 11. Check harness between B-06 (terminal No. 1) camshaft position sensor connector and B-26 (terminal No. 30) engine-ECU connector.

  • Check earthing line for open circuit and damage.

Q. Is the check result normal?
Go to Step 5 .
Repair the damaged harness wire.

STEP 12. Perform output wave pattern measurement at B-06 camshaft position sensor connector (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 value should be 0.6 V or less.There must be no noise in the output wave pattern.

Q. Is the check result normal?
Go to Step 5 .
Go to Step 13 .

STEP 13. Connector check: B-26 engine-ECU connector

Q. Is the check result normal?
Go to Step 14 .
Repair or replace the connector.

STEP 14. Check harness between B-06 (terminal No. 3) camshaft position sensor connector and B-26 (terminal No. 9) engine-ECU connector.

  • Check power supply line for damage.

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

STEP 15. Check harness between B-06 (terminal No. 2) camshaft position sensor connector and B-26 (terminal No. 14) engine-ECU connector.

  • Check output line for damage.

Q. Is the check result normal?
Go to Step 16 .
Repair the damaged harness wire.

STEP 16. Check camshaft sensing portion.

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

STEP 17. M.U.T.-III diagnosis code

  • Reconfirmation of diagnosis code.

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