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. 1) from the engine-ECU (terminal No. 59) and earthed to engine-ECU (terminal No. 78) from the camshaft position sensor (terminal No. 2).
The sensor signal is inputted to the engine-ECU (terminal No. 57) from the camshaft position sensor output terminal (terminal No. 3).

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 one or less.

PROBABLE CAUSES

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

DIAGNOSIS PROCEDURE

STEP 1. Connector check: B-38 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-38 camshaft position sensor connector.

Use special tool test harness (MB991658) 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 8.

	Go to Step 3.

STEP 3. Perform voltage measurement at D-213 engine-ECU connector.

Measure engine-ECU terminal voltage.
Disconnect B-38 camshaft position sensor connector.
Ignition switch: ON
Voltage between terminal No. 57 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: D-213 engine-ECU connector

Q. Is the check result normal?

	Check intermediate connector B-37, and repair if necessary. If intermediate connector is normal, check and repair harness between B-38 (terminal No. 3) camshaft sensor connector and D-213 (terminal No. 57) engine-ECU connector. Check output line for open circuit and damage.

	Repair or replace the connector.

STEP 5. Connector check: D-213 engine-ECU connector

Q. Is the check result normal?

	Go to Step 6.

	Repair or replace the connector.

STEP 6. Check harness between B-38 (terminal No. 3) camshaft position sensor connector and D-213 (terminal No. 57) engine-ECU connector

note

Before checking harness, check intermediate connector B-37, and repair if necessary.

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. When the engine-ECU is replaced, write the chassis number (Refer to GROUP 00 - Precautions Before Service - How to Perform Chassis Number Writing ). After replacing the engine-ECU, register the injector identification code and learn fuel injection (Refer to GROUP 00 - Precautions Before Service - What The Common Rail Engine Learns ).

	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-38 camshaft position sensor connector.

Use special tool test harness (MB991658) to connect connector, and measure at pick-up harness.
Ignition switch: ON
Voltage between terminal No. 1 and earth.

OK: 4.9 - 5.1V

Q. Is the check result normal?

	Go to Step 11.

	Go to Step 9.

STEP 9. Connector check: D-213 engine-ECU connector

Q. Is the check result normal?

	Go to Step 10.

	Repair or replace the connector.

STEP 10. Check harness between B-38 (terminal No. 1) camshaft position sensor connector and D-213 (terminal No. 59) engine-ECU connector

note

Before checking harness, check intermediate connector B-37, and repair if necessary.

Check power supply line for 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-38 camshaft position sensor connector.

Disconnect connector, and measure at harness side.
Resistance between terminal No. 2 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: D-213 engine-ECU connector

Q. Is the check result normal?

	Go to Step 13.

	Repair or replace the connector.

STEP 13. Check harness between B-38 (terminal No. 2) camshaft position sensor connector and D-213 (terminal No. 78) engine-ECU connector

note

Before checking harness, check intermediate connector B-37, and repair if necessary.

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. Perform output wave pattern measurement at B-38 camshaft position sensor (Using an oscilloscope).

Use special tool test harness (MB991658) to connect connector, and measure at pick-up harness.
Engine: Idling
Transmission: Neutral <M/T> or P range <A/T>
Voltage between terminal No. 3 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.

	Replace the camshaft position sensor.