Code No. P0340: Camshaft Position Sensor System

OPERATION

Power is supplied to the camshaft position sensor connector terminal from the engine-ECU connector terminal 5V and is earthed to the engine-ECU connector terminal DGND from the camshaft position sensor connector terminal.
A power voltage of 5 V is applied to the camshaft position sensor connector signal terminal from the engine-ECU connector terminal SGC.

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 JUDGEMENT

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. Perform voltage measurement at camshaft position sensor connector.

Disconnect connector, and measure at harness side.
Ignition switch: ON
Voltage between terminal engine-ECU SGC line and body earth.

OK: 4.9 - 5.1 V

Q. Is the check result normal?

	Go to Step 4.

	Go to Step 2.

STEP 2. Check of open circuit, and short circuit in SGC line between camshaft position sensor connector and engine-ECU connector.

Q. Is the check result normal?

	Go to Step 3.

	Repair the connector(s) or wiring harness.

STEP 3. M.U.T.-III diagnosis code

Reconfirmation of diagnosis code.

Q. Is diagnosis code stored?

	Replace the engine-ECU.

	Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).

STEP 4. Perform voltage measurement at camshaft position sensor connector.

Disconnect connector, and measure at harness side.
Ignition switch: ON
Voltage between terminal engine-ECU 5V line and body earth.

OK: 4.9 - 5.1 V

Q. Is the check result normal?

	Go to Step 6.

	Go to Step 5.

STEP 5. Check of open circuit, and short circuit in 5V line between camshaft position sensor connector and engine-ECU connector.

Q. Is the check result normal?

	Go to Step 3.

	Repair the connector(s) or wiring harness.

STEP 6. Perform resistance measurement at camshaft position sensor connector.

Disconnect connector, and measure at harness side.
Resistance between terminal engine-ECU DGND line and earth.

OK: Continuity (2 Ω or less)

Q. Is the check result normal?

	Go to Step 8.

	Go to Step 7.

STEP 7. Check of open circuit, and damage in DGND line between camshaft position sensor connector and engine-ECU connector.

Q. Is the check result normal?

	Go to Step 3.

	Repair the connector(s) or wiring harness.

STEP 8. Perform output wave pattern measurement at 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 <M/T>, P range <CVT>
Voltage between terminal engine-ECU SGC line and body 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 3.

	Go to Step 9.

STEP 9. Check of damage in 5V line between camshaft position sensor connector and engine-ECU connector.

Q. Is the check result normal?

	Go to Step 10.

	Repair the connector(s) or wiring harness.

STEP 10. Check of damage in SGC line between camshaft position sensor connector and engine-ECU connector.

Q. Is the check result normal?

	Go to Step 11.

	Repair the connector(s) or wiring harness.

STEP 11. Check camshaft sensing portion.

Q. Is the check result normal?

	Go to Step 12.

	Replace the camshaft.

STEP 12. M.U.T.-III diagnosis code

Reconfirmation of diagnosis code.

Q. Is diagnosis code stored?

	Replace the camshaft position sensor.

	Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).