Code No. P0340: Camshaft Position Sensor System

OPERATION

Power is supplied to the camshaft position sensor (terminal No. 3) from the engine control relay (terminal No. 1) and is earthed to the engine-A/T-ECU (terminal No. 88) 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-A/T-ECU (terminal No. 71).

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-A/T-ECU.

TROUBLE JUDGMENT

Check Conditions

While engine is being cranked or operated.

Judgment Criteria

Camshaft position sensor output voltage has not been changed (no pulse signal is has been input) for 4 seconds.

PROBABLE CAUSE

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

DIAGNOSIS PROCEDURE

STEP 1. Connector check: B-114 camshaft position sensor connector

Q. Is the check result normal?

Go to Step 2 .

Repair or replace.

STEP 2. Perform voltage measurement at B-114 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 4 .

Go to Step 3 .

STEP 3. Connector check: B-15X engine control relay connector

Q. Is the check result normal?

Check power supply line for open/short circuit.

Repair or replace.

STEP 4. Perform voltage measurement at B-114 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 10 .

Go to Step 5 .

STEP 5. Perform voltage measurement at C-112 engine-A/T-ECU connector.

Measure engine-A/T-ECU terminal voltage.
Disconnect B-114 camshaft position sensor connector.
Ignition switch: ON
Voltage between terminal No. 71 and earth.

OK: 4.9 - 5.1 V

Q. Is the check result normal?

Go to Step 6 .

Go to Step 7 .

STEP 6. Connector check: C-112 engine-A/T-ECU connector

Q. Is the check result normal?

Check output line for open circuit.

Repair or replace.

STEP 7. Connector check: C-112 engine-A/T-ECU connector

Q. Is the check result normal?

Go to Step 8 .

Repair or replace.

STEP 8. Check harness between B-114 (terminal No. 2) camshaft position sensor connector and C-112 (terminal No. 71) engine-A/T-ECU connector.

Check output line for short circuit.

Q. Is the check result normal?

Go to Step 9 .

Repair.

STEP 9. M.U.T.-III diagnosis code

Reconfirmation of diagnosis code.

Q. Is the diagnosis code set?

	Replace engine-A/T-ECU.

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

STEP 10. Perform resistance measurement at B-114 camshaft position sensor connector.

Disconnect connector, and measure at harness side.
Resistance between terminal No. 1 and earth.

OK: 2 Ω or less

Q. Is the check result normal?

Go to Step 13 .

Go to Step 11 .

STEP 11. Connector check: C-112 engine-A/T-ECU connector

Q. Is the check result normal?

Go to Step 12 .

Repair or replace.

STEP 12. Check harness between B-114 (terminal No. 1) camshaft position sensor connector and C-112 (terminal No. 88) engine-A/T-ECU connector.

note

Before checking harness, check intermediate connector C-116, and repair if necessary.

Check earthing line for open circuit and damage.

Q. Is the check result normal?

Go to Step 9 .

Repair.

STEP 13. Perform output wave pattern measurement at B-114 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: P range
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 with no noise in waveform.

Q. Is the check result normal?

Go to Step 9 .

Go to Step 14 .

STEP 14. Connector check: B-15X engine control relay connector.

Q. Is the check result normal?

Go to Step 15 .

Repair or replace.

STEP 15. Check harness between B-114 (terminal No. 3) camshaft position sensor connector and B-15X (terminal No. 1) engine control relay connector.

note

Before checking harness, check intermediate connector C-116, and repair if necessary.

Check power supply line for damage.

Q. Is the check result normal?

Go to Step 16 .

Repair.

STEP 16. Connector check: C-112 engine-A/T-ECU connector

Q. Is the check result normal?

Go to Step 17 .

Repair or replace.

STEP 17. Check harness between B-114 (terminal No. 2) camshaft position sensor connector and C-112 (terminal No. 71) engine-A/T-ECU connector.

Check output line for damage.

Q. Is the check result normal?

Go to Step 18 .

Repair.

STEP 18. Check harness between B-114 (terminal No. 1) camshaft position sensor connector and C-112 (terminal No. 88) engine-A/T-ECU connector.

note

Before checking harness, check intermediate connector C-116, and repair if necessary.

Check earthing line for damage.

Q. Is the check result normal?

Go to Step 19 .

Repair.

STEP 19. Check camshaft position sensing cylinder.

Q. Is the check result normal?

	Go to Step 20 .

	Replace camshaft position sensing cylinder.

STEP 20. M.U.T.-III diagnosis code

Reconfirmation of diagnosis code.

Q. Is the diagnosis code set?

	Replace camshaft position sensor.

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