Code No. P0340: Camshaft Position Sensor System
OPERATION
- Power is supplied to the camshaft position sensor from the battery and is earthed to the engine-ECU connector terminal DGND from the camshaft position sensor.
- A power voltage of 5 V is applied to the camshaft position sensor output terminal from the engine-ECU connector terminal SGC.
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 JUDGEMENT
Check Condition, Judgement Criterion
- Normal signal pattern has not been input for cylinder identification from the crankshaft position sensor signal and camshaft position sensor signal for 2 seconds.
Check Condition
- Engine speed is more than 500 r/min.
- Engine is being cranked.
Judgement Criterion
- Camshaft position sensor output voltage has not changed (no pulse signal is input) for 2 seconds.
FAIL-SAFE AND BACKUP FUNCTION
- Engine runs in learned pattern until engine stops.
- Does not restart the engine after it is stopped once.
- Does not control variable valve timing (V.V.T.).
- Does not operate the MIVEC in high-speed mode.
PROBABLE CAUSES
- Failed camshaft position sensor
- Open/short circuit or harness damage in camshaft position sensor circuit or loose connector contact
- Failed engine-ECU
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STEP 1. Voltage measurement at camshaft position sensor connector (SGC line).
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(1)Disconnect the connector, and measure at the wiring harness side.
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(3)Check the voltage between the camshaft position sensor connector (SGC line) and body earth.
OK: 4.9 - 5.1 V
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Q.
Is the check result normal?
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 Go to Step 4.
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 Go to Step 2.
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STEP 2. Check of short to power supply, short to earth and open circuit in SGC line between camshaft position sensor connector and engine-ECU connector.
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Q.
Is the check result normal?
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Go to Step 3.
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Repair the connector(s) or wiring harness.
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STEP 3. M.U.T.-III diagnosis code
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- Reconfirmation of diagnosis code.
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Q.
Is the diagnosis code set?
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Replace the engine-ECU.
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Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions  ).
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STEP 4. Voltage measurement at camshaft position sensor connector (power supply line).
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(1)Disconnect the connector, and measure at the wiring harness side.
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(3)Check the voltage between the camshaft position sensor connector (power supply line) and body earth.
OK: System voltage
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Q.
Is the check result normal?
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Go to Step 6.
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Go to Step 5.
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STEP 5. Check of short circuit to earth and open circuit in power supply line between camshaft position sensor connector and battery.
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Q.
Is the check result normal?
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Go to Step 3.
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Repair the connector(s) or wiring harness.
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STEP 6. Resistance measurement at camshaft position sensor connector (DGND line).
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(1)Disconnect the connector, and measure at the wiring harness side.
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(2)Check the resistance between the camshaft position sensor connector (DGND line) and body earth.
OK: Continuity (2 Ω or less)
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Q.
Is the check result normal?
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Go to Step 8.
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Go to Step 7.
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STEP 7. Check of open circuit and damage in DGND line between camshaft position sensor connector and engine-ECU connector.
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Q.
Is the check result normal?
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Go to Step 3.
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Repair the connector(s) or wiring harness.
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STEP 8. Perform output wave pattern measurement at camshaft position sensor connector (Using an oscilloscope).
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(1)Use special tool test harness (MB991709) to connect connector, and measure at pick-up harness.
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(4)Check the voltage between the camshaft position sensor connector (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.
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Q.
Is the check result normal?
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Go to Step 3.
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Go to Step 9.
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STEP 9. Check of harness damage in power supply line between camshaft position sensor connector and battery.
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Q.
Is the check result normal?
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Go to Step 10.
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Repair the connector(s) or wiring harness.
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STEP 10. Check of harness damage in SGC line between camshaft position sensor connector and engine-ECU connector.
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Q.
Is the check result normal?
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Go to Step 11.
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Repair the connector(s) or wiring harness.
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STEP 11. Check camshaft sensing cylinder.
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Q.
Is the check result normal?
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Go to Step 12.
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Replace the camshaft sensing cylinder.
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STEP 12. M.U.T.-III diagnosis code
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- Reconfirmation of diagnosis code.
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Q.
Is the diagnosis code set?
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Replace the camshaft position sensor.
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Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).
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