P0340
Camshaft Position Sensor Circuit:
Connectors:
CIRCUIT OPERATION
- The camshaft position sensor power is supplied from the MFI relay (terminal No.4).
- Terminal No.7 of the camshaft position sensor is grounded with ECM (terminal No.34)
- A 5-volt voltage is applied on the camshaft position sensor output terminal (terminal No.5) from the ECM (terminal No.50)
TECHNICAL DESCRIPTION
- The camshaft position sensor functions to detect the top dead center position of the number 1 cylinder and to convert that data to pulse signals that are input to the ECM
- When the engine is running, the camshaft position sensor outputs a pulse signal.
- The ECM
DTC SET CONDITIONS
Check Conditions
- Engine speed is higher than 50 rpm.
Judgment Criteria
- Camshaft position sensor output voltage has not changed (no pulse signal is input) for 2 seconds.
Check Conditions
- Engine speed is higher than 50 rpm.
Judgment Criteria
- Normal signal pattern has not been input for cylinder identification from the crankshaft position sensor signal and camshaft position sensor signal for 2 seconds.
TROUBLESHOOTING HINTS (The most likely causes for this code to be set are:)
- Camshaft position sensor failed.
- Open or shorted camshaft position sensor circuit, or loose connector.
- ECM failed.
- PCM failed.
DIAGNOSIS
Required Special Tool:
- MB991348: Test Harness Set
STEP 1. Using the oscilloscope, check the camshaft position sensor.
1. Disconnect the camshaft position sensor connector B-22, and connect test harness special tool (MB991348) in between. (A/T terminals should be connected.)
2. Connect the oscilloscope probe to the camshaft position sensor side connector terminal No.5.
NOTE: When measuring with the ECM
3. Start the engine and run at idle.
4. Check the waveform.
- The waveform should show a pattern similar to the illustration.
5. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the waveform normal?
YES: Go to Step 2.
NO: Go to Step 4.
STEP 2. Check connector B-22 at camshaft position sensor for damage.
Q: Is the connector in good condition?
YES: Go to Step 3.
NO: Repair or replace it. Refer to Harness Connector Inspection. Then go to Step 20.
STEP 3. Check the trouble symptoms.
1. Carry out a test drive with the drive cycle pattern. Refer to Trouble Code Diagnosis - OBD-II Drive Cycle - Procedure 6 - Other Monitor.
2. Check the diagnostic trouble code (DTC).
Q: Is DTC P0340 set?
YES: Replace the ECM
NO: It can be assumed that this malfunction is intermittent. Refer to INTRODUCTION, How to Use Troubleshooting/Inspection Service Points.
Connectors:
STEP 4. Check connector B-22 at camshaft position sensor for damage.
Q: Is the connector in good condition?
YES: Go to Step 5.
NO: Repair or replace it. Refer to Harness Connector Inspection. Then go to Step 20.
Connectors:
STEP 5. Measure the sensor supply voltage at camshaft position sensor connector B-22.
1. Disconnect the connector B-22 and measure at the harness side.
2. Turn the ignition switch to the "ON" position.
3. Measure the voltage between terminal No.5 and ground.
- Voltage should be between 4.8 and 5.2 volts.
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the measured voltage between 4.8 and 5.2 volts?
YES: Go to Step 10.
NO: Go to Step 6.
Connectors:
STEP 6. Measure the sensor supply voltage at ECM connector C-118
1. Do not disconnect the ECM connector C-118
2. Disconnect the camshaft position sensor connector B-22.
3. Turn the ignition switch to the "ON" position.
4. Measure the voltage between terminal No.50
- Voltage should be between 4.8 and 5.2 volts.
5. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the measured voltage between 4.8 and 5.2 volts?
YES: Go to Step 7.
NO: Go to Step 8.
Connectors:
STEP 7. Check connector C-118 at ECM
Q: Is the connector in good condition?
YES: Repair harness wire between camshaft position sensor connector B22 (terminal No.5) and ECM connector C-118 (terminal No.50)
NO: Repair or replace it. Refer to Harness Connector Inspection. Then go to Step 20.
Connectors:
STEP 8. Check connector C-118 at ECM
Q: Is the connector in good condition?
YES: Go to Step 9.
NO: Repair or replace it. Refer to Harness Connector Inspection. Then go to Step 20.
Connectors:
STEP 9. Check for short circuit to ground between camshaft position sensor connector B-22 (terminal No.5) and ECM connector C-118 (terminal No.50)
Q: Is the harness wire in good condition?
YES: Replace the ECM or PCM. Then go to Step 20.
NO: Repair it. Then go to Step 20.
STEP 10. Measure the power supply voltage at camshaft position sensor connector B-22.
1. Disconnect the connector B-22 and measure at the harness side.
2. Turn the ignition switch to the "ON" position.
3. Measure the voltage between terminal No.6 and ground.
- Voltage should be battery positive voltage.
4. Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is battery positive voltage (approximately 12 volts) present?
YES: Go to Step 12.
NO: Go to Step 11.
STEP 11. Check connector A-18X at MFI relay for damage.
Q: Is the connector in good condition?
YES: Repair harness wire between MFI relay connector A-18X (terminal No.4) and camshaft position sensor connector B-22 (terminal No.6) because of open circuit or short circuit to ground. Then go to Step 20.
NO: Repair or replace it. Refer to Harness Connector Inspection. Then go to Step 20.
STEP 12. Check the continuity at camshaft position sensor connector B-22.
1. Disconnect the connector B-22 and measure at the harness side.
2. Check for the continuity between terminal No.7 and ground.
- Should be less than 2 ohms.
Q: Is the continuity normal?
YES: Go to Step 15.
NO: Go to Step l3.
Connectors:
STEP 13. Check connector C-111 at ECM
Q: Is the connector in good condition?
YES: Go to Step 14.
NO: Repair or replace it. Refer to Harness Connector Inspection. Then go to Step 20.
Connectors:
STEP 14. Check for open circuit and harness damage between camshaft position sensor connector B-22 (terminal No.?) and ECM connector C-111 (terminal No.34)
Q: Is the harness wire in good condition?
YES: Replace the ECM or PCM. Then go to Step 20.
NO: Repair it. Then go to Step 20.
STEP 15. Check connector A-18X at the MFI relay for damage.
Q: Is the connector in good condition?
YES: Go to Step 16.
NO: Repair or replace it. Refer to Harness Connector Inspection. Then go to Step 20.
STEP 16. Check connector C-118 at ECM
Q: Is the connector in good condition?
YES: Go to Step 17.
NO: Repair or replace it. Refer to Harness Connector Inspection. Then go to Step 20.
STEP 17. Check for harness damage between MFI relay connector A-18X (terminal No.4) and camshaft position sensor connector B-22 (terminal No.6).
Q: Is the harness wire in good condition?
YES: Go to Step 18.
NO: Repair it. Then go to Step 20.
Connectors:
STEP 18. Check for harness damage between camshaft position sensor connector B-22 (terminal No.5) and ECM connector C-118 (terminal No.50)
Q: Is the harness wire in good condition?
YES: Go to Step 19.
NO: Repair it. Then go to Step 20.
STEP 19. Check the distributor installation.
Q: Is the distributor installation in a good condition?
YES: Replace the distributor. Then go to Step 20.
NO: Repair it. Then go to Step 20.
STEP 20. Test the OBD-III drive cycle.
1. Carry out a test drive with the drive cycle pattern. Refer to Trouble Code Diagnosis - OBD-III Drive Cycle - Procedure 6 - Other Monitor
2. Check the diagnostic trouble code (DTC).
Q: Is DTC P0340 set?
YES: Retry the troubleshooting.
NO: The inspection is complete.