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DTC P0340: Camshaft Position Sensor Circuit
 
 
 
 
CIRCUIT OPERATION
  • The camshaft position sensor power is supplied from the ECM terminal 5V.
  • Terminal CPIE of the camshaft position sensor is grounded with ECM terminal CPIE.
  • A 5-volt voltage is applied on the camshaft position sensor output terminal from the ECM terminal CPI. The camshaft position sensor generates a pulse signal when the output terminal is opened and grounded.
 
 
TECHNICAL DESCRIPTION
  • The camshaft position sensor detects the position of the intake camshaft and inputs the pulse signal to the ECM.
  • In response to the camshaft position sensor signal and the crankshaft position sensor signal, the ECM detects the compression top dead center of the No. 1 cylinder.
  • Also, in response to the camshaft position sensor signal, the ECM controls variable valve timing (V.V.T.).
 
 
DESCRIPTIONS OF MONITOR METHODS
  • Camshaft position sensor signal does not change.
  • Camshaft position sensor signal is not normal pattern.
 
 
MONITOR EXECUTION
  • Continuous
 
 
MONITOR EXECUTION CONDITIONS (Other monitor and Sensor)
Other Monitor (There is no temporary DTC set in memory for the item monitored below)
  • Not applicable
Sensor (The sensor below is determined to be normal)
  • Not applicable
 
 
DTC SET CONDITIONS <Circuit continuity>
Logic Flow Chart
Check Condition
  • More than 20 revolutions after the engine speed is higher than 500 r/min.
or
  • Engine speed is higher than 1,600 r/min.
Judgment Criterion
  • Camshaft position sensor output voltage has not changed (no pulse signal is input) for 2 seconds.
 
 
DTC SET CONDITIONS <Range/Performance problem - alignment>
Logic Flow Chart
Check Condition
  • More than 20 revolutions after the engine speed is higher than 500 r/min.
or
  • Engine speed is higher than 1,600 r/min.
Judgment 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.
 
 
FAIL-SAFE AND BACKUP FUNCTION
  • Engine runs in learned pattern until engine stops.
  • Does not control variable valve timing (V.V.T.).
 
 
OBD-II DRIVE CYCLE PATTERN
  • Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 1 .
 
 
TROUBLESHOOTING HINTS (The most likely causes for this code to be set are:)
  • Camshaft position sensor failed.
  • Open or shorted camshaft position sensor circuit, harness damage or connector damage.
  • Intake camshaft failed.
  • ECM failed.

 
 
DIAGNOSIS
Required Special Tools:
  • MB991709: Test Harness
  • MB992110: Power Plant ECU Check Harness
STEP 1. Using the oscilloscope, check the camshaft position sensor.
  • Continuous idling mode
  • Select lever position indicator: P
  • Voltage between terminal SGT and ground.
OK: Waveforms should be displayed on inspection procedure using an oscilloscope (Refer to ).
Is the wave pattern normal?
Go to Step 12.
Go to Step 2.
 
STEP 2. Measure the sensor supply voltage at camshaft position sensor connector.
(1) Disconnect the camshaft position sensor connector and measure at the harness side.
(2) Turn on the power supply mode of the electric motor switch.
(3) Measure the voltage between terminal CPI and ground.
  • Voltage should be between 4.9 and 5.1 volts.
(4) Turn off the power supply mode of the electric motor switch.
Is the measured voltage between 4.9 and 5.1 volts?
Go to Step 5.
Go to Step 3.
 
STEP 3. Measure the sensor supply voltage at ECM connector by using power plant ECU check harness special tool MB992110.
(1) Disconnect the all ECM connectors. Connect the power plant ECU check harness special tool MB992110 between the separated connectors.
(2) Disconnect the camshaft position sensor connector.
(3) Turn on the power supply mode of the electric motor switch.
(4) Measure the voltage between terminal CPI and ground.
  • Voltage should be between 4.9 and 5.1 volts.
(5) Turn off the power supply mode of the electric motor switch.
Is the measured voltage between 4.9 and 5.1 volts?
Repair or replace the connector(s), or check and repair the harness of open circuit in CPI line between camshaft position sensor connector and ECM connector. Then go to Step 13.
Go to Step 4.
 
STEP 4. Check of short circuit to ground in CPI line between camshaft position sensor connector and ECM connector.
Is the harness wire in good condition?
Go to Step 12.
Repair the connector(s) or wiring harness. Then go to Step 13.
 
STEP 5. Measure the power supply voltage at camshaft position sensor connector.
(1) Disconnect the camshaft position sensor connector and measure at the harness side.
(2) Turn on the power supply mode of the electric motor switch.
(3) Measure the voltage between terminal 5V and ground.
  • Voltage should be 12V starter battery positive voltage.
(4) Turn off the power supply mode of the electric motor switch.
Is 12V starter battery positive voltage (approximately 12 volts) present?
Go to Step 7.
Go to Step 6.
 
STEP 6. Check of short to ground and open circuit in 5V line between camshaft position sensor connector and ECM connector.
Is the harness wire in good condition?
Go to Step 12.
Repair the connector(s) or wiring harness. Then go to Step 13.
 
STEP 7. Check the continuity at camshaft position sensor connector.
(1) Disconnect the camshaft position sensor connector and measure at the harness side.
(2) Check for the continuity between terminal CPIE and ground.
  • Continuity (2 ohms or less).
Does continuity exist?
Go to Step 9.
Go to Step 8.
 
STEP 8. Check of open circuit and harness damage in CPIE line between camshaft position sensor connector and ECM connector.
Is the harness wire in good condition?
Go to Step 12.
Repair the connector(s) or wiring harness. Then go to Step 13.
 
STEP 9. Check of harness damage in 5V line between ECM connector and camshaft position sensor connector.
Is the harness wire in good condition?
Go to Step 10.
Repair the connector(s) or wiring harness. Then go to Step 13.
 
STEP 10. Check of harness damage in CPI line between ECM connector and camshaft position sensor connector.
Is the harness wire in good condition?
Go to Step 11.
Repair the connector(s) or wiring harness. Then go to Step 13.
 
STEP 11. Check the camshaft position sensing portion.
Is the camshaft position sensing portion in good condition?
Replace the camshaft position sensor. Then go to Step 13.
Replace the intake camshaft. Then go to Step 13.
 
STEP 12. Check the trouble symptoms.
(1) Carry out a test drive with the drive cycle pattern. Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 1 .
(2) Check the diagnostic trouble code (DTC).
Is DTC P0340 set?
Replace the ECM (Refer to Removal and Installation ). Then go to Step 13.
It can be assumed that this malfunction is intermittent. Refer to GROUP 00, How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions .
 
STEP 13. Test the OBD-II drive cycle.
(1) Carry out a test drive with the drive cycle pattern. Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 1 .
(2) Check the diagnostic trouble code (DTC).
Is DTC P0340 set?
Retry the troubleshooting.
The inspection is complete.