P0340
DTC P0340: Camshaft Position Sensor Circuit
CIRCUIT OPERATION
- The camshaft position sensor power is supplied from the ECM (terminal No. 9).
- Terminal No. 2 of the camshaft position sensor is grounded with ECM (terminal No.
30).
- A 5-volt voltage is applied on the camshaft position sensor output terminal (terminal No. 3) from the ECM (terminal No. 14). The camshaft position sensor generates a pulse signal when the output terminal is opened and grounded.
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 checks whether pulse signal is input while the engine is cranking.
DESCRIPTIONS OF MONITOR METHODS
- Crankshaft position sensor signal does not change.
- Crankshaft position sensor signal is not normal pattern.
MONITOR EXECUTION
Continuous
MONITOR EXECUTION CONDITIONS (Other monitor and Sensor)
Other Monitor (There is no temporary DTC stored in memory for the item monitored below)
- Not applicable
Sensor (The sensor below is determined to be normal)
- Not applicable
DTC SET CONDITIONS [Range/Performance problem - Alignment]
Logic Flow Chart
DTC SET CONDITIONS
Check Condition
- Engine is being cranked.
or
- Engine speed is higher than 500 r/min excluding during cranking.
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.
DTC SET CONDITIONS [Range/Performance problem - Circuit continuity]
Logic Flow Chart
Check Condition
- Engine is being cranked.
or
- Engine speed is higher than 500 r/min excluding during cranking.
Judgement Criterion
- Camshaft position sensor output voltage has not changed (no pulse signal is input) for 2 seconds.
OBD-II DRIVE CYCLE PATTERN
Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 22 Monitors, Trips, Drive Cycles and Readiness Codes.
TROUBLESHOOTING HINTS (The most likely causes for this code to be set are:)
- Crankshaft position sensor failed.
- Camshaft position sensing cylinder failed.
- Connector damage
- Harness damage
- ECM failed.
DIAGNOSIS
Required Special Tools:
- MB991709: Test Harness
- MB992110: Power Plant ECU Check Harness
STEP 1. Check harness connector B-112 at camshaft position sensor and harness connector B-10 at for damage.
Q. Is the harness connector in good condition?
YES Go to Step 2.
NO Repair it. Harness Connector Inspection.
Then go to Step 9.
STEP 2. Measure the sensor supply voltage at camshaft position sensor connector B-112.
(1)Disconnect the connector B-112 and measure at the harness side.
(2)Turn the ignition switch to the "ON" position.
(3)Measure the voltage between terminal No. 1 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 5.
NO Go to Step 3.
STEP 3. Measure the sensor supply voltage at ECM connector B-10 by using power plant ECU check harness special tool MB992110.
(1)Disconnect all ECM connectors. Connect the power plant ECU check harness special tool MB992110 between the separated connectors.
(2)Turn the ignition switch to the "ON" position.
(3)Measure the voltage between terminal No. 9 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 Repair harness wire between the camshaft position sensor connector B-112 (terminal No. 1) and the ECM connector B-10 (terminal No. 9) because of open circuit or harness damage.
Then go to step 6.
NO Go to Step 4.
STEP 4. Check for short circuit to ground between the camshaft position sensor connector B-112 and the ECM connector B-10.
(1)Disconnect the camshaft position sensor connector B-112 and the ECM connector B-10.
(2)Check for the camshaft position sensor connector B-112 (terminal No. 1) and ground.
- Not continuity.
Q. Is the harness wire in good condition?
YES Replace the ECM. When the ECM is replaced, register the ID code. Refer to ID registration procedure manual - ID codes registration judgement table [Vehicles with KOS] or ID registration procedure manual - ID codes registration judgement table [Vehicles with WCM]. Then go to step 9.
NO Repair it. Harness Connector Inspection.
Then go to Step 9.
STEP 5. Check for open circuit and short circuit to ground between the camshaft position sensor connector B-112 and the ECM connector B-10.
(1)Disconnect the camshaft position sensor connector B-112 and the ECM connector B-10.
(2)Measure the resistance between the camshaft sensor connector B-112 and the ECM connector B-10.
- Should be less than 2 ohms.
1. Connector B-112 (terminal No. 3) and Connector B-10 (terminal No. 14).
2. Connector B-112 (terminal No. 2) and Connector B-10 (terminal No. 30).
(3)Check for the camshaft position sensor connector B-112 (terminal No. 3) and ground.
- Not continuity.
Q. Is the harness wire in good condition?
YES Go to Step 6.
NO Repair it. Then go to Step 9.
STEP 6. Using the oscilloscope, check the camshaft position sensor.
(1)Disconnect the camshaft position sensor connector B-112, and connect test harness special tool (MB991709) between the separated connectors (All terminals should be connected).
(2)Connect the oscilloscope probe to the camshaft position sensor side connector terminal No. 3.
NOTE:
When measuring with the ECM side connector, disconnect all ECM connectors. Connect the check harness special tool (MB992110) between the separated connectors. then connector the oscilloscope probe to the check harness connector terminal No. 14.
(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 8.
NO Go to Step 7.
STEP 7. Check the camshaft position sensing cylinder.
Q. Is the camshaft position sensing cylinder in good condition?
YES Replace the camshaft position sensor. Then go to Step 8.
NO Repair it. Then go to Step 8.
STEP 8. Check the trouble symptoms.
(1)Carry out a test drive with the drive cycle pattern. Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 22 Monitors, Trips, Drive Cycles and Readiness Codes.
(2)Check the diagnostic trouble code (DTC).
Q. Is DTC P0340 set?
YES Replace the ECM. When the ECM is replaced, register the ID code. Refer to ID registration procedure manual - ID codes registration judgement table [Vehicles with KOS] or ID registration procedure manual - ID codes registration judgement table [Vehicles with WCM]. Then go to Step 9.
NO It can be assumed that this malfunction is intermittent. How to Cope With Intermittent Malfunctions.
STEP 9. 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 22 Monitors, Trips, Drive Cycles and Readiness Codes.
(2)Check the diagnostic trouble code (DTC).
Q. Is DTC P0340 set?
YES Retry the troubleshooting.
NO The inspection is complete.