P0340
DTC P0340: Camshaft Position (CMP) Sensor Circuit MalfunctionWiring Diagram:
System Description
The CMP sensor located on the transmission side of cylinder head consists of the signal generator (photo transistors) and signal rotor (slits plate).
The signal generator generates Reference signal and Position signal through two types of slits in the slit plate which turns together with the camshaft.
Reference signal
The CMP sensor generates 4 pulses of signals each of while has a different waveform length while the camshaft makes one full rotation.
Based on these signals, ECM judges which cylinder piston is in the compression stroke.
Position signal
The CMP sensor generates 360 pulses of signals while the camshaft makes one full rotation (i.e., 1 pulse per 1 ° movement of the camshaft).
Based on these signals, ECM judges the waveform length of Reference signal, the engine speed and piston position.
DTC Detecting Condition And Trouble Area:
DTC Confirmation Procedure
NOTE:
Check to make sure that the following conditions are satisfied when using this DTC confirmation procedure.
- Intake air temp.: -14 °C, 6.8 °F or higher
- Altitude (barometric pressure): 2020 m, 6650 ft or less (540 mmHg, 72 kPa or more)
1. With ignition switch turned OFF, connect scan tool.
2. Turn ON ignition switch and clear DTC using scan tool.
3. Crank engine for 5 sec. or more.
4. Check DTC and pending DTC.
Step 1 - 6:
Step 7 - 14:
Step 15 - 16:
DTC Troubleshooting
Reference
Connect oscilloscope between C46 - 10 (Reference signal) or C46 - 22 (Position signal) and C45 - 26 and check CMP sensor signals.
[A] Reference waveform
CMP sensor signal at engine idling.
Measurement terminal
CH2: C46 - 10 to C45 - 26
CH1: C46 - 22 to C45 - 26
Oscilloscope setting
CH1: 2 V/DIV
CH2: 5 V/DIV
TIME: 20 ms/DIV
Measurement condition
- After warmed up to normal operating temperature (ECT approx. 95 °C, 203 °F)
- At engine idling
[B] Reference detail waveform
CMP sensor signal at engine idling.
Measurement terminal
CH2: C46 - 10 to C45 - 26
CH1: C46 - 22 to C45 - 26
Oscilloscope setting
CH1: 2 V/DIV
CH2: 5 V/DIV
TIME: 40 ms/DIV
Measurement condition
- After warmed up to normal operating temperature (ECT approx. 95 °C, 203 °F)
- At engine idling