P0340
2AZ-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0340: Camshaft Position Sensor "A" Circuit (Bank 1 or Single Sensor)
DTC P0340 - Camshaft Position Sensor "A" Circuit (Bank 1 or Single Sensor)
DESCRIPTION
The Camshaft Position (CMP) sensor consists of a magnet and an iron core which is wrapped with copper wire, and is installed onto the cylinder head. When the camshaft rotates, each of 3 teeth on the camshaft passes through the CMP sensor. This activates the internal magnet in the sensor, generating a voltage in the copper wire. The camshaft rotation is synchronized with the crankshaft rotation. When the crankshaft turns twice, the voltage is generated 3 times in the CMP sensor. The generated voltage in the sensor acts as a signal, allowing the ECM to locate the camshaft position. This signal is then used to control ignition timing, fuel injection timing, and the VVT system.
HINT: DTC P0340 indicates a malfunction relating to the CMP sensor circuit (the wire harness between the ECM and CMP sensor, and the CMP sensor itself).
Reference: Inspection using an oscilloscope
HINT:
- The correct waveform is as shown in the illustration.
- G2+ stands for the CMP sensor signal, and NE+ stands for the Crankshaft Position (CKP) sensor signal.
- Grounding failure of the shielded wire may cause noise in waveforms.
MONITOR DESCRIPTION
If no signal is transmitted by the CMP sensor despite the engine revolving, or the rotation of the camshaft and the crankshaft is not synchronized, the ECM interprets this as a malfunction of the sensor.
If the malfunction is not repaired successfully, the DTC is set 10 seconds after the engine is next started.
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
All:
Camshaft Position Sensor Range Check:
Camshaft Position/Crankshaft Position Misalignment:
TYPICAL MALFUNCTION THRESHOLDS
Camshaft Position Sensor Range Check:
Camshaft Position/Crankshaft Position Misalignment:
COMPONENT OPERATING RANGE
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT: Read freeze frame data using the Techstream. Freeze frame data records the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.
PROCEDURE
1. INSPECT CAMSHAFT POSITION SENSOR (RESISTANCE)
(a) Disconnect the camshaft position sensor connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:
(c) Reconnect the camshaft position sensor connector.
NG -- REPLACE CAMSHAFT POSITION SENSOR
OK -- Continue to next step.
2. CHECK HARNESS AND CONNECTOR (CAMSHAFT POSITION SENSOR - ECM)
(a) Disconnect the camshaft position sensor connector.
(b) Disconnect the ECM connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance (Check for open):
Standard resistance (Check for short):
(d) Reconnect the ECM connector.
(e) Reconnect the camshaft position sensor connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
3. CHECK SENSOR INSTALLATION (CAMSHAFT POSITION SENSOR)
(a) Check the camshaft position sensor installation.
OK:
Sensor is installed correctly.
NG -- SECURELY REINSTALL SENSOR
OK -- Continue to next step.
4. CHECK VALVE TIMING P0011
NG -- ADJUST VALVE TIMING
OK -- Continue to next step.
5. INSPECT CAMSHAFT
(a) Check the teeth of the camshaft.
OK:
Camshaft teeth do not have any cracks or deformation.
NG -- REPLACE CAMSHAFT
OK -- Continue to next step.
6. REPLACE CAMSHAFT POSITION SENSOR
NEXT -- Continue to next step.
7. CHECK WHETHER DTC OUTPUT RECURS
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to ON.
(c) Turn the Techstream ON.
(d) Clear DTCs DTC Check / Clear.
(e) Start the engine.
(f) Select the following menu items: Powertrain / Engine and ECT / Trouble Codes.
(g) Read DTCs.
Result
HINT: If the engine does not start, replace the ECM.
B -- REPLACE ECM
A -- END