P0340

2UZ-FE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0340: Camshaft Position Sensor Circuit Malfunction

DTC P0340 - Camshaft Position Sensor Circuit Malfunction

DTC P0345 - Camshaft Position Sensor "A" Circuit (Bank 2)

DESCRIPTION

The Variable Valve Timing (VVT) sensor consists of a magnet, iron core and pickup coil. The VVT signal plate has 3 teeth on its outer circumference and is installed on the camshaft timing pulley. When the camshafts rotates, changes occur on the camshaft protrusions and the pickup coil air gaps. These changes cause fluctuations in the magnetic field and generate voltage in the pickup coil.
Each sensor monitors its timing rotor, which is located on the camshaft. The ECM uses the sensor to detect the camshaft angle. The camshaft rotation synchronizes with the crankshaft rotation, and this sensor communicates the rotation of the camshaft timing rotor as a pulse signal to the ECM. Based on the signal, the ECM controls camshaft position.
The crankshaft angle sensor plate has 34 teeth. The pickup coil generates 34 signals for each engine revolution. Based on a combination of the VVT signal and NE signal, the ECM detects the crankshaft angle. Then the ECM uses this data to control fuel injection time and injection timing. Also, based on the NE signal, the ECM detects the engine speed.





- Reference: Inspection using an oscilloscope





HINT:
- The correct waveform is as shown.
- VV1+ and VV2+ stand for the VVT sensor signal, and NE+ stands for the CKP sensor signal.





MONITOR DESCRIPTION

If no signal is transmitted by the VVT sensor despite the engine revolving, the ECM interprets this as a malfunction of the sensor.

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS

All:





Case 1:





Case 2:





TYPICAL MALFUNCTION THRESHOLDS





COMPONENT OPERATING RANGE





WIRING DIAGRAM





INSPECTION PROCEDURE

HINT: Read freeze frame data using the Techstream. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air-fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction (Freeze Frame Data).

PROCEDURE

1. INSPECT VVT SENSOR (RESISTANCE)





(a) Disconnect the D36 or D38 VVT sensor connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:





NOTE: In the above chart, the terms "cold" and "hot" refer to the temperature of the coils.

"Cold" means approximately -10 to 50°C (14 to 122°F).
"Hot" means approximately 50 to 100°C (122 to 212°F).
NG -- REPLACE VVT SENSOR
OK -- Continue to next step.
2. CHECK HARNESS AND CONNECTOR (VVT SENSOR - ECM)





(a) Disconnect the D36 or D38 VVT sensor connector.
(b) Disconnect the D74 ECM connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
3. CHECK SENSOR INSTALLATION (VVT SENSOR)





(a) Check the VVT sensor installation.
OK:
Sensor is installed correctly.
NG -- SECURELY REINSTALL SENSOR
OK -- Continue to next step.
4. CHECK CAMSHAFT (TEETH)
(a) Remove the cylinder head cover (Disassembly).
(b) Check the tooth of the camshaft.
OK:
The camshaft does not have any cracks or deformation.
NG -- REPLACE CAMSHAFT
OK -- Continue to next step.
5. REPLACE VVT SENSOR
(a) Replace the VVT sensor (Removal).
NEXT -- Continue to next step.
6. 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.
(e) Start the engine.
(f) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes / Pending.
(g) Read DTCs.

Result





HINT: If the engine does not start, replace the ECM.

B -- REPLACE ECM
A -- END