P0340

3MZ-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 intake camshaft's Variable Valve Timing (VVT) sensor (G signal) consists of a magnet and MRE element.
The VVT camshaft drive gear has a sensor plate with 3 teeth on its outer circumference. When the gear rotates, changes occur in the air gaps between the sensor plate and pickup coil, which affects the magnet. As a result, the resistance of the MRE material fluctuates. The VVT sensor converts the gear rotation data to pulse signals, and uses the pulse signals to determine the camshaft angle, which it sends to the ECM. Then the ECM uses this data to control fuel injection time and injection timing.
The crankshaft angle sensor plate has 34 teeth. The pickup coil generates 34 signals for each engine revolution. Based on the G signal and actual crankshaft angle, the ECM detects the normal crankshaft angle. Also, based on the NE signal, the ECM detects the engine speed.









- Reference: Inspection using an oscilloscope

HINT:
- The correct waveform is 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, or the rotations of the camshaft and the crankshaft are not synchronized, the ECM interprets this as a malfunction of the sensor.

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS

All:





P0340:





P0345:





TYPICAL MALFUNCTION THRESHOLDS

P0340, P345:





P0340, P0345:





COMPONENT OPERATING RANGE





WIRING DIAGRAM





INSPECTION PROCEDURE

HINT: Read freeze frame data using 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 help determine if the vehicle was running or stopped, 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. CHECK ECU TERMINAL VOLTAGE (VV1+, VV2+, NE+ AND NE- TERMINALS)





(a) Inspect the ECM using an oscilloscope.
(1) While the engine is idling, check the waveform between the terminals of the ECM connector.
OK:





NG -- REPLACE VVT SENSOR
OK -- Continue to next step.
2. CHECK VVT SENSOR (SENSOR RESISTANCE)





(a) Disconnect the VVT sensor connector.
(b) Measure the resistance between the terminals of the sensor.
Standard resistance:





(c) Reconnect the VVT sensor connector.

HINT: In the above section, the terms "cold" and "hot" refer to the temperature of the coils. "Cold" means approximately -10°C to 50°C (14°F to 122°F). "Hot" means approximately 50°C to 100°C (122°F to 212°F).

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





(a) Disconnect the VVT sensor connector.
(b) Disconnect the ECM connector.
(c) Measure the resistance between the terminals of the VVT sensor and ECM.
Standard resistance:
Check for open
Check for short









(d) Reconnect the VVT sensor connector.
(e) Reconnect the ECM connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
4. CHECK SENSOR INSTALLATION (VVT SENSOR)





(a) Check the CKP sensor installation.
OK:
Sensor is installed correctly.
NG -- SECURELY REINSTALL SENSOR
OK -- Continue to next step.
5. CHECK CAMSHAFT TIMING GEAR ASSEMBLY (TEETH OF PLATE)
(a) Check the teeth of the signal plate.
OK:
Sensor plate teeth do not have any cracks or deformation.
NG -- REPLACE CAMSHAFT TIMING GEAR ASSEMBLY
OK -- REPLACE ECM