P0340

1GR-FE ENGINE CONTROL: SFI SYSTEM: P0340, P0342, P0343, P0345, P0347, P0348: Camshaft Position Sensor Circuit Malfunction


DESCRIPTION

The intake camshaft's Variable Valve Timing (VVT) sensor (VV1, VV2 signal) consists of a magnet and MRE (Magnetoresistive Element).

The camshaft timing 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 MRE, which affects the magnetic field. As a result, the resistance of the MRE material fluctuates. The VVT sensor converts the gear rotation data to pulse signals, uses the pulse signals to determine the camshaft angle, and sends the camshaft angle data to the ECM.

The crankshaft position sensor plate has 34 teeth. The pickup coil generates 34 signals for each crankshaft 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 waveforms are as shown.
* VV1+ and VV2+ are the VVT sensor signals, and NE+ is the crankshaft position sensor signal.





MONITOR DESCRIPTION

If no signal is transmitted by the VVT sensor despite the camshaft revolving, or the rotations of the camshaft and crankshaft are not synchronized, the ECM interprets this as a malfunction of the VVT sensor.

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS

P0340 (Cranking)





P0340 (Engine Running)





P0345 (Engine Running)





P0342, P0343 (Low Voltage, High Voltage)





P0347, P0348 (Low Voltage, High Voltage)





TYPICAL MALFUNCTION THRESHOLDS

P0340 (Cranking)





P0340 (Engine Running)





P0345 (Engine Running)





P0342 (Low Voltage)





P0343 (High Voltage)





P0347 (Low Voltage)





P0348 (High Voltage)





COMPONENT OPERATING RANGE





CONFIRMATION DRIVING PATTERN





1. Connect the Techstream to the DLC3.

2. Turn the ignition switch to ON and turn the Techstream on.

3. Clear DTCs (even if no DTCs are stored, perform the clear DTC operation).

4. Turn the ignition switch off and wait for at least 30 seconds.

5. Turn the ignition switch to ON and turn the Techstream on [A].

6. Start the engine.

7. Idle the engine for 10 seconds or more [B].

8. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes [C].

9. Read the pending DTCs.

HINT
* If a pending DTC is output, the system is malfunctioning.
* If a pending DTC is not output, perform the following procedure.

10. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

11. Input the DTC: P0340, P0342, P0343, P0345, P0347 or P0348.

12. Check the DTC judgment result.





HINT
* If the judgment result shows NORMAL, the system is normal.
* If the judgment result shows ABNORMAL, the system has a malfunction.
* If the judgment result shows INCOMPLETE or UNKNOWN, perform steps [B] and [C] again.

13. If no pending DTC is output, perform a universal trip and check for permanent DTCs Reading and Clearing Diagnostic Trouble Codes.

HINT
* If a permanent DTC is output, the system is malfunctioning.
* If no permanent DTC is output, the system is normal.

WIRING DIAGRAM

Refer to DTC P0335 SFI System.

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. CHECK TERMINAL VOLTAGE (SENSOR POWER SOURCE)

(a) Disconnect the VVT sensor connector.





(b) Measure the voltage according to the value(s) in the table below.

Standard Voltage:





Text in Illustration





(c) Reconnect the VVT sensor connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

2. CHECK HARNESS AND CONNECTOR (VVT SENSOR FOR INTAKE CAMSHAFT - ECM)

(a) Disconnect the VVT sensor connector.

(b) Disconnect the ECM connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





(d) Reconnect the VVT sensor connector.

(e) Reconnect the ECM connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

3. CHECK SENSOR INSTALLATION (VVT SENSOR FOR INTAKE CAMSHAFT)

(a) Check the VVT sensor installation.





OK:

Sensor is installed correctly.

NG -- SECURELY REINSTALL SENSOR Installation
OK -- Continue to next step.

4. 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 Disassembly
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 Reading and Clearing Diagnostic Trouble Codes.

(e) Start the engine.

(f) Enter the following menus: Powertrain / Engine and ECT / Trouble Code / Pending.

(g) Read DTCs.

Result





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

B -- REPLACE ECM Removal

A -- END