Dtc P0340 Camshaft Position Sensor Circuit Malfunction

Engine. Lexus Gs430, Gs300. Uzs190 Grs190
3Gr-Fe Engine Control System. Lexus Gs430, Gs300. Uzs190 Grs190

DESCRIPTION

MONITOR DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK ECM TERMINAL VOLTAGE

CHECK VVT SENSOR FOR INTAKE CAMSHAFT (SENSOR POWER SOURCE)

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

CHECK SENSOR INSTALLATION (VVT SENSOR FOR INTAKE CAMSHAFT)

CHECK CAMSHAFT TIMING GEAR ASSEMBLY (TEETH OF PLATE)

DTC P0340 Camshaft Position Sensor Circuit Malfunction

DTC P0342 Camshaft Position Sensor "A" Circuit Low Input (Bank 1 or Single Sensor)

DTC P0343 Camshaft Position Sensor "A" Circuit High Input (Bank 1 or Single Sensor)

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

DTC P0347 Camshaft Position Sensor "A" Circuit Low Input (Bank 2)

DTC P0348 Camshaft Position Sensor "A" Circuit High Input (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 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.

DTC No.
DTC Detection Condition
Trouble Area
P0340
P0345
  1. Input voltage to ECM remains 0.3 V or less, or 4.7 V or higher for more than 5 seconds, when 2 more seconds have elapsed after turning engine switch on (IG)
    (1 trip detection logic)
  2. No VVT sensor signal to ECM during cranking
    (1 trip detection logic)
  1. Open or short in VVT sensor for intake camshaft circuit
  2. VVT sensor for intake camshaft
  3. Camshaft timing gear for intake camshaft
  4. Jumped tooth of timing chain for intake camshaft
  5. ECM
P0342
P0347
Output voltage of VVT sensor 0.3 V or less for 5 seconds
(1 trip detection logic)
  1. Open or short in VVT sensor for intake camshaft circuit
  2. VVT sensor for intake camshaft
  3. Camshaft timing gear for intake camshaft
  4. Jumped tooth of timing chain for intake camshaft
  5. ECM
P0343
P0348
Output voltage of VVT sensor 4.7 V or more for 5 seconds
(1 trip detection logic)
  1. Open or short in VVT sensor for intake camshaft circuit
  2. VVT sensor for intake camshaft
  3. Camshaft timing gear for intake camshaft
  4. Jumped tooth of timing chain for intake camshaft
  5. ECM
Lexus Gs430, Gs300. Uzs190 Grs190.3Gr-Fe Engine Control System.Sfi System. Dtc P0340 Camshaft Position Sensor Circuit Malfunction
  1. Reference: Inspection using an oscilloscope
HINT:
  1. The correct waveform is shown.
  2. VV1+ and VV2+ stand for the VVT sensor signal, and NE+ stands for the CKP sensor signal.
Item
Content
Terminals
NE+ - NE-
VV1+ - VV1-
VV2+ - VV2-
Equipment Settings
5 V/DIV., 20 msec./DIV.
Conditions
Cranking or idling

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.

WIRING DIAGRAM

Refer to DTC P0335 on page Click here.

INSPECTION PROCEDURE

HINT:
Read freeze frame data using the intelligent tester. Freeze frame data records the engine conditions when a malfunction is detected. 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.
1.CHECK ECM TERMINAL VOLTAGE
Lexus Gs430, Gs300. Uzs190 Grs190.3Gr-Fe Engine Control System.Sfi System. Dtc P0340 Camshaft Position Sensor Circuit Malfunction

  1. Inspect the ECM using an oscilloscope.

    1. While the engine is idling, check the waveform between the terminals of the ECM connector.

      Standard voltage:
      Tester Connection
      		Specified Condition
      VV1+ (E8-21) - VV1- (E8-20)
      		Correct waveform shown
      VV2+ (E8-19) - VV2- (E8-18)
      		Correct waveform shown
      NE+ (E8-32) - NE- (E8-31)
      		Correct waveform shown


NG
REPLACE VVT SENSOR
OK


2.CHECK VVT SENSOR FOR INTAKE CAMSHAFT (SENSOR POWER SOURCE)
Lexus Gs430, Gs300. Uzs190 Grs190.3Gr-Fe Engine Control System.Sfi System. Dtc P0340 Camshaft Position Sensor Circuit Malfunction

  1. Disconnect the E34 or E15 VVT sensor connector.

  1. Measure the voltage between the terminals of the wire harness side connector and body ground.

    Standard voltage:
    Tester Connection
    		Specified Condition
    VC (E34-3) - Body ground
    		4.5 to 5.0 V
    VC (E15-3) - Body ground
    		4.5 to 5.0 V

  1. Reconnect the VVT sensor connector.



NG
REPAIR OR REPLACE HARNESS AND CONNECTOR
OK


3.CHECK HARNESS AND CONNECTOR (VVT SENSOR FOR INTAKE CAMSHAFT - ECM)
Lexus Gs430, Gs300. Uzs190 Grs190.3Gr-Fe Engine Control System.Sfi System. Dtc P0340 Camshaft Position Sensor Circuit Malfunction

  1. Disconnect the E34 or E15 VVT sensor connector.

  1. Disconnect the E8 ECM connector.

  1. Measure the resistance.

    Standard resistance (Check for open):
    Tester Connection
    		Specified Condition
    VVR+ (E34-1) - VV1+ (E8-21)
    		Below 1 Ω
    VVR- (E34-2) - VV1- (E8-20)
    		Below 1 Ω
    VVL+ (E15-1) - VV2+ (E8-19)
    		Below 1 Ω
    VVL- (E15-2) - VV2- (E8-18)
    		Below 1 Ω
    Standard resistance (Check for short):
    Tester Connection
    		Specified Condition
    VVR+ (E34-1) or VV1+ (E8-21) - Body ground
    		10 kΩ or higher
    VVR- (E34-2) or VV1- (E8-20) - Body ground
    		10 kΩ or higher
    VVL+ (E15-1) or VV2+ (E8-19) - Body ground
    		10 kΩ or higher
    VVL- (E15-2) or VV2- (E8-18) - Body ground
    		10 kΩ or higher

  1. Reconnect the VVT sensor connector.

  1. Reconnect the ECM connector.



NG
REPAIR OR REPLACE HARNESS AND CONNECTOR
OK


4.CHECK SENSOR INSTALLATION (VVT SENSOR FOR INTAKE CAMSHAFT)
Lexus Gs430, Gs300. Uzs190 Grs190.3Gr-Fe Engine Control System.Sfi System. Dtc P0340 Camshaft Position Sensor Circuit Malfunction

  1. Check the CKP sensor installation.

    OK:
    Sensor is installed correctly.


NG
TIGHTEN SENSOR
OK


5.CHECK CAMSHAFT TIMING GEAR ASSEMBLY (TEETH OF PLATE)

  1. 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