Toyota Sienna Service Manual: Camshaft Position Sensor "A" Circuit

DESCRIPTION

The intake camshaft's Variable Valve Timing (VVT) sensor (G signal) consists of a magnet and MRE (Magneto Resistance 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 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 it to the ECM.

The crankshaft angle sensor plate has 34 teeth. The pickup coil generates 34 signals for each engine revolution. Based on combination of the G 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 shown in the illustration.
• 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

TYPICAL MALFUNCTION THRESHOLDS

WIRING DIAGRAM

Refer to DTC P0335 (See page ES-222).

INSPECTION PROCEDURE

HINT:

Read freeze frame data using the intelligent tester. 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.

1 CHECK HARNESS AND CONNECTOR (SENSOR POWER SOURCE)

(a) Disconnect the C18 or C19 VVT sensor connector.

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

Standard voltage

(c) Reconnect the VVT sensor connector.

2 CHECK HARNESS AND CONNECTOR (VVT SENSOR - ECM)

(a) Disconnect the C18 or C19 VVT sensor connector.

(b) Disconnect the E11 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.

3 CHECK SENSOR INSTALLATION (VVT SENSOR)

(a) Check the VVT sensor installation condition.

OK: Sensor is installed correctly.

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.

5 REPLACE VVT SENSOR

(a) Replace the VVT sensor (See page ES-509).

6 CHECK WHETHER DTC OUTPUT RECURS

(a) Connect the intelligent tester to the DLC3.

(b) Turn the ignition switch to the ON position.

(c) Turn the intelligent tester on.

(d) Clear the DTCs.

(e) Select the following menu items: DIAGNOSIS / ENHANCED OBD II / DTC / INFO / PENDING CODES.

(f) Read the DTCs.

Result

HINT:

If the engine does not start, replace the ECM.

END

7 CHECK HARNESS AND CONNECTOR (VVT SENSOR - ECM)

(a) Disconnect the C18 or C19 VVT sensor connector.

(b) Disconnect the E9 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.

REPLACE ECM (See page ES-498)