Toyota RM787U, Руководство по обслуживанию и ремонту

Страница: 668 / 1976

A11663
VV1, VV2 and NE Signal Waveforms
2 V
/Division
20 msec./Division (Idling)
VV1
NE
VV2
GND
GND
GND
DI-130
- DIAGNOSTICS ENGINE
284
Author: Date:
2001 SIENNA (RM787U)
DTC P1350 VVT Sensor/Camshaft Position Sensor Cir-
cuit Malfunction (Bank 2)
CIRCUIT DESCRIPTION
VVT sensor (VV signal) consists of a magnet, iron core and pickup coil.
The VV signal plate has 3 teeth on its outer circumference and is installed the camshaft timing gear.
When the camshafts rotate, the protrusion on the signal plate and the air gap on the pickup coil change,
causing fluctuations in the magnetic field and generating an electromotive force in the pickup coil.
The actual camshaft angle is detected by the VVT sensor and it provides feedback to the ECM to control
the intake valve timing in response to during condition.
DTC No. DTC Detecting Condition Trouble Area
No VVT sensor (Camshaft position sensor) signal to ECM
during cranking at 4 sec. or more
Open or short in VVT sensor (camshaft position sensor) cir-
P1345
P1350
No VVT sensor (Camshaft position sensor) signal to ECM with
5 sec. or more engine speed 600 rpm or more
cuit
VVT sensor (camshaft position sensor)
Camshaft timing gear
P1350
While crankshaft rotates twice, VVT sensor (Camshaft position
sensor) signal will be input to ECM 5 times.
Camshaft timing gear
ECM
WIRING DIAGRAM
Refer to DTC P0335 on page DI-65 .
INSPECTION PROCEDURE
HINT:
If DTC P1345 is displayed, check left bank VVT sensor (camshaft position sensor).
If DTC P1350 is displayed, check right bank VVT sensor (camshaft position sensor).
Read freeze frame data using TOYOTA hand-held tester or OBD II scan tool. Because freeze frame
records the engine conditions when the malfunction is detected. When troubleshooting, it is useful for
determining whether the vehicle was running or stopped, the engine was warmed up or not, the air-fuel
ratio was lean or rich, etc. at the time of the malfunction.
1 Check resistance of VVT sensor (See page IG-7 ).
Reference: INSPECTION USING OSCILLOSCOPE
During idling, check the waveforms between terminals VV1 and
NE+, and VV2 and NE- of the ECM connector.
HINT:
The correct waveforms are as shown.
The waveform frequency is shortened as the engine
speed becomes higher.
NG Replace VVT sensor.
OK
DI6T9-02