Toyota RM787U, Руководство по обслуживанию и ремонту

Страница: 662 / 1976

A02397
OCV Signal Waveform
1 m sec./Division
5 V/
Division
GND
(A) (A) (A)
DI-124
- DIAGNOSTICS ENGINE
278
Author: Date:
TOYOTA hand-held tester:
1 Check valve timing (See page EM-16 ).
NG Repair valve timing.
OK
2 Check operation of OCV.
PREPARATION:
(a)
Start the engine and warmed it up.
(b) Connect the TOYOTA hand-held tester and select the VVT from the ACTIVE TEST menu.
CHECK:
Check the engine speed when operate the OCV by the TOYOTA hand-held tester.
OK:
OCV is OFF: Normal engine speed
OCV is ON: Rough idle or engine stall
OK VVT system is OK.*
*: DTCs P1349 and P1354 are also output after the foreign ob-
ject is caught in some part of the system in the engine oil and
the system returns to normal in a short time. As ECM controls
so that foreign objects are ejected, there is no problem about
VVT. There is also no problem since the oil filter should get the
foreign object in the engine oil.
NG
3 Check voltage between terminals OCV+ and OCV- of ECM connector.
Reference: INSPECTION USING OSCILLOSCOPE
Turn the ignition switch ON, and check the waveform between
terminals OCV+ and OCV- of the ECM connector.
HINT:
The correct waveform is as shown.
The waveform frequency (A) is lengthened as the engine
speed becomes higher.
NG Check and replace ECM (See page IN-31 ).