diagnostic menu TOYOTA AVALON 2001 Service Repair Manual

A00307
ON
VSV is ON VSV is OFF
Air Filter Air
Air
E
FE
F
BE6653
FI7073 FI7074
DI-146
- DIAGNOSTICSENGINE
302 Author
: Date
:
2001 AVALON (RM808U)
INSPECTION PROCEDURE
TOYOTA hand-held tester:
1 Connect TOYOTA hand-held tester, and check operation of VSV for ACIS.
PREPARATION:
(a) Remove the fuse cover on the instrument panel.
(b) Connect the TOYOTA hand-held tester to the DLC3.
(c) Turn the ignition switch ON and TOYOTA hand-held tes-
ter main switch ON.
(d) Select the INTAKE CTRL VSV from the ACTIVE TEST
menu on the TOYOTA hand-held tester.
CHECK:
Check the operation of the VSV when the VSV is operated by
the TOYOTA hand-held tester.
OK:
VSV is ON:
Air from port E flows out through port F.
VSV is OFF:
Air from port E flows out through the air filter.
OK Check vacuum tank (See page SF-46).
NG
2 Check VSV for ACIS (See page SF-68).
NG Replace VSV for ACIS.
OK
3 Check for open and short in harness and connector between EFI main relay
(Marking: EFI) and ECM (See page IN-30).
NG Repair or replace harness or connector.
OK

A02397
OCV Signal Waveform
1 m sec./Division5 V/
Division
GND
(A) (A) (A)
DI-128
- DIAGNOSTICSENGINE
284 Author
: Date
:
2001 AVALON (RM808U)
TOYOTA hand-held tester:
1 Check valve timing (See page EM-15).
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-30).

DI-138
- DIAGNOSTICSENGINE
294 Author
: Date
:
2001 AVALON (RM808U)
DTC P1656 OCV Circuit Malfunction (bank 1)
DTC P1663 OCV Circuit Malfunction (bank 2)
CIRCUIT DESCRIPTION
Refer to DTC P1349, P1354 on page DI-127.
DTC No.DTC Detecting ConditionTrouble Area
P1656
P1663Open or short in oil control valve circuit

Open or short in OCV circuit

OCV

ECM
WIRING DIAGRAM
Refer to DTC P1349, P1354 on page DI-127.
INSPECTION PROCEDURE
HINT:

If DTC P1656 dysplayed, check left bank OCV circuit.

If DTC P1663 dysplayed, check right bank OCV circuit.

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.
TOYOTA hand-held tester:
1 Check OCV circuit.
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:
VVT system is OFF (OCV is OFF): Normal engine speed
VVT system is ON (OCV is ON): Rough idle or engine stalled
OK Check for intermittent problems
(See page DI-3).
NG
DI6TC-01