2001 TOYOTA AVALON Service Repair Manual

A11423
Engine Room J/B
AM2
Fuse
DI-122
- DIAGNOSTICSENGINE
278 Author
: Date
:
2001 AVALON (RM808U)
10 Check AM2 fuse.
PREPARATION:
Remove the AM2 fuse from the engine room J/B.
CHECK:
Check the continuity of the AM2 fuse.
OK:
Continuity
NG Check for short in all harness and components
connected to AM2 fuse.
OK
11 Check ignition relay (Marking: IG2) (See page IG-10).
NG Replace ignition relay.
OK
Replace ignition coil with igniter.

- DIAGNOSTICSENGINE
DI-123
279 Author
: Date
:
2001 AVALON (RM808U)
DTC P1335 Crankshaft Position Sensor Circuit Malfunc-
tion (During engine running)
CIRCUIT DESCRIPTION
Refer to DTC P0335 on page DI-67.
DTC No.DTC Detecting ConditionTrouble Area
P1335No crankshaft position sensor signal to ECM with engine
speed 1,000 rpm or more

Open or short in crankshaft position sensor circuit

Crankshaft position sensor

Crankshaft timing pulley

ECM
WIRING DIAGRAM
Refer to DTC P0335 on page DI-67.
INSPECTION PROCEDURE
Refer to DTC P0335 on page DI-67.
HINT:
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.
DI085-09

A11663
VV1, VV2 and NE Signal Waveforms2 V
/Division
20 msec./Division (Idling)
VV1
NE VV2GND
GND
GND
DI-124
- DIAGNOSTICSENGINE
280 Author
: Date
:
2001 AVALON (RM808U)
DTC P1345 VVT Sensor/Camshaft Position Sensor Cir-
cuit Malfunction (Bank 1)
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 ConditionTrouble 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
P1350No VVT sensor (Camshaft position sensor) signal to ECM with
5 sec. or more engine speed 600 rpm or morecuit

VVT sensor (camshaft position sensor)

Camshaft timing gearP1350
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-67.
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.
DI6T9-01

- DIAGNOSTICSENGINE
DI-125
281 Author
: Date
:
2001 AVALON (RM808U)
OK
2 Check for open and short in harness and connector between ECM and VVT sen-
sor (See page IN-30).
NG Repair or replace harness or connector.
OK
3 Inspect sensor installation and signal plate teeth of camshaft timing gear.
NG Tighten sensor. Replace camshaft timing gear.
OK
Check and replace ECM (See page IN-30).

DI-126
- DIAGNOSTICSENGINE
282 Author
: Date
:
2001 AVALON (RM808U)
DTC P1346 VVT Sensor/Camshaft Position Sensor Cir-
cuit Range/Performance Problem (Bank 1)
DTC P1351 VVT Sensor/Camshaft Position Sensor Cir-
cuit Range/Performance Problem (Bank 2)
CIRCUIT DESCRIPTION
Refer to DTC P1345, P1350 on page DI-124.
DTC No.DTC Detection ConditionTrouble Area
P1346Deviation in crankshaft position sensor signal and VVT sensor
(bank 1) signal (2 trip detection logic)
Mechanical system malfunction (Jumping teeth of timing belt,
blt t thd)
P1351Deviation in crankshaft position sensor signal and VVT sensor
(bank 2) signal (2 trip detection logic)belt stretched)

ECM
WIRING DIAGRAM
Refer to DTC P1345, P1350 on page DI-124.
INSPECTION PROCEDURE
HINT:
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 valve timing (Check for loose and jumping teeth of timing belt) (See page
EM-15).
NG Adjust valve timing (Repair or replace timing
belt).
OK
Check and replace ECM (See page IN-30).
DI6TA-01

A07621A09776
Right Bank OCV
1
2R-B
RECM
OC1+
OC1-
OC2+
OC2- 29
18 Left Bank OCV
R-WR-L 1
2E46
5
E4
E4
E4
- DIAGNOSTICSENGINE
DI-127
283 Author
: Date
:
2001 AVALON (RM808U)
DTC P1349 VVT System Malfunction (Bank 1)
DTC P1354 VVT System Malfunction (Bank 2)
CIRCUIT DESCRIPTION
VVT system controls the intake valve timing to proper timing in response to driving condition.
ECM controls Oil Control Valve (OCV) to make the intake valve timing properly, and, oil pressure controlled
with OCV is supplied to the VVT controller, and then, VVT controller changes relative position between the
camshaft and the crankshaft.
DTC No.DTC Detecting ConditionTrouble Area
P1349
P1354
Condition (a) or (b) continues for after the engine is warmed up
and engine speed at 400 - 4,000 rpm:
(a) Valve timing does not change from of current valve timing
(b) Current valve timing is fixed
Valve timing

OCV

VVT controller assembly

ECM
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:

If DTC P1349 is displayed, check left bank VVT system circuit.

If DTC P1354 is displayed, check right bank VVT system 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.
DI6TB-01

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).

- DIAGNOSTICSENGINE
DI-129
285 Author
: Date
:
2001 AVALON (RM808U)
OK
4 Check VVT controller assembly.
PREPARATION:
(a) Remove the timing belt (See page EM-15).
(b) Remove the cylinder head cover.
(c) Remove the OCV (See page EM-31).
(d) Drain oil into the VVT controller assembly (See page EM-31).
CHECK:
Check whether the oil into VVT controller assembly is drained or not.
OK:
The oil into VVT controller assembly is drained.
NG Replace VVT controller assembly, and then go
to step 5.
OK
5 Check OCV (See page SF-51).
NG Replace OCV, and then go to step 6.
OK
6 Check blockage of OCV, oil check valve and oil pipe No.1.
NG Repair or replace.
OK
7 Check whether or not DTC P1349/P1354 is stored.
PREPARATION:
(a) Clear the DTC (See page DI-3).
(b) Perform simulation test.