TOYOTA AVALON 2001 Service Repair Manual
Page 751 of 1897
Q04874
Controlled
Pressure
Drain Controlled
Pressure Line
Pressure
Q08040D02461
(+)
(+)
(-) (-)
- DIAGNOSTICSAUTOMATIC TRANSAXLE
DI-187
343 Author: Date:
2001 AVALON (RM808U)
DTC P0770 Shift Solenoid E Malfunction
(Shift Solenoid Valve SL)
SYSTEM DESCRIPTION
The ECM uses the signals from the throttle position sensor, air-
flow meter and crankshaft position sensor to monitor the en-
gagement condition of the lock-up clutch.
Then the ECM compares the engagement condition of the
lock-up clutch with the lock-up schedule in the ECM memory
to detect mechanical trouble of the shift solenoid valve SL,
valve body, torque converter clutch or automatic transaxle
(clutch, brake or gear etc.).
DTC No.DTC Detecting ConditionTrouble Area
P0770
Lock-up does not occur when driving in the lock-up range
(normal driving at 80 km/h [50 mph]), or lock-up remains ON
in the lock-up OFF range.
(2-trip detection logic)
When lock-up is ON, clutch or brake slips or gear is broken.Shift solenoid valve SL is stuck open or closed
Valve body blocked up or stuck
Lock-up clutch
Automatic transaxle (clutch, brake or gear etc.)
INSPECTION PROCEDURE
1 Check solenoid valve SL operation.
PREPARATION:
(a) Remove the oil pan.
(b) Remove the shift solenoid valve SL.
CHECK:
(a) Applying 490 kPa (5 kgf/cm2, 71 psi) of compressed air,
check that the solenoid valve does not leak air.
(b) When battery positive voltage is supplied to the shift sole-
noid valve, check that the solenoid valve opens.
OK:
(a) Solenoid valve does not leak air.
(b) Solenoid valve opens.
NG Replace the solenoid valve SL.
OK
DI02M-08
Page 752 of 1897
DI-188
- DIAGNOSTICSAUTOMATIC TRANSAXLE
344 Author: Date:
2001 AVALON (RM808U)
2 Check valve body (See page DI-175).
NG Repair or replace the valve body.
OK
3 Check the torque converter clutch (See page AX-43).
NG Replace the torque converter clutch.
OK
Repair the transaxle (See page AX-33).
Page 753 of 1897
D07906
E6 Transaxle
Shift Solenoid
Valve SL
2
SLG-W15
SLECM E1
- DIAGNOSTICSAUTOMATIC TRANSAXLE
DI-189
345 Author: Date:
2001 AVALON (RM808U)
DTC P0773 Shift Solenoid E Electrical Malfunction
(Shift Solenoid Valve SL)
CIRCUIT DESCRIPTION
The shift solenoid valve SL is turned ON and OFF by signals from the ECM to control the hydraulic pressure
acting on the lock-up relay valve, which then controls operation of the lock-up clutch.
Fail safe function:
If the ECM detects a malfunction, it turns the shift solenoid valve SL OFF.
DTC No.DTC Detecting ConditionTrouble Area
P0773
Either (a) or (b) is detected for 1 time.
(2-trip detection logic)
(a) Solenoid resistance is 8 W or less short when solenoid is
energized.
(b) Solenoid resistance is 100 kW or more when solenoid is not
energized.
Open or short in shift solenoid valve SL circuit
Shift solenoid valve SL
ECM
WIRING DIAGRAM
DI02N-08
Page 754 of 1897
D06559
SL
D06560
SLSL
DI-190
- DIAGNOSTICSAUTOMATIC TRANSAXLE
346 Author: Date:
2001 AVALON (RM808U)
INSPECTION PROCEDURE
1 Measure resistance between terminal SL of ECM and body ground.
PREPARATION:
(a) Remove the glove compartment (See page BO-90).
(b) Disconnect the connector from ECM.
CHECK:
Measure resistance between terminal SL of ECM and body
ground.
OK:
Resistance: 11 - 15 W at 20 °C (68 °F)
OK Check and replace the ECM (See page IN-30).
NG
2 Measure resistance of harness and connector between ECM and automatic
transaxle solenoid connector.
PREPARATION:
Disconnect the solenoid connector from the transaxle.
CHECK:
Measure resistance of the harness and connector between ter-
minal SL of ECM and terminal SL of solenoid connector.
OK:
Resistance: 0 W
NG Repair or replace the harness or connector.
OK
Page 755 of 1897
D04449
(+)
(-)
- DIAGNOSTICSAUTOMATIC TRANSAXLE
DI-191
347 Author: Date:
2001 AVALON (RM808U)
3 Check shift solenoid valve SL.
PREPARATION:
(a) Jack up the vehicle.
(b) Remove the oil pan.
(c) Disconnect the shift solenoid valve SL connector.
(d) Remove the shift solenoid valve SL.
CHECK:
(a) Measure resistance between terminal SL of shift solenoid
valve and solenoid body.
(b) Connect positive lead to terminal of solenoid connec-
tor, negative lead to solenoid body.
OK:
(a) Resistance: 11 - 15 W at 20 °C (68 °F)
(b) The shift solenoid valve SL makes operation
noise.
NG Replace the shift solenoid valve SL.
OK
Replace or repair the solenoid wire, harness
and connector between ECM and automatic
transaxle solenoid connector.
Page 756 of 1897
DI-192
- DIAGNOSTICSAUTOMATIC TRANSAXLE
348 Author: Date:
2001 AVALON (RM808U)
DTC P1520 Stop Light Switch Signal Malfunction
CIRCUIT DESCRIPTION
The purpose of this circuit is to prevent the engine from stalling, while driving in lock-up condition, when
brakes are suddenly applied.
When the brake pedal is operated, this switch sends a signal to ECM. Then the ECM cancels operation of
the lock-up clutch while braking is in progress.
DTC No.DTC Detecting ConditionTrouble Area
P1520No stop light switch signal to ECM during driving.
(2-trip detection logic)Open or short in stop light switch circuit
Stop light switch
ECM
WIRING DIAGRAM
See page DI-134.
INSPECTION PROCEDURE
See page DI-134.
DI02O-06
Page 757 of 1897
Q04869
NC2 Revolution Sensor
D07907
E4
E4 1O1 2
G R
Direct Clutch
Speed Sensor24
NC2+
ECM
NC2
-
23
- DIAGNOSTICSAUTOMATIC TRANSAXLE
DI-193
349 Author: Date:
2001 AVALON (RM808U)
DTC P1705 NC2 Revolution Sensor Circuit Malfunction
(Direct Clutch Speed Sensor)
CIRCUIT DESCRIPTION
This sensor detects the rotation speed of the direct clutch drum.
By comparing the direct clutch speed signal with the vehicle
speed sensor signal, the ECM detects the shift timing of the
gears and appropriately controls the engine torque and hydrau-
lic pressure in response to various conditions, thus performing
smooth gear shifting.
DTC No.DTC Detecting ConditionTrouble Area
P1705
The ECM detects conditions (a), (b), (c), (d), (e) and (f) conti-
nuity for 4 secs. or more.
(2-trip detection logic)
(a) Gear change not being performed
(b) Gear position: 1st, 2nd 3rd or O/D
(c) T/M input shaft rpm: 300 rpm or less
(d) T/M output shaft rpm: 1,000 rpm or more
(e) Park/neutral position switch: OFF
(f) Shift solenoid valves No. 1, No. 2, SL and vehicle speed
sensor are in normal operation.
Open or short in direct clutch speed sensor circuit
Direct clutch speed sensor
ECM
WIRING DIAGRAM
DI02P-07
Page 758 of 1897
D06556
NC2+NC2-
Q08218
Magnet
DI-194
- DIAGNOSTICSAUTOMATIC TRANSAXLE
350 Author: Date:
2001 AVALON (RM808U)
INSPECTION PROCEDURE
1 Check resistance between terminals NC2+ and NC2- of ECM.
PREPARATION:
(a) Remove the glove compartment.
(b) Disconnect the connector from ECM.
CHECK:
Check resistance between terminals NC2+ and NC2- of ECM.
OK:
Resistance: 560 - 680 W at 20 °C (68 °F)
OK Check and replace the ECM (See page IN-30).
NG
2 Check direct clutch speed sensor.
PREPARATION:
Remove the Direct clutch speed sensor from transaxle.
CHECK:
(a) Measure resistance between terminals 1 and 2 of speed
sensor.
(b) Check voltage between terminals 1 and 2 of the speed
sensor when a magnet is put close to the front end of the
speed sensor then taken away quickly.
OK:
(a) Resistance: 560 - 680 W at 20 °C (68 °F)
(b) Voltage is generated intermittently.
HINT:
The voltage generated is extremely low.
NG Replace the direct clutch speed sensor.
OK
Check and repair the harness and connector
between ECM and direct clutch speed sensor
(See page IN-30).
Page 759 of 1897
AT5608
Accumulator Control Pressure
High
Electric Current (A) 0
1
D00060
(*) Duty Ratio
The duty ratio is the ratio of the period of continuity in one cycle.
For example, if A is the period of continuity in one cycle, and B is the period of non-continuity, then
D00062
Reference
Waveform between terminals SLN
+
and SLN- when engine is idling.
5 V / Div.
GND Waveform between terminals SLN
+
and SLN- during shift change.
5 V / Div.
GND
1 msec. / Div.1 msec. / Div.
- DIAGNOSTICSAUTOMATIC TRANSAXLE
DI-195
351 Author: Date:
2001 AVALON (RM808U)
DTC P1765Linear Solenoid for Accumulator Pressure Control
Circuit Malfunction (Shift Solenoid Valve SLN)
CIRCUIT DESCRIPTION
The shift solenoid valve SLN controls the hydraulic pressure
acting on the accumulator control valve when gears are shifted
and performs smooth gear shifting.
The ECM determines optimum operating pressure according to
the signals from the throttle position sensor, vehicle speed sen-
sor and direct clutch speed sensor and controls the volume of
current flow to the solenoid valve.
The amount of current to the solenoid is controlled by the (*)
duty ratio of ECM output signals, causing a momentary change
to the hydraulic pressure acting on the clutches during gear
shifting.
When the duty ratio is high, the hydraulic pressure acting on the
clutches is low.
DTC No.DTC Detecting ConditionTrouble Area
P1765
After the engine is warmed up, the current flows to the shift
solenoid valve SLN for 1 sec or more under condition (a) or
(b):
(a) Engine speed: 500 rpm or more
(b) Park/neutral position switch: ON (P or N position)
Open or short in shift solenoid valve SLN circuit
Shift solenoid valve SLN
ECM
DI02Q-07
Page 760 of 1897
D07911
Y P-L
SLN-
E4 E1
E4ECM
20
SLN+
19 Shift Solenoid
Valve SLN
4 1 Transaxle DI-196
- DIAGNOSTICSAUTOMATIC TRANSAXLE
352 Author: Date:
2001 AVALON (RM808U)
WIRING DIAGRAM