1996 TOYOTA T100 engine

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− DIAGNOSTICSAUTOMATIC TRANSMISSION
DI−289
1996 TOYOTA T100 (RM449U)
DTC P0750, P0755 Shift Solenoid A/B Malfunction (Shift
Solenoid Valve No.1/No.2)
SYSTEM DESCRIPTION
The ECM uses signals from the vehicle speed sensor to detect the actual gear position (1st, 2nd, 3rd or O/D
gear).
Then the ECM compares the actual gear with the shift schedule in the ECM memory to detect mechanical
trouble of the shift solenoid valves and valve body.
DTC No.DTC Detecting ConditionTrouble Area
P0750
P0755During normal driving, gear required by ECM does not match
actual gear
(2 trip detection logic)Shift solenoid valve No.1/No.2 is stuck open or closed
Valve body is blocked up or stuck
HINT:
Check the shift solenoid valve No.1 when DTC P0750 is output and check shift solenoid valve No.2 when
DTC P0755 is output.
INSPECTION PROCEDURE
1 Check shift solenoid valve No.1 or No.2 operation.
PREPARATION:
(a) Remove the oil pan.
(b) Remove the shift solenoid valve No.1 or No.2.
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.
NG Replace shift solenoid valve No.1 or No.2.
OK
2 Check valve body (See page DI−282).
NG Repair or replace valve body.
OK
Repair or replace transmission (See page
AT−26, AT−33).
DI0VM−01

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NORMALSHIFT SOLENOID NO.1
MALFUNCTIONING
Solenoid valveNo.1 No.2GearSHIFT SOLENOID NO.2
MALFUNCTIONINGBOTH SOLENOIDS
MALFUNCTIONINGSolenoid valve
No.1 No.2GearSolenoid valve
No.1 No.2GearGear when shift selector is
manually operated
D
2
LON
ONOFF
ON
ON
OFF
OFF OFF
ON
ONOFF
ON
ON OFF
ON
ON ONOFF1st
2nd
3rd
O/D
1st
2nd
3rd
1st
2ndX
X
X
X
X
X
X
X
XON
ON
OFF
OFFON
ON
ON3rd 3rd
O/D
3rd
3rd
1st
2ndX
X
X
X
X
X
X
X
X OFF
OFF
ON
ON OFF OFF
OFF
ON
ON1st
O/D
3rd1st O/D O/D
3rd
1st
1stO/D O/D O/D
O/D
3rd 3rd
3rd
1st
1st
X: MalfunctionsON
ON3rd
3rd
DI−290
− DIAGNOSTICSAUTOMATIC TRANSMISSION
1996 TOYOTA T100 (RM449U)
DTC P0753, P0758 Shift Solenoid A/B Electrical Malfunc-
tion (Shift Solenoid Valve No.1/No.2)
CIRCUIT DESCRIPTION
Shifting from 1st to O/D is performed in combination with ON and OFF of the shift solenoid valves No.1 and
No.2 controlled by ECM. If an open or short circuit occurs in either of the shift solenoid valves, the ECM con-
trols the remaining normal shift solenoid valve to allow the vehicle to be operated smoothly (Fail safe func-
tion).
Fail safe function:
If either of the shift solenoid valve circuits develops an open or short, the ECM turns the other shift solenoid
ON and OFF to shift to the gear positions shown in the table below. The ECM also turns the shift solenoid
valve SL OFF at the same time. If both solenoids are malfunction, hydraulic control cannot be performed
electronically and must be done manually.
Manual shifting as shown in the following table must be done (In the case of a short circuit, the ECM stops
sending current to the short circuited solenoid).
HINT:
Check the shift solenoid valve No.1 when DTC P0753 is output and check the shift solenoid valve No.2 when
DTC P0758 is output.
DTC No.DTC Detecting ConditionTrouble Area
P0753
P0758
ECM checks for open or short circuit in shift solenoid valves
No.1 and No.2 circuit when it changes
ECM records DTC P0753 or P0758 if condition (a) or (b) is
detected once, but it does not light up MIL
After ECM detects condition (a) or (b) continuously 2 times or
more in one−trip, it causes MIL light up until condition (a) or (b)
disappears
After that, if ECM detects condition (a) or (b) once, it starts
lighting up MIL again:
(a) Solenoid resistance is 8 Ω or less (short circuit) when sole-
noid is energized
(b) Solenoid resistance is 100 kΩ or more (open circuit) when
solenoid is not energized
Open or short in shift solenoid valve No.1/No.2 circuit
Shift solenoid valve No.1/No.2
ECM
DI0VP−02

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ECM
B+
B+ S1
S2 E2
E2 Transmission
Shift Solenoid
Valve No.1
Shift Solenoid
Valve No.21
211
17*
1
*2
*1: 3RZ−FE
*2: 5VZ−FEW
B−W W
BE7
E7 10
9*
2*1
B−W
B−W
To Cruise Control ECU
Q07641
Q07642D00006
3RZ−FE
5VZ−FES2
S1
S2
S1
− DIAGNOSTICSAUTOMATIC TRANSMISSION
DI−291
1996 TOYOTA T100 (RM449U)
WIRING DIAGRAM
INSPECTION PROCEDURE
1 Measure resistance between terminal S1 or S2 of ECM connector and body
ground.
PREPARATION:
Disconnect the connector from the ECM.
CHECK:
Measure resistance between terminal S1 or S2 of ECM connec-
tor and body ground.
OK:
Resistance: 11 − 15 Ω
OK Check and replace ECM.
NG

Downloaded from www.Manualslib.com manuals search engine Q07643
Q07644
Q05336
D00007
3RZ−FE
5VZ−FES2
S1 S2
S1
S1
S2
S2
S1
S1
DI−292
− DIAGNOSTICSAUTOMATIC TRANSMISSION
1996 TOYOTA T100 (RM449U)
2 Check harness and connector between ECM connector and automatic transmis-
sion solenoid connector.
PREPARATION:
Disconnect the solenoid connector from the automatic trans-
mission.
CHECK:
Check the harness and connector between terminal S1 or S2
of ECM connector and terminal S1 or S2 of solenoid connector.
OK:
There is no open and no short circuit.
NG Repair or replace harness or connector.
OK

Downloaded from www.Manualslib.com manuals search engine Q07645
Q07646D00005
− DIAGNOSTICSAUTOMATIC TRANSMISSION
DI−293
1996 TOYOTA T100 (RM449U)
3 Check shift solenoid valve No.1 or No.2.
PREPARATION:
(a) Remove the oil pan.
(b) Remove the shift solenoid valve No.1 or No.2.
CHECK:
(a) Measure resistance between solenoid connector and so-
lenoid body.
(b) Connect positive lead to terminal of solenoid connector,
negative lead to solenoid body.
OK:
(a) Resistance: 11 − 15 Ω
(b) The solenoid makes an operating noise.
NG Replace solenoid valve.
OK
Repair or replace solenoid wire.

Downloaded from www.Manualslib.com manuals search engine Q06995
Drain
Line
Pressure
Q07640
DI−294
− DIAGNOSTICSAUTOMATIC TRANSMISSION
1996 TOYOTA T100 (RM449U)
DTC P0770 Shift Solenoid E Malfunction
(Shift Solenoid Valve SL)
SYSTEM DESCRIPTION
The ECM uses the signals from the Throttle position sensor,
mass air flow meter and crankshaft position sensor to monitor
the engagement 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 and torque converter clutch.
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)Shift solenoid valve SL is stuck open or closed
Valve body blocked up or stuck
Lock−up clutch
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 voltage is supplied to the shift solenoid
valve, check that the solenoid valve opens.
NG Replace solenoid valve SL.
OK
DI0VR−01

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DI−295
1996 TOYOTA T100 (RM449U)
2 Check valve body (See page DI−282).
NG Repair or replace valve body.
OK
Replace torque converter clutch
(See page AT−26, AT−33).

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Transmission
Shift Solenoid
Valve SL
Y
E23
Y−BB+
SL 27 8
E7
E7
*1 *2
*1: 3RZ−FE
*2: 5VZ−FEECM DI−296
− DIAGNOSTICSAUTOMATIC TRANSMISSION
1996 TOYOTA T100 (RM449U)
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.Detection ItemDTC Detecting ConditionTrouble Area
P0773
Either (a) or (b) are detected for 1 time:
(2 trip detection logic)
(a) Solenoid resistance is 8 Ω or less (short circuit) when sole-
noid is energized
(b) Solenoid resistance is 100 kΩ or more (open circuit) when
solenoid is not energized
Open or short in shift solenoid valve SL circuit
Shift solenoid valve SL
ECM
WIRING DIAGRAM
DI0VU−01