
DI-1020
DIAGNOSTICS - AUTOMATIC TRANSMISSION (A750E for 1GR-FE)
DIDVE-01
DTC P0748 Pressure Control Solenoid "A" Electrical
(Shift Solenoid Valve SL1)
CIRCUIT DESCRIPTION
Shifting from 1st to 5th is performed in combination with "ON" and "OFF" operation of the shift solenoid valves
SL1, SL2, S1, S2 and SR which are controlled by the ECM. If an open or short circuit occurs in either of the
shift solenoid valves, the ECM controls the remaining normal shift solenoid valves to allow the vehicle to be
operated smoothly (See page DI-985).
DTC No. DTC Detection Condition Trouble Area
ECM checks for an open or short circuit in shift solenoid valves
S Open or short in shift solenoid valve SL1 circuit
SL1 (1-trip detection logic)
P0748 S Shift solenoid valve SL1
(a) When solenoid, duty ratio equal to 100%
S ECM
(b) When solenoid is not energized, duty ratio is less than 3%
MONITOR DESCRIPTION
This DTC indicates an open or short in the shift solenoid valve SL1 circuit. The ECM commands gearshift
by turning the shift solenoid valves "ON/OFF". When there is an open or short circuit in any shift solenoid
valve circuit, the ECM detects the problem and illuminates the MIL and stores the DTC. And the ECM per-
forms the fail-safe function and turns the other normal shift solenoid valves "ON/OFF". (In case of an open
or short circuit, the ECM stops sending current to the circuit.)
While driving and shifting between 4th and 5th gears, if the ECM detects an open or short in the shift solenoid
valve SL1 circuit, the ECM determines there is a malfunction (See page DI-985).
MONITOR STRATEGY
Related DTCs P0748 Shift solenoid valve SL1/Range check
Required sensors/Components Shift solenoid valve SL1
Frequency of operation Continuous
Duration 1 sec.
MIL operation Immediate
Sequence of operation None
TYPICAL ENABLING CONDITIONS
Specification
Item
It
Minimum Maximum
The monitor will run whenever this DTC is
See page DI-963
not present.
Battery voltage 10 V or more -
CPU commanded duty - Less than 75%
Ignition switch ON
Switch OFF
DI-1021
DIAGNOSTICS - AUTOMATIC TRANSMISSION (A750E for 1GR-FE)
TYPICAL MALFUNCTION THRESHOLDS
Detection criteria Threshold
Output signal duty 100%
COMPONENT OPERATING RANGE
Parameter Standard value
Output signal duty Less than 100%
WIRING DIAGRAM
E1 Electronically Controlled
Transmission Solenoid ECM
+B
SL1 19
R R-W CPU
E6
SL1+ 12
SL1+
18 SL1-
L GR
E6
SL1- 4
D14168
DI-1022
DIAGNOSTICS - AUTOMATIC TRANSMISSION (A750E for 1GR-FE)
INSPECTION PROCEDURE
HINT:
S The shift solenoid valve SL1 is turned on/off normally when the shift lever is in the D position:
ECM command gearshift 1st 2nd 3rd 4th 5th
Shift solenoid valve SL1 OFF OFF OFF OFF ON
1 Inspect transmission wire.
Transmission Wire Side: PREPARATION:
(Connector Front View): Disconnect the transmission wire connector.
CHECK:
SL1- Measure the resistance according to the value(s) in the table
E1 below.
8 7 6 5 4 3 2 1
OK:
15 14 13 12 11 10 9
Specified Condition
Tester Connection
20_C (68_F)
SL1+ D11994
12 (SL1+) - 4 (SL1-) 5.0 to 5.6
CHECK:
Measure the resistance according to the value(s) in the table
below.
OK:
Tester Connection Specified Condition
12 (SL1+) - Body ground 10 k or higher
4 (SL1-) - Body ground
NG Go to step 3.
OK
DI-1023
DIAGNOSTICS - AUTOMATIC TRANSMISSION (A750E for 1GR-FE)
2 Check harness and connector (Transmission wire - ECM)
ECM: PREPARATION:
E7 E6 E5 E4 E3 (a) Connect the transmission wire connector.
(b) Disconnect the ECM connector.
CHECK:
Measure the resistance according to the value(s) in the table
below.
OK:
SL1+
Specified Condition
SL1- Tester Connection
D14166
20_C (68_F)
E6 - 19 (SL1+) - E6 - 18 (SL1-) 5.0 to 5.6
CHECK:
Measure the resistance according to the value(s) in the table
below.
OK:
Tester Connection Specified Condition
E6 - 19 (SL1+) - Body ground 10 k or higher
E6 - 18 (SL1-) - Body ground
NG Repair or replace the harness or connector
(See page IN-30).
OK
Replace the ECM (See page SF-66).
DI-1024
DIAGNOSTICS - AUTOMATIC TRANSMISSION (A750E for 1GR-FE)
3 Inspect shift solenoid valve SL1.
Shift Solenoid Valve SL1: PREPARATION:
Remove the shift solenoid valve SL1 (See page AT-12).
1 2
CHECK:
Measure the resistance according to the value(s) in the table
below.
OK:
Specified Condition
Tester Connection
20_C (68_F)
1-2 5.0 to 5.6
CHECK:
1 2 Connect the positive (+) lead with a 21 W bulb to terminal 2 and
the negative (-) lead to terminal 1 of the solenoid valve connec-
tor, then check the movement of the valve.
OK:
The solenoid makes an operating sound.
(-) (+)
D12795
NG Replace the shift solenoid valve SL1
(See page AT-12).
OK
Repair or replace the transmission wire
(See page AT-9).