Toyota Celica 2005 Repair Manual page 1010

DTC P0743
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.
Either (a) or (b) is detected for 1 time.
(2−trip detection logic)
(a) Solenoid resistance is 8 Ω or less when solenoid is ener-
P0743
gized.
(b) Solenoid resistance is 100 kΩ or more when solenoid is not
energized.
MONITOR DESCRIPTION
Based on the signals from the Throttle Position Sensor, the Airflow Meter and the Crankshaft Position Sen-
sor, the ECM sends a signal to the SL Solenoid Valve to regulate the hydraulic pressure and provide smooth-
er gearshifts. The shift−solenoid valve SL responds to commands from the ECM. The valve controls the
look−up relay valve to perform the torque−converter lock−up function. If the ECM detects an open or short
circuit for shift−solenoid SL, it will illuminate the MIL and store the DTC.
MONITOR STRATEGY
Related DTCs
Required sensors/Components
Frequency of operation
Duration
MIL operation
Sequence of operation
TYPICAL ENABLING CONDITIONS
Item
The monitor will run whenever this DTC is
not present.
The typical enabling condition is not avail-
able.
2005 CELICA (RM1131U)
DIAGNOSTICS
Torque Converter Clutch Circuit Electrical
(Shift Solenoid Valve SL)
DTC Detecting Condition
P0743
Shift solenoid valve SL
Continuous
0.032 sec.
2 driving cycles
None
Minimum
− AUTOMATIC TRANSAXLE (U341E)
S Open or short in shift solenoid valve SL circuit
S Shift solenoid valve SL
S ECM
Shift solenoid valve SL/Range check (Low resistance)
Shift solenoid valve SL/Range check (High resistance)
Specification
See page DI−758
−
1009
Trouble Area
Maximum
DI−809
DIAJD−03