Toyota Celica 2005 Repair Manual page 923

DI−722
DTC P0746
DTC P0766
DTC P0776
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.
P0746 During normal driving, the gear required by the ECM does not
P0766 match the actual gear
P0776 (2−trip detection logic)
HINT:
Check the shift solenoid valve SL1 when DTC P0746 is output, check the shift solenoid valve SL2 when DTC
P0776 is output and check shift solenoid S4 when DTC P0766 is output.
MONITOR DESCRIPTION
P0746
The ECM commands gear shifts by turning the shift solenoid valves "ON/OFF". According to the input shaft
revolution, intermediate (counter) shaft revolution and output shaft revolution, the ECM detects the actual
gear position (1st, 2nd, 3rd or O/D gear position). When the gear position commanded by the ECM and the
actual gear position are not the same, the ECM illuminates the MIL.
Example:
When either condition (a) or (b) is met, the ECM detects a malfunction.
(a) The ECM commands the 1st gear, but the actual gear is 2nd.
(b) The ECM commands the 2nd gear, but the actual gear is 1st.
P0766, P0776
The ECM commands gear shifts by turning the shift solenoid valves "ON/OFF". According to the input shaft
revolution, intermediate (counter) shaft revolution and output shaft revolution, the ECM detects the actual
gear position (1st, 2nd, 3rd or O/D gear position). When the gear position commanded by the ECM and the
actual gear position are not the same, the ECM illuminates the MIL and stores the DTC.
2005 CELICA (RM1131U)
DIAGNOSTICS
Pressure Control Solenoid "A" Performance
(Shift Solenoid Valve SL1)
Shift Solenoid "D" Performance
(Shift Solenoid Valve S4)
Pressure Control Solenoid "B" Performance
(Shift Solenoid Valve SL2)
DTC Detecting Condition
− AUTOMATIC TRANSAXLE (U240E)
S Shift solenoid valve SL1/SL2/S4 is stuck open or closed
S Valve body is blocked up or stuck
922
Trouble Area
DI4ZZ−09