P2757

DTC P2757 Lock-up solenoid system (function/stuck OFF)
DTC P2758 Lock-up solenoid system (stuck ON)

Circuit description

The lock-up control solenoid (SLU) is controlled by the duty signal which is predetermined by the transmission control computer ASSY. Then, lock-up and flex lock-up control is performed.





Monitor description

The torque converter lock-up is controlled by TCM based on the transmission revolution sensor (NT, SP2), engine rpm, engine load, engine temperature, vehicle speed, transmission temperature, and selected gear. TCM compares engine rpm (NE) with input turbine rpm (NT) to determine the lock-up status of the torque converter. TCM compares input turbine rpm (NT) and output shaft rpm (SP2) to calculate the actual transmission gear. If the condition is appropriate, TCM applies control voltage to the shift solenoid SLU and requires "lock up". When SLU turns to ON, it applies pressure to the lock up relay valve to lock the torque converter clutch.
If TCM does not detect lock up after the lock up is requested or detects lock up even though it is not requested, TCM recognizes it as a malfunction of the shift solenoid valve SLU or lock up system performance. TCM turns on MIL and records the diagnostic codes.

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS
The following items are common to the all conditions below.





TYPICAL MALFUNCTION THRESHOLDS
P2757: Lock-up control solenoid (stuck OFF)





MAP A





P2758: Lock-up control solenoid (stuck ON)





MAP B





Circuit figure





Inspection steps