P0741

DTC P0741 Torque Converter Clutch Solenoid Performance (Shift Solenoid Valve SL)

DTC P2757 Torque Converter Clutch Pressure Control Solenoid Performance (Shift Solenoid Valve SLU)

DESCRIPTION
Based on the shift solenoid valve SL's ON or OFF signal, the TCM controls the fluid pressure to the lockup relay valve, and turns lock-up ON or OFF.

P0741/P2757:

MONITOR DESCRIPTION
Torque converter lock-up is controlled by the TCM based on the speed sensor (NT), engine rpm, engine load, engine temperature, vehicle speed, transmission fluid temperature, and gear selection. The TCM determines the lock-up status of the torque converter by comparing the engine rpm (NE) to the input turbine rpm (NT). The TCM calculates the actual transmission gear by comparing the input turbine rpm (NT) to the counter gear rpm (NC). When conditions are appropriate, the TCM requests "lock-up" by applying control voltage to the shift solenoid SL. When the SL is turned on, it applies pressure to the lockup relay valve and locks the torque converter clutch.

If the TCM detects no lock-up after lock-up has been requested, the TCM interprets this as a fault in the shift solenoid valve SL or SLU. The TCM will turn on the MIL and store the DTC.

HINT:
Example:
When the following condition is met, the system judges it as a malfunction.
There is a difference in rotation between the input side (engine speed) and output side (input turbine speed) of the torque converter when the TCM commands lock-up. (Engine speed is at least 70 rpm greater than the input turbine speed.)

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS

Part 1:

Part 2:

TYPICAL MALFUNCTION THRESHOLDS





INSPECTION PROCEDURE

Step 1(Part 1):

Steps 1(Part 2)-2:

Steps 3-4: