AA80E Automatic Transmission: Automatic Transmission System

AA80E AUTOMATIC TRANSMISSION: AUTOMATIC TRANSMISSION SYSTEM: P0741: Torque Converter Clutch Solenoid Performance (Shift Solenoid Valve SL)

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

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

SYSTEM DESCRIPTION

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






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 shift solenoid SL is turned on, it applies pressure to the lock-up 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 to be 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





- When either condition below is met: Condition (1) or (2)

Condition (1)

When one of the following conditions is met: Condition (a), (b), (c), (d), (e), (f), (g) or (h)

Condition (a)





Condition (b)





Condition (c)





Condition (d)





Condition (e)





Condition (f)





Condition (g)





Condition (h)






OFF malfunction





TYPICAL MALFUNCTION THRESHOLDS

OFF malfunction





INSPECTION PROCEDURE

PROCEDURE

1. CHECK DTC OUTPUT (IN ADDITION TO DTC P0741 and P2757)
(a) Connect the Techstream to the DLC3.
(b) Turn the engine switch on (IG).
(c) Turn the Techstream on.
(d) Enter the following menus: Powertrain / ECT / Trouble Codes.
(e) Read the DTCs using the Techstream.
Result:





HINT: If a solenoid related or oil pressure switch related DTC is output, troubleshoot those DTCs first.

B -- GO TO DTC CHART
A -- Continue to next step.

2. INSPECT SHIFT SOLENOID VALVE SL AND SHIFT SOLENOID VALVE SLU




(a) Check the shift solenoid valve SL.
(1) Remove the shift solenoid valve SL Disassembly.
(2) Measure the resistance of the shift solenoid valve.
Standard resistance:






(3) Connect the battery's positive (+) lead to the terminal of the solenoid valve connector, and the negative (-) lead to the solenoid body. Then check that the valve moves and makes an operating sound.
OK:
Valve moves and makes operating sound.




(b) Check the shift solenoid valve SLU.
(1) Remove the shift solenoid valve SLU Disassembly.
(2) Measure the resistance of the shift solenoid valve.
Standard resistance:






(3) Connect the battery's positive (+) lead with a 21 W bulb to terminal 2 and the negative (-) lead to terminal 1 of the solenoid valve connector. Then check that the valve moves and makes an operating sound.
OK:
Valve moves and makes operating sound.
Result:






C -- REPLACE SHIFT SOLENOID VALVE SLU
B -- REPLACE SHIFT SOLENOID VALVE SL
A -- Continue to next step.

3. INSPECT TRANSMISSION VALVE BODY ASSEMBLY
(a) Check the transmission valve body assembly Disassembly.
OK:
There are no foreign objects on any valve.
NG -- REPAIR OR REPLACE TRANSMISSION VALVE BODY ASSEMBLY
OK -- Continue to next step.

4. INSPECT TORQUE CONVERTER CLUTCH ASSEMBLY
(a) Check the torque converter clutch assembly AA80E Automatic Transmission.
OK:
The torque converter clutch operates normally.
NG -- REPLACE TORQUE CONVERTER CLUTCH ASSEMBLY
OK -- REPAIR OR REPLACE AUTOMATIC TRANSMISSION ASSEMBLY