P2757

TX6A AUTOMATIC TRANSMISSION / TRANSAXLE: AUTOMATIC TRANSMISSION SYSTEM: P2757, P2758; Torque Converter Clutch Pressure Control Solenoid Performance (Shift Solenoid Valve SLU); 2013 MY FR-S [03/2012 -]
P2757 - Torque Converter Clutch Pressure Control Solenoid Performance (Shift Solenoid Valve SLU)
P2758 - Torque Converter Pressure Control Solenoid Circuit Stuck ON / Performance (SLU / DSU Solenoid)

SYSTEM DESCRIPTION

The shift solenoid valve SLU is controlled by the duty ratio as determined in advance by the TCM. In this way, it carries out lock-up and flex lock-up control.





MONITOR DESCRIPTION

Torque converter lock-up is controlled by the TCM based on the transmission revolution sensor (NT), transmission revolution sensor (SP2), engine rpm, engine load, engine temperature, vehicle speed, transmission 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 input turbine rpm (NT) to output shaft rpm (SP2). When conditions are appropriate, the TCM requests "lock-up" by applying control voltage to the shift solenoid valve SLU. When the SLU is turned on, it applies pressure to the lock-up relay valve and locks the torque converter assembly.

If the TCM detects no lock-up after lock-up has been requested or if it detects lock-up when it is not requested, the TCM interprets this as a fault in the shift solenoid valve SLU or lock-up system performance.

The TCM will turn on the MIL and store the DTC.

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS

The following items are common to all conditions below.





TYPICAL MALFUNCTION THRESHOLDS

P2757: Lock up Control Solenoid (OFF Stuck)

*





MAP A





P2758: Lock up Control Solenoid (ON Stuck)

*





MAP B





WIRING DIAGRAM





INSPECTION PROCEDURE

NOTICE:
Perform the universal trip to clear permanent DTCs Reading and Clearing Diagnostic Trouble Codes.

1. ACTIVE TEST

HINT
Using the Techstream to perform Active Test allows relays, VSVs, actuators and other items to be operated without removing any parts. This non-intrusive functional inspection can be very useful because intermittent operation may be discovered before parts or wiring is disturbed. Performing Active Test early in troubleshooting is one way to save diagnostic time. Data List information can be displayed while performing Active Test.

(a) Warm up the engine.

(b) Turn the ignition switch off.

(c) Connect the Techstream to the DLC3.

(d) Turn the ignition switch to ON.

(e) Turn the Techstream on.

(f) Enter the following menus: Powertrain / ECT / Data List.

(g) According to the display on the Techstream, perform the "Active Test".





HINT
* This test can be conducted when the vehicle speed is 50 km/h (30 mph) or more.
* This test can be conducted with the 5th or 6th gear.

(h) Lightly depress the accelerator pedal and check that the engine speed does not change abruptly.





HINT
* When changing the accelerator pedal opening angle while driving, if the engine speed does not change, lock-up is on.
* Slowly release, but not fully, the accelerator pedal in order to decelerate. (Fully releasing the pedal will close the throttle valve and lock-up may be turned off automatically.)

PROCEDURE

1. CHECK OTHER DTCS OUTPUT

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON and push the Techstream main switch ON.

(c) Read the DTCs using the Techstream Reading and Clearing Diagnostic Trouble Codes.

Result:





B -- GO TO DTC CHART TX6A Automatic Transmission
A -- Continue to next step.

2. INSPECT SHIFT SOLENOID VALVE SLU (TRANSMISSION VALVE BODY ASSEMBLY)

(a) Remove the transmission valve body assembly Removal.

(b) Measure the resistance according to the value(s) in the table below.









Standard Resistance:





(c) Connect the positive (+) lead with a 21 W bulb to terminal 2 and the negative (-) lead to terminal 1 of the shift solenoid valve SLU connector, then check the movement of the valve.

OK:

The solenoid makes an operating sound.

NG -- REPLACE TRANSMISSION VALVE BODY ASSEMBLY Removal
OK -- Continue to next step.

3. INSPECT TRANSMISSION VALVE BODY ASSEMBLY

(a) Perform inspection of the transmission valve body assembly Testing and Inspection.

OK:

There are no foreign objects on each valve.

NG -- REPAIR OR REPLACE TRANSMISSION VALVE BODY ASSEMBLY Removal
OK -- Continue to next step.

4. INSPECT TORQUE CONVERTER ASSEMBLY

(a) Check the torque converter assembly Testing and Inspection.

OK:

The Torque converter assembly operates normally.

NG -- REPLACE TORQUE CONVERTER ASSEMBLY Removal

OK -- REPLACE AUTOMATIC TRANSMISSION ASSEMBLY Removal