A750E Automatic Transmission System

A750E AUTOMATIC TRANSMISSION: AUTOMATIC TRANSMISSION SYSTEM: P2714: Pressure Control Solenoid "D" Performance (Shift Solenoid Valve SLT)
P2714 - Pressure Control Solenoid "D" Performance (Shift Solenoid Valve SLT)

DESCRIPTION

The linear solenoid valve (SLT) controls the transmission line pressure for smooth transmission operation based on signals from the throttle position sensor and vehicle speed sensor. The ECM adjusts the duty ratio of the SLT solenoid valve to control hydraulic line pressure coming from the primary regulator valve. Appropriate line pressure assures smooth shifting with varying engine outputs.

MONITOR DESCRIPTION

The ECM calculates the amount of heat absorbed by the friction material based on the difference in revolution (clutch slippage) between the turbine and output shaft. The ECM turns on the MIL and outputs this DTC when the amount of heat absorption exceeds the specified value.

There are two reasons that make the revolution different.

- When the shift solenoid valve SLT remains on, oil pressure goes down and clutch engagement force decreases.

- When the shift solenoid valve remains on or off, the gear position commanded by the ECM and the actual gear position are not the same.

NOTICE:
If you continue driving under these conditions, the clutch will burn out and the vehicle will no longer be drivable.

MONITOR STRATEGY

TYPICAL ENABLING CONDITIONS

TYPICAL MALFUNCTION THRESHOLDS

- One of the following conditions is met: ON malfunction (A), (B), (C), (D), (E), (F) or (G)

ON malfunction (A)

ON malfunction (B)

ON malfunction (C)

ON malfunction (D)

ON malfunction (E)

ON malfunction (F)

ON malfunction (G)

INSPECTION PROCEDURE

NOTICE:
Perform the universal trip to clear permanent DTCs DTC Check / Clear.

PROCEDURE

1. CHECK OTHER DTCS OUTPUT (IN ADDITION TO DTCS P2714)

(a) Connect Techstream to the DLC3.

(b) Turn the ignition switch to ON

(c) Turn the Techstream on.

(d) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

(e) Read the DTCs using Techstream.

Result

HINT
If any other codes besides P2714 are output, perform troubleshooting for those DTCs first.

B -- GO TO DTC CHART Automatic Transmission System - A750E
A -- Continue to next step.

2. PERFORM ACTIVE TEST USING TECHSTREAM (SHIFT SOLENOID VALVE SLT)

NOTICE:
* Perform the test at the normal operating ATF temperature: 50 to 80°C (122 to 176°F).
* Be careful to prevent SST's hose from interfering with the exhaust pipe.
* Perform the test with the A/C OFF.

HINT
Using the Techstream to perform Active Tests 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 Tests early in troubleshooting is one way to save diagnostic time. Data List information can be displayed while performing Active Tests.

(a) Turn the ignition switch off.

(b) Lift the vehicle up.

(c) Remove the test plug on the transmission case center right side and connect SST.

SST : 09992-00095

09992-00231

09992-00271

(d) Lower the vehicle.

(e) Fully apply the parking brake and chock the 4 wheels.

(f) Connect Techstream to the DLC3.

(g) Start the engine and warm it up.

(h) Measure the line pressure when the engine is idling.

(i) Turn the Techstream on.

(j) Enter the following menus: Powertrain / Engine and ECT / Active Test.

(k) Follow the instructions on the Techstream and perform the Active Test.

(l) Measure the line pressure with SST.

Engine and ECT

HINT
*: Activate the Solenoid (SLT) in the Active Test is performed to check the line pressure changes by connecting SST to the automatic transmission, which is used in the Hydraulic Test Hydraulic Test as well. Please note that the pressure values in the Active Test and Hydraulic Test are different.

OK:

The line pressure changes as specified when performing the Active Test.

NG -- INSPECT SHIFT SOLENOID VALVE SLT
OK -- Continue to next step.

3. PERFORM ACTIVE TEST USING TECHSTREAM (RUNNING TEST)

NOTICE:
This test should always be performed with at least 2 people.

(a) Connect Techstream to the DLC3.

(b) Clear the DTC DTC Check / Clear.

(c) Enter the following menus: Powertrain / Engine and ECT / Active Test.

(d) Perform the Active Test using Techstream.

HINT
While driving, the shift position can be forcibly changed with Techstream.

Engine and ECT

HINT
* This test can be conducted when the vehicle speed is 50 km/h (31 mph) or less.
* The 4th to 5th up-shift must be performed with the accelerator pedal released.
* The 5th to 4th down-shift must be performed with the accelerator pedal released.
* Do not operate the accelerator pedal for at least 2 seconds after shifting and do not shift successively.
* The shift position commanded by the ECM is shown in the Data List display on Techstream.

(e) Compare the ECM gear shift command and the actual gear position.

HINT
* *1: Neutral
* *2: When shift solenoid S2 is stuck ON, the vehicle cannot drive in reverse.
* *3: When shift solenoid S2 is stuck OFF, the 4th to 5th upshift will have a large shift shock. Also, the 5th to 4th down-shift will have time lag.
* *4: Stuck ON condition can be determined by checking if shift shock has increased excessively.
* *5: When shift solenoid SR is stuck OFF, moving the shift lever from N to D will cause a large shift shock.
* Gear shift can be determined by paying attention to changes in rpm.

OK:

Gear position changes in accordance with the command.

E -- INSPECT SHIFT SOLENOID VALVE SLT

D -- INSPECT SHIFT SOLENOID VALVE SR

C -- INSPECT SHIFT SOLENOID VALVE SL2

B -- INSPECT SHIFT SOLENOID VALVE S2
A -- Continue to next step.

4. INSPECT SHIFT SOLENOID VALVE S1

(a) Remove the shift solenoid valve S1.