Toyota Tacoma (2015-2018) Service Manual: Pressure Control Solenoid "D" Performance (Shift Solenoid Valve SLT) (P2714)

Toyota Tacoma (2015-2018) Service Manual / Ac60e Automatic Transmission / Transaxle / Automatic Transmission System(for 2tr-fe) / Pressure Control Solenoid "D" Performance (Shift Solenoid Valve SLT) (P2714)

SYSTEM DESCRIPTION

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

DTC No.	DTC Detection Condition	Trouble Area
P2714	The ECM detects a malfunction in the shift solenoid valve SLT (ON side) according to the difference in the speed between the turbine and the output shaft, and also by the ATF pressure. (2 trip detection logic)	Shift solenoid valve SLT remains open Shift solenoid valve SL1, SL2, SL3 or SL4 remains open or closed Transmission valve body assembly is blocked Automatic transmission assembly (clutch, brake or gear, etc.)

MONITOR DESCRIPTION

The ECM calculates the amount of clutch slip based on the input turbine speed, output shaft speed, and gear ratio. If the amount of clutch slip exceeds a specified level, the ECM will set this DTC and illuminate the MIL.

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

NOTICE:

If the vehicle continues to be driven under these conditions, the clutch will burn up and the vehicle will no longer be drivable.

MONITOR STRATEGY

Related DTCs	P2714: Shift solenoid valve SLT/ON malfunction
Required sensors/Components	Shift solenoid valve SLT
Frequency of operation	Continuous
Duration	ON malfunction: 0.5 sec.
MIL operation	2 driving cycles
Sequence of operation	None

TYPICAL ENABLING CONDITIONS

ON malfunction:

The monitor will run whenever the following DTCs are not stored	P0712, P0713 (TFT (ATF temperature) sensor circuit) P0115, P0117, P0118 (ECT (Engine coolant temperature) sensor circuit) P0717, P07BF, P07C0 (Turbine speed sensor circuit) P0722, P077C, P077D (Output speed sensor circuit) P0335 (Crankshaft position sensor circuit (This condition applies only if using fail-safe)) P0748 (Shift solenoid valve SL1 circuit) P0778 (Shift solenoid valve SL2 circuit) P0798 (Shift solenoid valve SL3 circuit) P2810 (Shift solenoid valve SL4 circuit) P2716 (Shift solenoid valve SLT circuit) P0327, P0328, P0332, P0333 (KCS (Knock control sensor) circuit) P0120, P0121, P0122, P0123, P0220, P0222, P0223, P0604, P0606, P060A, P060B, P060D, P060E, P0657, P1607, P2102, P2103, P2111, P2112, P2118, P2119, P2135 (ETCS (Electronic throttle control system)) U0100 (CAN communication system)
TFT (ATF temperature) sensor circuit	Not circuit malfunction
ECT (Engine coolant temperature) sensor circuit	Not circuit malfunction
Turbine speed sensor circuit	Not circuit malfunction
Output speed sensor circuit	Not circuit malfunction
Shift solenoid valve SL1 circuit	Not circuit malfunction
Shift solenoid valve SL2 circuit	Not circuit malfunction
Shift solenoid valve SL3 circuit	Not circuit malfunction
Shift solenoid valve SL4 circuit	Not circuit malfunction
Shift solenoid valve SLT circuit	Not circuit malfunction
KCS (Knock control sensor) circuit	Not circuit malfunction
ETCS (Electronic throttle control system)	Not system down
CAN communication system	Not system down
Transmission range	"D"
Duration time from shifting "N" to "D"	4 sec. or more
TFT (ATF temperature)	-10°C (14°F) or higher
Engine	Running

TYPICAL MALFUNCTION THRESHOLDS

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

ON malfunction (A):

Summation of clutch heat generations

Specified value

ON malfunction (B):

Shift solenoid valve SL1 ON malfunction

Detected

ON malfunction (C):

Shift solenoid valve SL1 OFF malfunction

Detected

ON malfunction (D):

Shift solenoid valve SL2 OFF malfunction

Detected

ON malfunction (E):

Shift solenoid valve SL3 OFF malfunction

Detected

ON malfunction (F):

Shift solenoid valve SL4 ON malfunction

Detected

ON malfunction (G):

Shift solenoid valve SL4 OFF malfunction

Detected

CAUTION / NOTICE / HINT

NOTICE:

Perform the universal trip to clear permanent DTCs (See page ).
Perform registration and/or initialization when parts related to the automatic transmission are replaced (See page ).

HINT:

After the repair, clear the DTCs and perform the following procedure to check that DTCs are not output.

Perform the D Position Shift Test in Road Test (See page ).*1
Turn the ignition switch off.
Perform step (*1) again.
Check for DTCs again (See page ).

PROCEDURE

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

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

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

(e) Read the DTCs using the Techstream.

Result

Result	Proceed to
Only DTC P2714 is output	A
P2714 and other DTCs are output	B

HINT:

If a solenoid is stuck on, DTCs for several solenoids including the malfunctioning solenoid will be detected.

GO TO STEP 4

2.	PERFORM ACTIVE TEST USING TECHSTREAM (ACTIVATE THE SOLENOID (SLT))

NOTICE:

Perform the test while the ATF (Automatic Transmission Fluid) temperature is between 50 and 80°C (122 and 176°F).
Be careful to prevent the hose of SST from interfering with the exhaust pipe.
This check must be conducted after checking and adjusting the engine.
Perform the test with the air conditioning 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.

SST: 09993-19015

09993-00010

09993-00040

(d) Lower the vehicle.

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

(f) Connect the Techstream to the DLC3.

(g) Start the engine.

(h) Warm up the ATF (Automatic Transmission Fluid).

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

(j) Turn the Techstream on.

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

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

(m) Measure the line pressure with SST.

Engine and ECT

Tester Display	Test Part	Control Range	Diagnostic Note
Activate the Solenoid (SLT)*	Operates shift solenoid valve SLT to raise the line pressure.	ON/OFF HINT: ON: No action (normal operation) OFF: Line pressure up (When the Active Test of "Activate the Solenoid (SLT)" is performed, the ECM commands the shift solenoid valve SLT to turn off).	[Vehicle Condition] Vehicle Stopped Engine idling

Tester Display

Test Part

Control Range

Diagnostic Note

Activate the Solenoid (SLT)*

Operates shift solenoid valve SLT to raise the line pressure.

ON/OFF

HINT:

ON: No action (normal operation)

OFF: Line pressure up (When the Active Test of "Activate the Solenoid (SLT)" is performed, the ECM commands the shift solenoid valve SLT to turn off).

[Vehicle Condition]

Vehicle Stopped
Engine idling

*: The "Activate the solenoid (SLT)" Active Test is performed to allow confirmation that the line pressure changes. The line pressure changes are confirmed using the same SST that is used for the Hydraulic Test (See page HINT: ).

HINT:

Note that the pressure readings for the Active Test and Hydraulic Test are different.

OK:

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

GO TO STEP 4

3.	PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE SHIFT POSITION)

NOTICE:

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

(a) Warm up the engine.

(b) Turn the ignition switch off.

(d) Turn the ignition switch to ON.

(e) Turn the Techstream on.

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

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

HINT:

Comparing the gear commanded by the Active Test with the actual gear enables confirmation of the problem (See page Engine and ECT ).

Engine and ECT

Tester Display	Test Part	Control Range	Diagnostic Note
Control the Shift Position	Operates the shift solenoid valves to allow gears to be selected manually.	Press "→" button: Up-shift occurs Press "←" button: Down-shift occurs	Can be used to check the operation of the shift solenoid valves. Up-shifts and down-shifts should be performed consecutively. A 10 second interval is required between gear changes. Do not down-shift at high speeds. Doing so will damage the automatic transmission. [Vehicle Condition] 50 km/h (31 mph) or less

Tester Display

Test Part

Control Range

Diagnostic Note

Control the Shift Position

Operates the shift solenoid valves to allow gears to be selected manually.

Press "→" button: Up-shift occurs
Press "←" button: Down-shift occurs

Can be used to check the operation of the shift solenoid valves.

Up-shifts and down-shifts should be performed consecutively. A 10 second interval is required between gear changes.

Do not down-shift at high speeds. Doing so will damage the automatic transmission.

[Vehicle Condition]

50 km/h (31 mph) or less

HINT:

This test can be conducted when the vehicle speed is 50 km/h (31 mph) or less.
The 4th to 5th and 5th to 6th up-shift must be performed with the accelerator pedal released.
The 6th to 5th and 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 gear commanded by the ECM is shown in the Data List / Shift Status display on the Techstream.

(h) Compare the ECM commanded gear and the actual gear.

Result

Actual Gear during Malfunction		ECM Commanded Gear						Proceed to
Actual Gear during Malfunction		1st	2nd	3rd	4th	5th	6th	Proceed to
Shift solenoid valve SL1	Stuck ON	1st	2nd	3rd	4th	4th	4th	A
Shift solenoid valve SL1	Stuck OFF	N*1	N*1	N*1	N*1	5th	6th	A
Shift solenoid valve SL2	Stuck ON	4th	4th	4th	4th	5th	6th	B
Shift solenoid valve SL2	Stuck OFF	1st	2nd	3rd	1st	N*1	N*1	B
Shift solenoid valve SL3	Stuck ON	2nd	2nd	3rd	4th	5th	6th	C
Shift solenoid valve SL3	Stuck OFF	1st	1st	3rd	4th	5th	N*1	C
Shift solenoid valve SL4	Stuck ON	3rd	3rd	3rd	4th	5th	5th	D
Shift solenoid valve SL4	Stuck OFF	1st	2nd	1st	4th	N*1	6th	D
Shift solenoid valve SLT	Stuck ON	N*2	N*2	N*2	N*2	N*2	N*2	E
Shift solenoid valve SLT	Stuck OFF*3	1st	2nd	3rd	4th	5th	6th	E

HINT:

*1: Neutral
*2: If shift solenoid valve SLT is stuck on, the line pressure will be low. Therefore, the amount of torque that can be transmitted by each gear is lower than the normal limit. When the engine power exceeds this lowered limit, the engine speed will increase freely.
*3: When shift solenoid valve SLT is stuck off, gear shifting is normal.

GO TO DTC CHART (RELATED SHIFT SOLENOID VALVE SL1 PERFORMANCE DTC P0746)

GO TO DTC CHART (RELATED SHIFT SOLENOID VALVE SL2 PERFORMANCE DTC P0776)

GO TO DTC CHART (RELATED SHIFT SOLENOID VALVE SL3 PERFORMANCE DTC P0796)

GO TO DTC CHART (RELATED SHIFT SOLENOID VALVE SL4 PERFORMANCE DTC P2808)

4.	INSPECT SHIFT SOLENOID VALVE SLT

(a) Remove shift solenoid valve SLT (See page ).

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
1 - 2	20°C (68°F)	5.0 to 5.6 Ω

OK:

Measurement Condition	Specified Condition
Battery positive (+) with a 21 W bulb → Terminal 1 Battery negative (-) → Terminal 2	Valve moves and makes an operating noise

Text in Illustration

*1	Shift Solenoid Valve SLT

REPLACE SHIFT SOLENOID VALVE SLT

5.	INSPECT TRANSMISSION VALVE BODY ASSEMBLY

(a) Check the transmission valve body assembly (See page OK: ).

OK:

There is no foreign matter on each valve and they operate smoothly.

REPAIR OR REPLACE AUTOMATIC TRANSMISSION ASSEMBLY

REPAIR OR REPLACE TRANSMISSION VALVE BODY ASSEMBLY

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