DESCRIPTION
Shift 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 TCM adjusts the duty ratio* of 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.
Tech Tips
*: The duty ratio is the ratio of the electrical current on time (A) to the total of the electrical current on and off time (A + B).
Duty Ratio (%) = (A / (A + B)) x 100
| DTC Code | DTC Detection Condition | Trouble Area |
|---|---|---|
| P2714 | The TCM detects a malfunction in shift solenoid valve SLT (ON side) according to the difference in the speed between the turbine and output shaft, and also by the ATF pressure. (2-trip detection logic) |
|
MONITOR DESCRIPTION
The TCM calculates the amount of heat absorbed by the friction material based on the difference in revolution speed (clutch slippage) between the turbine and output shaft. The TCM turns on the MIL and stores this DTC when the amount of heat absorption exceeds the specified value.
When shift solenoid valve SLT remains on, the line pressure goes down and clutch engagement force decreases.
Note
If driving continues under these conditions, clutches will burn out and the vehicle will no longer be drivable.
INSPECTION PROCEDURE
PROCEDURE
CHECK DTC OUTPUT (IN ADDITION TO DTC P2714)
Connect the intelligent tester to the DLC3.
Turn the ignition switch to ON.
Turn the intelligent tester on.
Enter the following menus: Powertrain / ECT / DTC.
Read the DTCs using the intelligent tester.
| Result | Proceed to |
|---|---|
| P2714 and other DTCs are output | A |
| Only P2714 is output | B |
Tech Tips
If shift solenoid valve SLT is stuck on, DTCs for several shift solenoid valves including the malfunctioning shift solenoid valve will be stored.
| B |
|
INSPECT SHIFT SOLENOID VALVE SLT Click here |
| A |
|
PERFORM ACTIVE TEST USING INTELLIGENT TESTER (SHIFT SOLENOID VALVE SLT)
Note
Perform the test while the ATF temperature is 50 to 80°C (122 to 176°F).
Be careful to prevent the hose of SST from interfering with the exhaust pipe.
This check must be conducted after checking and confirming that the engine is normal.
Perform the test with the A/C off.
Tech Tips
Using the intelligent tester 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.
Remove the test plug from the transaxle case and connect SST.
Connect the intelligent tester to the DLC3.
Start the engine and warm it up.
Measure the line pressure when the engine is idling.
Turn the intelligent tester on.
Enter the following menus: Powertrain / ECT / Active Test.
According to the display on the tester, perform the Active Test.
Measure the line pressure with SST.
| Tester Display | Test Part | Control Range | Diagnostic Note |
|---|---|---|---|
| Activate the Solenoid (SLT)* | Operate shift solenoid valve SLT and raise line pressure | ON or OFF Tech Tips ON: No action (normal operation) OFF: Line pressure up (When Active Test "Activate the Solenoid (SLT)" is performed, TCM commands shift solenoid valve SLT to turn off). |
[Vehicle Condition]
|
Tech Tips
*: The "Activate the Solenoid (SLT)" Active Test is performed to confirm that the line pressure changes. The line pressure changes are confirmed using the same SST that is used for the Hydraulic Test Click here.
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. |
| NG |
|
INSPECT SHIFT SOLENOID VALVE SLT Click here |
| OK |
|
PERFORM ACTIVE TEST USING INTELLIGENT TESTER (RUNNING TEST)
Note
This test should always be performed with at least 2 people.
Warm up the engine.
Turn the ignition switch off.
Connect the intelligent tester to the DLC3.
Turn the ignition switch to ON.
Turn the intelligent tester on.
Enter the following menus: Powertrain / ECT / Active Test.
According to the display on the intelligent tester, perform the Active Test.
Tech Tips
Comparing the gear commanded by the Active Test with the actual gear enables confirmation of the problem Click here.
| Tester Display | Test Part | Control Range | Diagnostic Note |
|---|---|---|---|
| Control the Shift Position | Operate the shift solenoid valves and set each shift position |
|
Can be used to check the operation of the shift solenoid valves. A 10-second interval is required between gear changes. Do not down-shift at high speeds. Doing so will damage the automatic transaxle. [Vehicle Condition]
|
Note
This test can be conducted when the vehicle is stopped.
When shifting gears using the Active Test function, do not operate the accelerator pedal for 2 seconds before and after shifting gears.
Tech Tips
The gear commanded by the TCM is shown in the Data List / Shift Status display on the intelligent tester.
Check the vehicle speed and gear when the engine speed is 1000 rpm.
Tech Tips
Because the torque converter clutch has not engaged, it may be difficult to obtain the speeds specified in 4th, 5th and 6th gear, however a difference of speed should still be evident following each gear change.
| 1st | 2nd | 3rd | 4th | 5th | 6th |
|---|---|---|---|---|---|
| 8 to 12 km/h (5 to 7.5 mph) | 15 to 19 km/h (9.3 to 11.8 mph) | 21 to 25 km/h (13.0 to 15.5 mph) | 31 to 35 km/h (19.3 to 21.7 mph) | 44 to 48 km/h (27.3 to 29.8 mph) | 52 to 56 km/h (32.3 to 34.8 mph) |
Compare the TCM commanded gear and the actual gear.
| Result | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
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Tech Tips
*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.
| B |
|
GO TO DTC P0776 Click here |
| C |
|
GO TO DTC P0796 Click here |
| D |
|
GO TO DTC P2808 Click here |
| E |
|
INSPECT SHIFT SOLENOID VALVE SLT Click here |
| A |
|
GO TO DTC P0746 Click here
INSPECT SHIFT SOLENOID VALVE SLT
| *a | Component without harness connected (Shift Solenoid Valve SLT) |
Remove shift solenoid valve SLT.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | ||||||
|---|---|---|---|---|---|---|
|
Apply 12 V battery voltage to the shift solenoid valve and check that the valve moves and makes an operating noise.
| OK | ||||
|---|---|---|---|---|
|
| NG |
|
REPLACE SHIFT SOLENOID VALVE SLT Click here |
| OK |
|
INSPECT TRANSMISSION VALVE BODY ASSEMBLY
Check the transmission valve body assembly Click here.
| OK |
|---|
| There are no foreign objects on any valve. |
| NG |
|
REPAIR OR REPLACE TRANSMISSION VALVE BODY ASSEMBLY Click here |
| OK |
|
REPAIR OR REPLACE AUTOMATIC TRANSAXLE ASSEMBLY Click here
INSPECT SHIFT SOLENOID VALVE SLT
| *a | Component without harness connected (Shift Solenoid Valve SLT) |
Remove shift solenoid valve SLT.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | ||||||
|---|---|---|---|---|---|---|
|
Apply 12 V battery voltage to the shift solenoid valve and check that the valve moves and makes an operating noise.
| OK | ||||
|---|---|---|---|---|
|
| NG |
|
REPLACE SHIFT SOLENOID VALVE SLT Click here |
| OK |
|
INSPECT TRANSMISSION VALVE BODY ASSEMBLY
Check the transmission valve body assembly Click here.
| OK |
|---|
| There are no foreign objects on any valve. |
| NG |
|
REPAIR OR REPLACE TRANSMISSION VALVE BODY ASSEMBLY Click here |
| OK |
|
REPAIR OR REPLACE AUTOMATIC TRANSAXLE ASSEMBLY Click here
INSPECT SHIFT SOLENOID VALVE SLT
| *a | Component without harness connected (Shift Solenoid Valve SLT) |
Remove shift solenoid valve SLT.
Measure the resistance according to the value(s) in the table below.
| Standard Resistance | ||||||
|---|---|---|---|---|---|---|
|
Apply 12 V battery voltage to the shift solenoid valve and check that the valve moves and makes an operating noise.
| OK | ||||
|---|---|---|---|---|
|
| NG |
|
REPLACE SHIFT SOLENOID VALVE SLT Click here |
| OK |
|
INSPECT TRANSMISSION VALVE BODY ASSEMBLY
Check the transmission valve body assembly Click here.
| OK |
|---|
| There are no foreign objects on any valve. |
| NG |
|
REPAIR OR REPLACE TRANSMISSION VALVE BODY ASSEMBLY Click here |
| OK |
|
REPAIR OR REPLACE AUTOMATIC TRANSAXLE ASSEMBLY Click here