P0894

AB60F AUTOMATIC TRANSMISSION / TRANSAXLE: AUTOMATIC TRANSMISSION SYSTEM: P0894: Transmission Component Slipping

DTC P0894 - Transmission Component Slipping

DTC 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 the vehicle speed sensor. The ECM adjusts the duty ratio* of the SLT solenoid valve to control the hydraulic line pressure coming from the primary regulator valve. Appropriate line pressure assures smooth shifting with varying engine outputs.

HINT:
*: The duty ratio is the ratio of the current ON time (A) to the total of the current ON and OFF time (A + B).
Duty Ratio (%) = A / (A + B) x 100

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 illuminates the MIL and stores this DTC when the amount of heat absorption exceeds the specified value.
There are two causes of revolution difference.

- When the shift solenoid valve SLT remains ON, oil pressure decreases, which causes the clutch engagement force to decrease.
- 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.

NOTE: 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

All

HINT: *: Following conditions met

TYPICAL MALFUNCTION THRESHOLDS

[P0894: ON malfunction]
- When either condition below is met: ON malfunction (A) or (B)

ON Malfunction (A)

ON Malfunction (B)

[P2714: ON malfunction]
- One of the following conditions is met: ON malfunction (A), (B), (C), (D), (E), (F), (G) or (H)

ON Malfunction (A)

ON Malfunction (B)

ON Malfunction (C)

ON Malfunction (D)

ON Malfunction (E)

ON Malfunction (F)

ON Malfunction (G)

ON Malfunction (H)

INSPECTION PROCEDURE

PROCEDURE

1. CHECK DTC OUTPUT (IN ADDITION TO DTCS P0894 AND P2714)
(a) Connect the 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 the Techstream.

Result

HINT: If any other codes besides P0894 and P2714 are output, perform troubleshooting for those DTCs first.

B -- GO TO DTC CHART
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 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) Remove the test plug on the transmission case center right side and connect SST.
SST: 09992-00095
09992-00231
09992-00271
(b) Connect the Techstream to the DLC3.
(c) Start the engine and warm it up.
(d) Measure the line pressure with SST.
(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.
(h) Measure the line pressure.

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)

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) Connect the Techstream to the DLC3.

(b) Clear the DTC DTC Check / Clear.
(c) Enter the following menus: Powertrain / Engine and ECT / Active Test.
(d) According to the display on the Techstream, perform the Active Test.

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

Engine and ECT

HINT:
- This test can be conducted when the vehicle speed is 50 km/h (30 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 shift position commanded by the ECM is shown in the Data List display on the Techstream.
(e) Compare the ECM gear shift command and the actual gear position.

Result

HINT:
- *1: When shift solenoid S1 is stuck ON, the vehicle cannot drive in reverse.
- *2: Neutral
- *3: When shift solenoid S4 is stuck ON, gear shifting is normal.

E -- INSPECT SHIFT SOLENOID VALVE SLT
D -- INSPECT SHIFT SOLENOID VALVE S4
C -- INSPECT SHIFT SOLENOID VALVE S3
B -- INSPECT SHIFT SOLENOID VALVE S2
A -- Continue to next step.

4. INSPECT SHIFT SOLENOID VALVE S1

(a) Remove the shift solenoid valve S1.
(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

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

Result

B -- INSPECT TRANSMISSION VALVE BODY ASSEMBLY
A -- REPLACE SHIFT SOLENOID VALVE S1
5. INSPECT SHIFT SOLENOID VALVE S2

(a) Remove the shift solenoid valve S2.
(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

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

Result

B -- INSPECT TRANSMISSION VALVE BODY ASSEMBLY
A -- REPLACE SHIFT SOLENOID VALVE S2
6. INSPECT SHIFT SOLENOID VALVE S3

(a) Remove the shift solenoid valve S3.
(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

B -- INSPECT TRANSMISSION VALVE BODY ASSEMBLY
A -- REPLACE SHIFT SOLENOID VALVE S3
7. INSPECT SHIFT SOLENOID VALVE S4

(a) Remove the shift solenoid valve S4.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:

(a) Remove the shift solenoid valve SL2.
(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

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

Result

B -- INSPECT TRANSMISSION VALVE BODY ASSEMBLY
A -- REPLACE SHIFT SOLENOID VALVE SL2
9. INSPECT SHIFT SOLENOID VALVE SLT

(a) Remove the shift solenoid valve SLT.
(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

(c) Connect the battery 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 noise.
OK:
Valve moves and makes an operating noise.

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

10. INSPECT TRANSMISSION VALVE BODY ASSEMBLY
(a) Check the transmission valve body assembly.
OK:
There are no foreign objects on each valve.

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

11. INSPECT TORQUE CONVERTER CLUTCH ASSEMBLY
(a) Check the torque converter clutch assembly Testing and Inspection.
OK:
The torque converter clutch operates normally.

NG -- REPLACE TORQUE CONVERTER CLUTCH ASSEMBLY
OK -- REPAIR OR REPLACE AUTOMATIC TRANSMISSION ASSEMBLY