P0756
A750F AUTOMATIC TRANSMISSION: AUTOMATIC TRANSMISSION SYSTEM: P0756: Shift Solenoid "B" Performance (Shift Solenoid Valve S2)
DTC P0756 - Shift Solenoid "B" Performance (Shift Solenoid Valve S2)
DESCRIPTION
The ECM uses signals from the output shaft speed sensor and input speed sensor to detect the actual gear position (1st, 2nd, 3rd, 4th or 5th gear).
Then the ECM compares the actual gear with the shift schedule in the ECM memory to detect mechanical problems of the shift solenoid valves, valve body or automatic transmission (clutch, brake or gear, etc.).
HINT: Gear positions in the event of a solenoid valve mechanical problem:
N*: Neutral
MONITOR DESCRIPTION
This DTC indicates "stuck ON malfunction" or "stuck OFF malfunction" of the shift solenoid valve S2. The ECM controls the gearshifts by turning the shift solenoid valves "ON/OFF". When the gear position directed by the ECM and the actual gear position do not match, the ECM illuminates the MIL and stores the DTC.
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
The following conditions are common to all OFF malfunctions (A), (B), (C) and (D) and ON malfunctions (A), (B), (C) and (D).
*1: Following conditions are met
OFF malfunction (A)
OFF malfunction (B)
OFF malfunction (C)
OFF malfunction (D)
ON malfunction (A)
ON malfunction (B)
ON malfunction (C)
ON malfunction (D)
TYPICAL MALFUNCTION THRESHOLDS
[OFF malfunction]
All of the following conditions are met: OFF malfunctions (A), (B), (C) and (D)
2 detections are necessary in 1 driving cycle.
1st detection; temporary flag ON
2nd detection; pending fault code ON
OFF malfunction (A)
OFF malfunction (B)
OFF malfunction (C)
OFF malfunction (D)
[ON malfunction]
ON malfunction (A) or (B) and ON malfunction (C) or (D) are met:
ON malfunction (A)
ON malfunction (B)
ON malfunction (C)
ON malfunction (D)
INSPECTION PROCEDURE
HINT: Performing the Active Test using a Techstream allows components, such as the relay, VSV, and actuator, to be operated without removing any parts. Performing the Active Test as a first step of troubleshooting is one method of shortening labor time.
It is possible to display the Data List during the Active Test.
1. Warm up the engine.
2. Turn the ignition switch off.
3. Connect the Techstream to the DLC3.
4. Turn the ignition switch to ON.
5. Turn the Techstream on.
6. Enter the following menus: Powertrain / Engine and ECT / Active Test.
7. According to the display on the Techstream, perform the Active Test.
HINT: While driving, the shift position can be changed with the Techstream.
Comparing the shift position directed by the Active Test with the actual shift position enables the problem to be confirmed Fail-Safe Chart.
HINT:
- This test can be conducted when the vehicle speed is 30 mph (50 km/h) or less.
- The 4th to 5th up-shifting must be performed with the accelerator pedal released.
- The 5th to 4th down-shifting 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 directed by the ECM is shown in the Data List / Shift Status display on the Techstream.
- The shift solenoid valve S2 is turned on/off normally when the shift lever is in the D position:
PROCEDURE
1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0756)
(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 codes besides "P0756" 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 (Automatic Transmission Fluid) 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: Performing a Techstream Active Test allows relay, VSV, actuator and other items to be operated without removing any parts. Performing the Active Test early in troubleshooting is one way to save time.
The Data List can be displayed during the Active Test.
(a) Remove the test plug on the transmission case center right side and connect SST.
SST: 09992-00095
09992-00231
09992-00271
(b) Connect a 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 with SST.
*: Active 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.
NG -- REPLACE SHIFT SOLENOID VALVE SLT
OK -- Continue to next step.
3. INSPECT SHIFT SOLENOID VALVE S2
(a) Remove the shift solenoid valve S2.
(b) Measure the resistance.
Standard resistance:
(c) Connect the positive (+) lead to the terminal of the solenoid connector, and the negative (-) lead to the solenoid body.
OK:
The solenoid makes operating sounds.
NG -- REPLACE SHIFT SOLENOID VALVE S2
OK -- Continue to next step.
4. INSPECT TRANSMISSION VALVE BODY ASSEMBLY (See chapter 2 in the problem symptoms table)
OK:
There are no foreign objects on any valves and they operate smoothly.
NG -- REPAIR OR REPLACE TRANSMISSION VALVE BODY ASSEMBLY
OK -- REPAIR OR REPLACE AUTOMATIC TRANSMISSION ASSEMBLY