P0776
AB60E AUTOMATIC TRANSMISSION / TRANSAXLE: AUTOMATIC TRANSMISSION SYSTEM: P0766: Shift Solenoid "D" Performance (Shift Solenoid Valve S4)
DTC P0766 - Shift Solenoid "D" Performance (Shift Solenoid Valve S4)
DTC P0776 - Pressure Control Solenoid "B" Performance (Shift Solenoid Valve SL2)
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, 5th or 6th 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:
- Gear position during fail-safe operation:
If any malfunction is detected, the ECM changes into the fail-safe mode to shift into the gear positions as shown in the table below.
MONITOR DESCRIPTION
This DTC indicates "stuck OFF malfunction" of the shift solenoid valve S4, "stuck ON malfunction" of the shift solenoid valve SL2, or brake control valve malfunction. The ECM commands gear shifts by turning the shift solenoid valves "ON/OFF". When the gear position commanded by the ECM and the actual gear position are not same, the ECM illuminates the MIL and stores the DTCs.
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
All
P0766 OFF Malfunction (A) and P0776 ON Malfunction (A)
P0766 OFF Malfunction (B) and P0776 ON Malfunction (B)
TYPICAL MALFUNCTION THRESHOLDS
[OFF malfunction]
- Both of the following conditions are met: OFF malfunction (A) and (B)
P0766 OFF Malfunction (A)
P0766 OFF Malfunction (B)
[ON malfunction]
- Both of the following conditions are met: ON malfunction (A) and (B)
P0776 ON Malfunction (A)
P0776 ON Malfunction (B)
INSPECTION PROCEDURE
1. ACTIVE 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) Warm up the engine.
(b) Turn the ignition switch off.
(c) Connect the Techstream to the DLC3.
(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:
While driving, the shift position can be forcibly changed with the Techstream.
Comparing the shift position commanded by the Active Test with the actual shift position enables you to confirm the problem Fail-Safe Chart.
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.
- The shift solenoid valve SL2 turns ON/OFF normally when the shift lever is in D.
PROCEDURE
1. CHECK DTC OUTPUT (IN ADDITION TO DTCS P0766 AND P0776)
(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 P0766 and P0776 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 -- REPLACE SHIFT SOLENOID VALVE SLT
OK -- Continue to next step.
3. 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:
(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.
NG -- REPLACE SHIFT SOLENOID VALVE S4
OK -- Continue to next step.
4. INSPECT SHIFT SOLENOID VALVE SL2
(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.
NG -- REPLACE SHIFT SOLENOID VALVE SL2
OK -- Continue to next step.
5. 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 -- REPAIR OR REPLACE AUTOMATIC TRANSMISSION ASSEMBLY