P0766

U241E AUTOMATIC TRANSAXLE: AUTOMATIC TRANSAXLE SYSTEM: P0766: Shift Solenoid "D" Performance (Shift Solenoid Valve S4)

DTC P0766 - Shift Solenoid "D" Performance (Shift Solenoid Valve S4)

SYSTEM DESCRIPTION

The ECM uses signals from the output shaft speed sensor and input speed sensor to detect the actual gear position (1st, 2nd, 3rd or 4th 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 transaxle (clutch, brake, gear, etc.).






MONITOR DESCRIPTION

This DTC indicates a 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 the same, the ECM illuminates the MIL and stores the DTC.

MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS

All





OFF Malfunction





ON Malfunction





TYPICAL MALFUNCTION THRESHOLDS

Either of the following conditions is met:
OFF malfunction or ON malfunction
2 detections are necessary per driving cycle:
1st detection: temporary flag ON
2nd detection: pending fault code ON

OFF Malfunction





ON Malfunction





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) Follow the instructions on the Techstream and 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.





HINT:
- This test can be conducted when the vehicle speed is 50 km/h (31 mph) or more.
- This shift position commanded by the ECM is shown in the Data List/Shift display on the Techstream.

PROCEDURE

1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0766)
(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 are output, perform troubleshooting for those DTCs first.

B -- GO TO DTC CHART
A -- Continue to next step.
2. 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 body. Then check that the valve moves and makes an operating sound.
OK:
Valve moves and makes operating sound.
NG -- REPLACE SHIFT SOLENOID VALVE S4
OK -- Continue to next step.
3. 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.
4. 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 TRANSAXLE ASSEMBLY