U151E Automatic Transaxle
U151E AUTOMATIC TRANSAXLE: AUTOMATIC TRANSAXLE SYSTEM: P0771: Shift Solenoid "E" Performance (Shift Solenoid Valve SR)
P0771 - Shift Solenoid "E" Performance (Shift Solenoid Valve SR)
DESCRIPTION
The ECM uses signals from the vehicle 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 transaxle (clutch, brake, gear, etc.).
MONITOR DESCRIPTION
The ECM commands gear shifts by turning the shift solenoid valves ON/OFF. According to the input shaft revolution, intermediate (counter) shaft revolution and output shaft revolution, the ECM detects the actual gear position (1st, 2nd, 3rd, 4th or 5th gear position). 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 (A)
OFF malfunction (B)
ON malfunction (A)
ON malfunction (B)
ON malfunction (C)
ON malfunction (D)
TYPICAL MALFUNCTION THRESHOLDS
* Either condition is met: OFF malfunction or ON malfunction
OFF malfunction
* Both conditions are met: OFF malfunction (A) and (B)
OFF malfunction (A)
OFF malfunction (B)
ON malfunction
* All conditions are met: ON malfunction (A), (B), (C) and (D)
ON malfunction (A)
ON malfunction (B) and (C)
ON malfunction (D)
INSPECTION PROCEDURE
NOTICE:
Perform the universal trip to clear permanent DTCs .
HINT
Performing Techstream's 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.
1. Warm up the engine.
2. Turn the ignition switch off.
3. Connect Techstream to the DLC3.
4. Turn the ignition switch to ON and turn the Techstream on.
5. Enter the following menus: Powertrain / Engine and ECT / Active Test.
6. 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 .
ECM:
HINT
- This test can be conducted when the vehicle speed is 50 km/h (31 mph) or less.
- The shift position commanded by the ECM is shown in the Data List/Shift Status display on the Techstream.
PROCEDURE
1. CHECK OTHER DTC OUTPUT (IN ADDITION TO DTC P0771)
(a) Connect Techstream to the DLC3.
(b) Turn the ignition switch to ON and turn the Techstream on.
(c) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
(d) Read the DTCs using the Techstream.
Result:
HINT
If any other codes besides P0771 are output, perform troubleshooting for those DTCs first.
B -- GO TO DTC CHART
A -- Continue to next step.
2. INSPECT SHIFT SOLENOID VALVE SR
(a) Remove the shift solenoid valve SR.
(b) Measure the resistance between the solenoid valve terminal and solenoid valve body.
Standard resistance:
11 to 15 Ohms at 20°C (68°F)
(c) Connect the battery's 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 noise.
OK:
Valve moves and makes operating noise.
NG -- REPLACE SHIFT SOLENOID VALVE SR
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 .
OK:
The torque converter clutch operates normally.
NG -- REPLACE TORQUE CONVERTER CLUTCH ASSEMBLY
OK -- REPAIR OR REPLACE AUTOMATIC TRANSAXLE ASSEMBLY