P0756
U341E AUTOMATIC TRANSAXLE: AUTOMATIC TRANSAXLE SYSTEM: P0756: Shift Solenoid "B" Performance (Shift Solenoid Valve S2)
P0756 - Shift Solenoid "B" Performance (Shift Solenoid Valve S2)
DESCRIPTION
The ECM uses signals from the vehicle speed sensor and speed sensor NT 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 the mechanical problems of the shift solenoid valves, the valve body or automatic transaxle (clutch, brake or 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 or 4th gear position). When the gear position commanded by the ECM and the actual gear position are not same, the ECM illuminates the MIL and stores the DTC.
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
All
OFF malfunction (A)
OFF malfunction (B)
OFF malfunction (C)
ON malfunction (A)
ON malfunction (B)
ON malfunction (C)
TYPICAL MALFUNCTION THRESHOLDS
[OFF malfunction]
- All of the following conditions met: OFF malfunctions (a), (b) and (c)
2 detections are necessary per driving cycle.
1st detection: Temporary flag ON
2nd detection: Pending fault code ON
OFF malfunction (A)
OFF malfunction (B)
OFF malfunction (C)
[ON malfunction]
- All of the following conditions met: ON malfunctions (a), (b) and ( C)
ON malfunction (A)
ON malfunction (B)
ON malfunction (C)
INSPECTION PROCEDURE
NOTICE:
Perform the universal trip to clear permanent DTCs Reading and Clearing Diagnostic Trouble Codes.
HINT
Using a 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.
1. PERFORM ACTIVE TEST
(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.
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 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 other codes besides "P0756" are output, perform the troubleshooting for those DTCs first.
B -- GO TO DTC CHART Automatic Transaxle System - U341E
A -- Continue to next step.
2. 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 positive (+) lead to the terminal of the solenoid connector, and the negative (-) lead to the solenoid body.
OK:
The solenoid makes an operating sound.
NG -- REPLACE SHIFT SOLENOID VALVE S2 Disassembly
OK -- Continue to next step.
3. INSPECT TRANSMISSION VALVE BODY ASSEMBLY
OK:
There are no foreign objects on each valve and they operate smoothly.
NG -- REPAIR OR REPLACE TRANSMISSION VALVE BODY ASSEMBLY Removal
OK -- REPAIR OR REPLACE AUTOMATIC TRANSAXLE ASSEMBLY Removal