P0756
A246E AUTOMATIC TRANSAXLE: P0756: Shift Solenoid "B" Performance (Shift Solenoid Valve S2)
DTC P0756 - Shift Solenoid "B" Performance (Shift Solenoid Valve S2)
SYSTEM DESCRIPTION
The ECM uses signals from the vehicle speed sensor and crankshaft position sensor to detect the actual gear position (1st, 2nd, 3rd or O/D 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, and output shaft revolution, the ECM detects the actual gear position (1st, 2nd, 3rd or O/D 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), (D) and (E):
OFF malfunction (F) and (G):
OFF malfunction (H):
OFF malfunction (I):
ON malfunction (A):
ON malfunction (B):
ON malfunction (C), (D) and (E):
ON malfunction (F):
ON malfunction (G) and (H):
ON malfunction (I):
TYPICAL MALFUNCTION THRESHOLDS
[OFF malfunction]
Following conditions met (1) or (2)
(1): OFF malfunction (A)
(2): OFF malfunction (B), (C), (D), (E), (F), (G), (H)
(1)
It is necessary 2 judgments/driving cycle
1st judgment: temporary flag ON
2nd judgment: pending fault code ON
OFF malfunction (A):
(2)
There are 2 judgment steps/driving cycle
1st judgment step: when following conditions OFF malfunction (B) met, temporary flag becomes ON.
It is necessary 2 judgments/driving cycle
2nd judgment step: when following conditions met, pending fault code becomes ON.
(OFF malfunction (C), (F) and (H)) or (OFF malfunction (D), (E), (G) and (H))
OFF malfunction (B):
OFF malfunction (C:)
OFF malfunction (D):
OFF malfunction (E) and (F):
OFF malfunction (G):
OFF malfunction (H):
OFF malfunction (I):
[ON malfunction]
Following conditions met (1) or (2)
(1): ON malfunction (A)
(2): ON malfunction (B), (C), (D), (E), (F), (G), (H)
(1)
ON malfunction (A):
(2)
There are 2 judgment steps/driving cycle
1st judgment step: when following conditions ON malfunction (B) met, temporary flag becomes ON.
It is necessary 2 judgments/driving cycle
2nd judgment step: when following conditions met, pending fault code becomes ON.
(ON malfunction (D), (F) and (H)) or (ON malfunction (C), (E), (F) and (G))
ON malfunction (B)
ON malfunction (C):
ON malfunction (D):
ON malfunction (E):
ON malfunction (F):
ON malfunction (G):
ON malfunction (H):
ON malfunction (I):
INSPECTION PROCEDURE
HINT: Performing the Active Test using Techstream allows the relay, VSV, actuator and so on to operate without parts removal. Performing the Active Test as the first step of troubleshooting is one method to shorten labor time.
It is possible to display the Data List during the Active Test.
1. PERFORM ACTIVE TEST
(a) Warm up the engine.
(b) Turn the ignition switch off.
(c) Connect Techstream to the DLC3.
(d) Turn the ignition switch to the on position.
(e) Turn on the tester.
(f) Select the item "Enter / Powertrain / Engine and ECT / Active Test".
(g) According to the display on the tester, perform the "Active Test".
HINT: While driving, the shift position can be forcibly changed with 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 Techstream.
PROCEDURE
1. CHECK OTHER DTCS OUTPUT (IN ADDITION TO DTC P0756)
(a) Connect Techstream to the DLC3.
(b) Turn the ignition switch to the on position and turn the Techstream main switch on.
(c) Select the item "Powertrain / Engine and ECT / Trouble Codes".
(d) Read the DTCs using Techstream.
Result:
HINT: If any other codes besides "P0756" are output, perform the troubleshooting for those DTCs first.
B -- GO TO RELEVANT DTC CHART
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)
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
OK -- REPAIR OR REPLACE AUTOMATIC TRANSAXLE ASSEMBLY