P0751
DTC P0751 Shift Solenoid "A" Performance (Shift Solenoid Valve S1)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.).
P0751:
HINT:
^ Gear positions in the event of a solenoid valve mechanical problem:
N*: Neutral
^ 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.
*3: Under engine braking downshifting to 1st or 2nd gear is prohibited.
MONITOR DESCRIPTION
This DTC indicates "stuck ON malfunction" or "stuck OFF malfunction" of the shift solenoid valve S1. 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
Part 1:
Part 2:
TYPICAL MALFUNCTION THRESHOLDS
Part 1:
Part 2:
INSPECTION PROCEDURE
1. ACTIVE TEST
HINT:
Performing the intelligent tester'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.
(a) Warm up the engine.
(b) Turn the ignition switch OFF.
(c) Connect the intelligent tester to the CAN VIM. Then connect the CAN VIM to the DLC3.
(d) Turn the ignition switch ON.
(e) Turn the intelligent tester ON.
(f) Enter the following menus: DIAGNOSIS / OBD/MOBD / ECT / ACTIVE TEST.
(g) Perform the ACTIVE TEST using the intelligent tester.
HINT:
While driving, the shift position can be forcibly changed with the intelligent tester.
Comparing the shift position commanded by the ACTIVE TEST with the actual shift position enables you to confirm the problem.
HINT:
^ This test can be conducted when the vehicle speed is 50 km/h (31 mph) or less.
^ The 4th -> 5th and 5th -> 6th up-shiftings must be performed with the accelerator pedal released.
^ The 6th -> 5th and 5th -> 4th down-shiftings 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 (SHIFT) display on the intelligent tester.
^ The shift solenoid valve S1 is turned ON/OFF normally when the shift lever is on D:
Step 1(Part 1):
Steps 1(Part 2)-2(Part 1):
Steps 2(Part 2)-4:
