P0751

DTC P0751 (3.0L)

Circuit Description
The 1-2 Shift Solenoid (SS) valve is a normally-open exhaust valve that, in conjunction with the 2-3 Shift Solenoid (SS) valve, allows 4 different shifting combinations. The 1-2 SS valve is attached to the control valve body, within the transmission.

The TCM monitors the actual gear ratio, and compares the actual gear ratio with the commanded gear ratio. DTC P0751 sets under 2 conditions:
^ A stuck OFF 1-2 SS valve
^ A stuck OFF 1-2 shift valve

When the TCM detects a 2-2-3-3 shift pattern, then DTC P0751 sets. DTC P0751 is a type B DTC.

Conditions for Running the DTC
^ No MAP DTCs P0101, P0102, or P0103.
^ No MAP DTCs P0107 or P0108.
^ No TP DTCs P0121, P0122, or P0123.
^ No VSS DTCs P0502 or P0503.
^ No ISS DTCs P0716 or P0717.
^ No shift solenoid electrical DTCs P1842, P1843, P1845, or P1847.
^ The engine run time is greater than 5 seconds.
^ The transmission fluid temperature is 20 - 130°C (68 - 233°F).
^ The TP is greater than 8 percent.
^ The engine torque is greater than 30 Nm (22 ft. lbs.).
^ The vehicle speed is greater than 8 km/h (5 mph).

Conditions for Setting the DTC
The following occurs twice during the same trip:
^ The TCM commands 1st gear and the gear ratio is 1.54:1 - 1.71:1, 2nd gear, for 2 seconds.
^ The TCM commands 4th gear and the gear ratio is 0.91:1 - 1.07:1, 3rd gear, for 5 seconds.

Action Taken When the DTC Sets
^ The TCM requests the ECM to illuminate the Malfunction Indicator Lamp (MIL) during the second consecutive trip in which the Conditions for Setting the DTC are met.
^ The TCM commands maximum line pressure.
^ The TCM freezes transmission adaptive functions.
^ The ECM records the operating conditions when the Conditions for Setting the DTC are met. The ECM stores this information as Freeze Frame and Failure Records.
^ The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as Failure Records.
^ The TCM stores DTC P0751 in TCM history during the second consecutive trip in which the Conditions for Setting the DTC are met.

Conditions for Clearing the MIL/DTC
^ The ECM turns OFF the MIL after the third consecutive drive trip in which the TCM does not send a MIL illumination request.
^ A scan tool can clear the MIL/DTC.
^ The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring.
^ The TCM cancels the DTC default actions when the ignition switch is OFF long enough in order to power down the TCM.

Diagnostic Aids
^ If you clear DTC P0751, and then cannot set DTC P0751 again, inspect for the following conditions:
- Fluid contamination
- Plugged fluid circuits
- Restricted fluid circuits

^ Refer to Shift Solenoid Valve State and Gear Ratio.

Test Description
The numbers below refer to the step numbers on the diagnostic table.
3. This step verifies a 2-2-3-3 shift pattern.
4. This step tests for a mechanical or hydraulic condition causing the 1-2 SS valve to be stuck OFF, or the circuit to be released.

Steps 1 - 6:

DTC P0751 (3.0L)