With Powertrain Control Module

Performance:

CIRCUIT DESCRIPTION

The 2-3 Shift Solenoid Valve (2-3 SS Valve) controls fluid flow acting on the 2-3 shift valve. The 2-3 SS Valve is a normally-open exhaust valve that is used with the 1-2 Shift Solenoid Valve (1-2 SS Valve) to allow four different shift combinations.

When the Powertrain Control Module (PCM) detects a non first gear ratio while first gear is commanded or a first gear ratio while fourth gear is commanded, then DTC P0756 sets. DTC P0756 is a type A DTC.

CONDITIONS FOR SETTING THE DTC

^ No TFT Sensor DTCs P0712 or P0713.

^ No A/T ISS Sensor DTCs P0716 or P0717.

^ No OSS Sensor DTCs P0722 or P0723.

^ No shift solenoid electrical DTCs P0753 or P0758.

^ No Automatic Transmission Fluid Pressure Manual Valve Position Switch (TFP Val. Position Sw.) DTC P1810.

^ System voltage is 9.0-16.0 volts.

^ The vehicle speed is greater than 3.2 km/h (2 mph).

^ The APP Angle is greater than 10%.

^ The Transmission Fluid Temperature (TFT) is 20°-130°C (68°-266°F).

^ The engine torque is 100-844 N.m (80-475 lb. ft).

^ The engine speed is 475-3750 RPM for at least 7 seconds.

^ All of the above conditions are met and either of the two following conditions occur:

Stuck On (after 2 occurrences)

^ First gear is commanded and the ratio equals 4th gear for greater than 2.75 seconds.

^ Second gear is commanded and the gear ratio equals 3rd for greater than 2.75 seconds.

Stuck Off (after 7 Occurrences)

Third gear is commanded and the gear ratio equals 2nd for greater than 3.25 seconds.


ACTION TAKEN WHEN THE DTC SETS

^ The PCM illuminates the Malfunction Indicator Lamp (MIL).

^ The PCM commands 2nd gear.

^ The PCM commands maximum line pressure.

^ The PCM freezes shift adapts.

^ DTC P0756 is stored in PCM history.

CONDITIONS FOR CLEARING THE MIL/DTC

^ The PCM turns OFF the MIL after three consecutive trips without a failure reported.

^ A scan tool can clear the DTC from the PCM history. The PCM clears the DTC from the PCM history if the vehicle completes 40 warm-up cycles without a failure reported.

^ The PCM cancels the DTC default actions when the fault no longer exists and the ignition is OFF long enough in order to power down the PCM.


DIAGNOSTIC AIDS

^ Verify that the transmission meets the specifications in the Shift Speed table.

^ Other internal transmission failures may cause similar shift patterns.

^ The customer may complain of an engine over-rev condition or neutral condition in 4th gear.

^ First diagnose and clear any engine DTCs or APP Sensor codes that are present. Then inspect for any transmission DTCs that may have reset.

^ Refer to Shift Solenoid Valve State and Gear Ratio table.

TEST DESCRIPTION

The numbers below refer to the step numbers on the diagnostic table.

2. This step tests the function of the TFP Val. Position Sw.

3. This step tests for a selected gear ratio versus a ratio not obtainable under normal driving conditions.