With Powertrain Control Module
Performance:
CIRCUIT DESCRIPTION
The 1-2 Shift Solenoid Valve (1-2 SS Valve) Controls the fluid flow action on the 1-2 and the 3-4 shift valves. The 1-2 SS Valve is a normally-open exhaust valve that is used with the 2-3 Shift Solenoid Valve (2-3 SS Valve) to allow four different shifting combinations.
When the Powertrain Control Module (PCM) detects a 2-2-3-3 or a 1-1-4-4 gear ratio, then DTC P0751 sets. DTC P0751 is a type B DTC.
CONDITIONS FOR SETTING THE DTC
^ No MAP Sensor DTCs P0106, P0107, or P0108.
^ No OSS DTCs P0722 or P0723.
^ No A/T ISS Sensor DTCs P0716 or P0717.
^ No TCC DTCs P0741 or P0742.
^ No 1-2 SS Valve DTC P0753.
^ No 2-3 SS Valve DTC P0758.
^ No Automatic Transmission Fluid Pressure Manual Valve Position Switch (TFP Val. Position Sw.) DTC P1810.
^ The engine must be running greater than 475 RPM for at least 7 seconds.
^ The vehicle speed is greater than 3.2 km/h (2 mph).
^ The APP Angle is greater than 10%.
^ System voltage is 9.0-16.0 volts.
^ The Engine Torque is 108-644 N.m (80-475 lb. ft).
^ The transmission fluid temperature is greater than 20°C (68°F) and less than 130°C (255°F).
^ The engine speed is less than 3750 RPM.
^ All the above conditions are met and one of the following conditions occur:
Stuck Off (for two occurrences)
^ First gear is commanded and the gear ratio is equal to second gear for greater than 1.5 seconds.
^ Fourth gear is commanded (with TCC locked) and the gear ratio equals third gear for greater than 3 seconds.
Stuck On (for five occurrences)
Second gear is commanded and the gear ratio equals first gear for greater than 2.2 seconds.
ACTION TAKEN WHEN THE DTC SETS
^ The PCM illuminates the Malfunction Indicator Lamp (MIL).
^ The PCM commands maximum line pressure.
^ The PCM freezes shift adapts. DTC P0751 is stored in the PCM history.
CONDITIONS FOR CLEARING THE MIL/DTC
^ The PCM turns OFF the MIL after three consecutive trip5 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.
^ 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 whether the scan tool commanded all the shifts, or whether all the shift solenoids responded correctly but all the shifts did not occur.