P0756
CIRCUIT DESCRIPTION
The Powertrain Control Module (PCM) monitors the commanded gear and speed ratio in order to identify a 2-3 Shift Solenoid Valve (2-3 SS Valve) problem. When the PCM detects a gear other than 1st gear when 1st gear is commanded, then DTC P0756 sets. When the PCM detects 1st gear when 4th gear is commanded, then DTC P0756 sets. DTC P0756 is a type B DTC.
CONDITION FOR SETTING THE DTC
^ No Throttle Position (TP) DTCs P0122 or P0123.
^ No Vehicle Speed Sensor (VSS) DTC P0502.
^ No Transmission Fluid Temperature (TFT) DTCs P0712, P0713 or P1812.
^ The engine speed is greater than 500 RPM for 5 seconds.
^ Not in fuel shut off.
^ The vehicle speed is more than 32 km/h (20 mph).
^ The transmission fluid temperature is hotter than 20°C (68°F).
^ The transmission range switch indicates D4, D3, D2 or D1.
^ All of the above must occur and one of the following must be true:
FAILURE CRITERIA
Case 1
^ The throttle position is greater than 37%.
^ The PCM commands 1st gear and the speed ratio is less than 105 for 2.5 seconds (the shift valve is stuck in the OFF position).
Case 2
^ The throttle position is greater than 18%.
^ The PCM commands 4th gear and the speed ratio is greater than 100 for 2 seconds (the shift valve is stuck in the ON position).
ACTION TAKEN WHEN THE DTC SETS
The PCM illuminates the Malfunction Indicator Lamp (MIL) after two consecutive trips with a failure reported.
CONDITIONS FOR CLEARING THE DTC
^ The PCM turns OFF the MIL after three consecutive ignition cycles 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.
DIAGNOSTIC AIDS
^ Check for PRNDL DTC P0705. DTC P0705 affects transmission operation. This may set DTC P0756 falsely.
^ Inspect the transmission fluid for sediment. Inspect the transmission filter for debris.
TEST DESCRIPTION
The number below refers to the step number on the diagnostic chart.
3. Once the DTC is verified, replace the 2-3 shift solenoid.