P0751
DTC P0751
Circuit Description
The shift solenoid (SS) 1 is mounted to the transmission case and is used to supply or cut off the modulated pressure to the shift valve A, according to the powertrain control module (PCM) command. The signal from the PCM is output, so that a clutch control pressure is supplied to the clutch of an appropriate gear position as determined by the shift schedule. When the PCM commands the SS 1 ON, the modulated pressure is not supplied to shift valve A, and shift valve A is pushed by the reactive force of spring A. When the PCM command is OFF, the modulated pressure is supplied to the valve. The PCM monitors mainshaft to countershaft speed ratio in the gear positions determined by the shift schedule. When the incorrect ratio for the commanded gear is detected, the PCM determines it as a fault and DTC P0751 sets. DTC P0751 is a type B DTC.
Conditions for Running the DTC
- No TP DTCs P0122, P0123, P0222, or P0223.
- No VSS DTCs P0501, P0502, or P0503.
- No DTC P0705.
- No AT ISS DTCs P0716, P0717, or P0718.
- No Clutch PC Solenoid 1 DTC P0746 or P0747.
- No SS Valve Performance DTCs P0752, P0756, P0757, P0761, or P0762.
- No Clutch PC Solenoid 2 P0776 or P0777.
- No Incorrect Shift Pattern DTC P0780.
- No Clutch PC Solenoid Electrical DTCs P0962 or P0963.
- No Clutch PC Solenoid 2 DTCs P0966 or P0967.
- No SS I DTCs P0973 or P0974.
- No SS 2 DTCs P0976 or P0977.
- No SS 3 DTCs P0979 or P0980.
- No TAC DTCs P211 1, P2112, P21 01, P2108, or P2553.
- No APP DTC P2122, P2123, P2127, P2128, P2135, or P2138.
- No Minimum Idle Position DTC P2176.
- No TCC PC solenoid DTCs P2763 or P2764.
- No TCC enable solenoid DTCs P2769 or P2770.
- No TAC communication DTC: U0107.
- The system voltage is 11 volts or greater.
- The transmission fluid temperature (TFT) is -13° (-25°C) or greater.
- Start the engine and drive so that the transmission shifts from 1st to 5th gear.
- The APP is greater than 5%.
Conditions for Setting the DTC
- The gear shifts to 3rd gear in response to a 1-2 upshift command.
- The gear remains in 4th gear in response to a 4-5 upshift command, when there is no history indicating a short shift time at a preceding 3-4 upshift operation.
Action Taken When the DTC Sets
- The PCM illuminates the malfunction indicator lamp (MIL) during the second consecutive trip in which the Conditions for Setting the DTC are met.
- The PCM limits the transmission shift to 4th gear.
- The PCM records the operating conditions when the Conditions for Setting the DTC are met. The PCM stores this information as Freeze Frame and Failure Records.
- The PCM stores DTC P0751 in PCM history.
Conditions for Clearing the MIL/DTC
- The PCM turns OFF the MIL during the third consecutive trip in which the diagnostic test runs and passes.
- A scan tool can clear the MIL/DTC.
- The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without an emission related diagnostic fault occurring.
- The PCM cancels the DTC default actions when the ignition switch is OFF long enough in order to power down the PCM.
Diagnostic Aids
- Inspect for a stuck OFF shift solenoid A.
- Inspect for a stuck shift valve A.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
2. This step inspects the transmission fluid to ensure that it is at the proper level.
4. During the SS valve 1 operation, listen for an audible click. Command the ON and the OFF states. Repeat the commands as necessary.
Steps 1 - 8:
DTC P0751