P0751

DTC P0748









Circuit Description with 4T65-E Automatic Transaxle
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 four different shifting combinations. The 1-2 SS valve is attached to the lower control valve body, within the transmission.
The PCM monitors the actual gear ratio, and compares the actual gear ratio with the commanded gear ratio. DTC P0751 sets under two conditions:
^ A stuck OFF 1-2 SS valve
^ A stuck OFF 1-2 shift valve
If the PCM 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 TP DTCs P0121, P0122 or P0123.
^ No VSS DTCs P0502 or 1:10503.
^ No AT ISS DTCs P0716 or P0717.
^ No IMS DTCs P1820, P1822, P1823 or P1825.
^ No shift solenoid electrical DTCs P1842, P1843, P1845 or P1847.
^ The engine run time is greater than 5 seconds.
^ The IMS indicates D1, D2, D3 or D4.
^ The transmission fluid temperature is 20 - 133°C (68 - 271°F).
^ The TP angle is 7.5 percent or greater.
^ The vehicle speed is 8 km/h (5 mph) or greater.
^ The engine torque is 80 - 395 Nm (59 - 291 ft. lbs.).

Conditions for Setting the DTC
The following conditions occur twice during the same trip:
^ The PCM commands 1st gear and the gear ratio is 1.54:1-1.71:1, 2nd gear, for 1.5 seconds.
^ The PCM commands 4th gear and the gear ratio is 0.95:1-1.05:1, 3rd gear, for 4 seconds.

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 commands maximum line pressure.
^ The PCM inhibits TCC engagement.
^ The PCM freezes transmission adapt functions.
^ 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 during the second consecutive trip in which the Conditions for Setting the DTC are met.

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.

Diagnostic Aids
^ If you clear DTC P0751, and then cannot reset DTC P0751, the following conditions may exist:
- 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.