4T40-E / 4T45-E Automatic Transaxle

DTC P0752





Circuit Description with 4T40-E / 4T45-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 4 different shifting combinations. The 1-2 SS valve is attached to the control valve body, within the transmission.

The transmission control module (TCM) monitors the actual gear ratio, and compares the actual gear ratio with the commanded gear ratio. DTC P0752 sets under 2 conditions:
^ A stuck ON 1-2 SS valve
^ A stuck ON 1-2 shift valve

When the TCM detects a 1-1-4-4 shift pattern, then DTC P0752 sets. DTC P0752 is a type B DTC.

DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P0752 1-2 Shift Solenoid (SS) Valve Performance - No Second or Third Gear

Conditions for Running the DTC
^ No MAP DTCs P0107 or P0108.
^ No TP DTCs P0122 or P0123.
^ No ISS DTCs P0716 or P0717.
^ No VSS DTCs P0722 or P0723.
^ No TCC stuck ON DTC P0742.
^ No SS electrical DTCs P0973, P0974, P0976, P0977.
^ The engine run time is greater than 5 seconds.
^ The transmission fluid temperature (TFT) is 20 - 130°C (68 - 233°F).
^ The TP is greater than 8 percent.
^ The engine torque is greater than 50 Nm (37 ft. lbs.).
^ The vehicle speed is greater than 8 km/h (5 mph).

Conditions for Setting the DTC
The following occurs twice during the same trip:
^ The TCM commands 2nd gear and the gear ratio is 2.81:1-3.10:1, 1st gear, for 2 seconds.
^ The TCM commands 3rd gear and the gear ratio is 0.64:1-0.71:1, 4th gear, for 2 seconds.

Action Taken When the DTC Sets
^ The TCM requests the engine control module (ECM) to illuminate the malfunction indicator lamp (MIL) during the second consecutive trip in which the Conditions for Setting the DTC are met.
^ The TCM commands maximum line pressure.
^ The TCM inhibits 3-2 downshifts above 51 km/h (32 mph).
^ The TCM freezes transmission adaptive functions.
^ The ECM records the operating conditions when the Conditions for Setting the DTC are met. The ECM stores this information as Freeze Frame and Failure Records.
^ The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as Failure Records.
^ The TCM stores DTC P0752 in TCM history during the second consecutive trip in which the Conditions for Setting the DTC are met.

Conditions for Clearing the MIL/DTC
^ The ECM turns OFF the MIL after the third consecutive drive trip in which the TCM does not send a MIL illumination request.
^ A scan tool can clear the MIL/DTC.
^ The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring.
^ The TCM cancels the DTC default actions when the ignition switch is OFF long enough in order to power down the TCM.

Diagnostic Aids
^ If you clear DTC P0752, and then cannot set DTC P0752 again, inspect for the following conditions:
^ Fluid contamination
^ Plugged fluid circuits
^ Restricted fluid circuits

Test Description





The numbers below refer to the step numbers on the diagnostic table.
3. This step verifies a 1-1-4-4 shift pattern.
4. This step tests for a mechanical or hydraulic condition causing the 1-2 SS valve to be stuck ON, or the circuit to be applied.