Circuit Description
The 1-2 shift solenoid (SS) valve controls the fluid flow acting on the 1-2 and 3-4 shift valves. The 1-2 SS valve is a normally-open exhaust valve that is used with the 2-3 SS valve, in order to allow 4 different shifting combinations.
When the transmission control module (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 output shaft speed (OSS) DTCs P0722 or P0723. |
| • | No torque converter clutch (TCC) performance DTC P0742 or P0894. |
| • | No shift solenoid electrical DTCs P0973, P0974, P0976, or P0977. |
| • | Ignition voltage between 8-18 volts. |
| • | The engine run time is greater than 5 seconds. |
| • | The transmission fluid temperature is 20-130°C (68-266°F). |
| • | The throttle position is greater than 10 percent. |
| • | The output shaft speed is greater than 150 RPM. |
| • | The engine torque is between 108 N·m (80 lb ft) and 882 N·m (651 lb ft). |
Conditions for Setting the DTC
The TCM commands 2nd gear and the resulting gear ratio is 2.42:1-2.52:1, 1st gear ratio for 2 seconds twice during the same trip.
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 freezes transmission adaptive functions. |
| • | The TCM inhibits 3-2 downshifts if the vehicle speed is greater than 40 km/h (25 mph). |
| • | At the time of the first failure, the TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as a Failure Record. |
| • | At the time of the second failure, the ECM records the operating conditions when the Conditions for Setting the DTC are met. The ECM stores this information as a Freeze Frame. |
| • | 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 DTC
| • | The ECM turns OFF the MIL after the 4th consecutive drive trip in which the TCM does not send a MIL illumination request. |
| • | A scan tool can clear the DTC. |
| • | The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without a non-emission related diagnostic fault occurring. |
| • | The TCM cancels the DTC default actions when the ignition is OFF long enough in order to power down the TCM. |
Diagnostic Aids
| • | If you clear DTC P0752, and then cannot reset DTC P0752, 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 number below refers to the step number on the diagnostic table.
-
This step tests that the TCM commanded all shifts, that all shift solenoid valves responded correctly, but that all the shifts did not occur.
Step | Action | Values | Yes | No | ||||
|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | |||||
2 |
Important: Before clearing the DTC, use the scan tool in order to record the Freeze Frame and Failure Records. Using the Clear Info function erases the Freeze Frame and Failure Records from the transmission control module (TCM). Accelerate the vehicle, ensuring that the TCM commands 1st, 2nd, 3rd and 4th gears. Did you detect a 1-1-4-4 shift pattern? | -- | Go to Step 3 | Go to Diagnostic Aids | ||||
3 | Inspect the shift solenoid/hydraulic circuit for the following conditions:
Did you find and correct the condition? | -- | Go to Step 4 | -- | ||||
4 | Perform the following procedure in order to verify the repair:
Hold the throttle at 20 percent and accelerate to 88 km/h (55 mph). Has the test run and passed? | -- | Go to Step 5 | Go to Step 2 | ||||
5 | With the scan tool, observe the stored information, capture info, and DTC Info. Does the scan tool display any DTCs that you have not diagnosed? | -- | System OK |
