Circuit Description
The 1-2 shift solenoid (SS) valve is a normally-closed 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 TCM monitors the actual gear ratio, and compares the actual gear ratio with the commanded gear ratio. DTC P0752 sets under two conditions:
| • | A stuck OFF 1-2 SS valve |
| • | A stuck OFF 1-2 shift valve |
If the TCM detects a 1-1-4-4-5 shift pattern, then DTC P0752 sets. DTC P0752 is a type B DTC.
Conditions for Running the DTC
| • | No throttle system DTCs P1791 or P1795. |
| • | No OSS DTCs P0722 or P0723. |
| • | No ISS DTCs P0716 or P0717. |
| • | No IMS DTCs P1815, P1818, P1820, P1822, P1823, P1825 or P1826. |
| • | No shift solenoid electrical DTCs P1842, P1843, P1845, P1847, P1864, or P1865. |
| • | No TCC performance DTC P0742. |
| • | No engine delivered torque signal DTC P1779. |
| • | The ignition voltage is 8-18 volts. |
| • | The engine run time is greater than 5 seconds. |
| • | The IMS indicates D2, D3,D4, or D5. |
| • | The transmission fluid temperature is 20-130°C (68-266°F). |
| • | The accelerator pedal position (APP) is greater than 10 percent. |
| • | The input shaft speed is 200-6,800 RPM. |
| • | The output shaft speed is greater than 100 RPM. |
Conditions for Setting the DTC
Both of the following conditions must occur twice during the same trip:
| • | The TCM commands 2nd gear when the engine torque is 32-350 N·m (24-258 lb ft) and the resulting gear ratio is 3.33:1-3.50:1 for 2 seconds. |
| • | The TCM commands 3rd gear when the engine torque is 32-350 N·m (24-258 lb ft) and the resulting gear ratio is 0.98:1-1.03:1 for 5 seconds. |
Action Taken When the DTC Sets
| • | The TCM requests the 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 turns off the pressure control solenoid. When the pressure control solenoid is off, line pressure is at maximum and updates to the transmission adaptive pressure (TAP) memory cells are discontinued. |
| • | The TCM inhibits 3-2 downshifts if the vehicle speed is greater than 8 km/h (5 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 sixth 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 numbers below refer to the step numbers on the diagnostic table.
-
This step verifies a 1-1-4-4-5 shift pattern.
-
This step tests for a mechanical or hydraulic condition causing the 1-2 SS valve to be stuck OFF, or the circuit to be applied.
Step | Action | Value(s) | Yes | No | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Diagnostic System Check - Engine Controls? | -- | Go to Step 2 | Go to Diagnostic System Check - Engine Controls in Engine Controls - 2.6L and 3.2L | ||||||||
2 | Perform the Transmission Fluid Checking Procedure. Refer to Transmission Fluid Check . Did you perform the Transmission Fluid Checking Procedure? | -- | Go to Step 3 | Go to Transmission Fluid Check | ||||||||
Important:
Are the commanded gear and gear ratio within the specified range? | 2nd 3.33:1-3.50:1 3rd 0.98:1-1.03:1 | Go to Step 4 | Go to Intermittent Conditions in Engine Controls - 2.6L and 3.2L | |||||||||
Refer to 1-2 Shift Solenoid Valve Replacement . Did you complete the repair? | -- | Go to Step 5 | -- | |||||||||
5 | Perform the following procedure in order to verify the repair:
Has the test run and passed? | -- | Go to Step 6 | Go to Step 2 | ||||||||
6 | 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? | -- | Go to Diagnostic Trouble Code (DTC) List in Engine Controls - 2.6L and 3.2L | System OK |
