GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2006 🢒 Classic 🢒 Transmission/Transaxle 🢒 Automatic Transaxle - 4T45-E 🢒 DTC P0757

Object Number: 40582 Size: SF
Master Electrical Component List
Automatic Transmission Controls Schematics
OBD II Symbol Description Notice

Circuit Description

The 2-3 shift solenoid (SS) valve is a normally-open exhaust valve that, in conjunction with the 1-2 shift solenoid (SS) valve, allows four different shifting combinations. Refer to Shift Solenoid Valve State and Gear Ratio . The 2-3 SS valve is attached to the control valve body, within the transmission.

The powertrain control module (PCM) monitors the actual gear ratio, and compares the actual gear ratio with the commanded gear ratio. DTC P0757 sets under two conditions:

    • A stuck OFF 2-3 SS valve
    • A stuck OFF 2-3 shift valve

When the PCM detects a 1-2-2-1 shift pattern, then DTC P0757 sets. DTC P0757 is a type A DTC.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0757 2-3 Shift Solenoid (SS) Valve Performance - No Third, Fourth or Fifth Gear

Conditions for Running the DTC
    • No MAP DTCs P0106, P0107, or P0108.
    • No TP DTCs P0122 or P0123.
    • No OSS DTCs P0502 or P0503.
    • No ISS DTCs P0716 or P0717.
    • No TCC stuck ON DTC P0742.
    • No shift solenoid electrical DTCs P0753 or P0758.
    • No TCC electrical DTC P2761.
    • The transmission fluid temperature (TFT) is 20-130°C (68-266°F).
    • The throttle position (TP) is greater than 8 percent.
    • The input speed is 150-6,500 RPM.
    • The output speed is greater than 150 RPM.
    • The time since the last gear change is 1 second or greater.
    • The engine torque is greater than 39 N·m (29 lb ft) when 3rd gear is commanded.

Conditions for Setting the DTC

The following occurs twice during the same trip:

    • The PCM commands 3rd gear and the gear ratio is 1.54:1-1.71:1, 2nd gear, for 2 seconds.
    • The PCM commands 4th gear and the gear ratio is 1.87:1-3.13:1, 1st gear, for 2 seconds.

Action Taken When the DTC Sets
    • The PCM illuminates the malfunction indicator lamp (MIL).
    • The PCM commands maximum line pressure.
    • The PCM forces the torque converter clutch (TCC) OFF.
    • The PCM inhibits TCC engagement.
    • The PCM freezes transmission adaptive functions.
    • The PCM inhibits 4th gear when in HOT mode.
    • 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 P0757 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
    • If you clear DTC P0757, and then cannot set DTC P0757 again, inspect for the following conditions:
       - 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.

  1. This step verifies a 1-2-2-1 shift pattern.

    2.

  2. This step tests for a mechanical or hydraulic condition causing the 2-3 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 - Vehicle?

--

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

Did you perform the Transmission Fluid Checking Procedure?

--

Go to Step 3

Go to Transmission Fluid Check

3

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.

    3. 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 PCM.

  3. Record the DTC Freeze Frame and Failure Records.
  4. Clear the DTC.
  5. Use the scan tool snapshot mode in order to record current gear and gear ratio.
  6. Drive the vehicle in D4, in order to obtain a 1-2, 2-3 and 3-4 shifts with a TP greater than 8%.

Are current gear and gear ratio within the specified values?

1st/4th:

2.87:1-3.13:1

2nd/3rd:

1.54:1-1.71:1

Go to Step 4

Go to Diagnostic Aids

4
  1. Inspect the 2-3 shift circuit for the following conditions:
    2. • 2-3 SS valve mechanically stuck OFF
    • 2-3 shift valve stuck in the released position
    • Refer to Shift Solenoid Leak Test .
    • Damaged 2-3 SS valve O-ring
  2. Repair the circuit as necessary.

Refer to 2-3 Shift Solenoid Valve Replacement .

Did you complete the repair?

--

Go to Step 5

--

5

Perform the following procedure in order to verify the repair:

  1. Select DTC.
  2. Select Clear Info.
  3. Operate the vehicle under the following conditions:
    4. • Drive the vehicle in D4.
    • Allow the transmission to shift through all the gears.
    • Monitor the current gear and gear ratios. The actual gear ratios must match the commanded gears for 1 second, for all gears.
  4. Select Specific DTC.
  5. Enter DTC P0757.

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 - Vehicle

System OK