GM Service Manual Online
For 1990-2009 cars only
Table 1: Shift Solenoid Valve State
Table 2: DTC P0757 2-3 Shift Solenoid- Stuck On

Object Number: 398666  Size: LF
Automatic Transmission Components
Automatic Transmission Controls Schematics
OBD II Symbol Description Notice

Circuit Description

The 2-3 shift solenoid (SS) valve is a normally open shift solenoid that controls the positioning of the 2-3 shift valve. When energized (on), the shift solenoid is closed and blocks D32/1-2 fluid from acting on the solenoid end of the 2-3 shift valve. When de-energized (off), the solenoid opens and D32/1-2 fluid pressure flows through the solenoid, acts on the solenoid end of the shift valve and moves the valve against spring force.

When the TCM detects a 1-2-2-1 shift pattern, then DTC P0757 will set. DTC P0757 is a type B DTC.

Conditions for Running the DTC

    • Transmission is in drive (D).
    • No Transmission Range Switch DTC P0705.
    • No VSS Assembly DTC P0722.
    • No 1-2/3-4 SS Valve DTC P0753.
    • No 2-3 SS Valve DTC P0758.
    • No TCM Internal Watchdog Operation DTC P1600.
    • No TCM Power Relay Control Circuit-Shorted DTC P1625.
    • No TCC Enable Solenoid Circuit - Electrical DTC P0743.
    • No Throttle Position Signal DTC P1890.

All the above conditions must be present, plus one of the following conditions:

Condition 1:

    • The commanded gear is 3rd for greater than 0.7 seconds.
    • Throttle position is greater than 26.4%.
    • Engine speed is 3104 to 4192 RPM.
    • Transmission output speed is greater than 1088 RPM.
    • Engine torque is greater than 50 N·m (68 lb ft).

Condition 2:

    • The commanded gear is 4th for greater than 0.5 seconds.
    • Throttle position is greater than 13.8%.
    • Engine speed is 3008 to 6016 RPM.
    • Transmission output speed is greater than 1216 RPM.
    • Engine torque is greater than 0 N·m (0 lb ft).

Conditions for Setting the DTC

DTC P0757 sets if the following conditions occur two times.

Condition 1:

TCC slip speed is 1200 to 1800 RPM for 3.0 seconds.

Condition 2:

TCC slip speed is 2000 to 6000 RPM for 1.3 seconds.

Action Taken When the DTC Sets

    • Early production - The TCM illuminates the service transmission lamp (STL) and sends a MIL request to the ECM on the second consecutive drive trip that the diagnostic runs and fails. The ECM then illuminates the MIL.
    • Late production - The TCM flashes the Sport Mode Lamp and sends a MIL request on the second consecutive drive trip that the diagnostic runs and fails. The TCM then illuminates the MIL.
    • The ECM records the operating conditions in the Freeze Frame at the time of the MIL request from the TCM.
    • The transmission operates in the default mode (maximum line pressure, command 4th gear, inhibit TCC, freeze shift adapts).

Conditions for Clearing the MIL/DTC

    • Early production - The TCM turns off the STL as soon as the fault is no longer present.
    • Late production - The TCM stops flashing the sport mode lamp as soon as the fault is no longer present.
    • The ECM turns off the MIL after three consecutive drive trips during which the TCM sends no MIL request.
    • A History DTC clears after forty consecutive warm-up cycles, if no failures are present by this diagnostic or any other emission related diagnostic.
    • The scan tool clears the MIL/DTC.
    • The TCM cancels the DTC default mode actions when the fault no longer exists and the ignition switch is Off long enough in order to power down the TCM.

Diagnostic Aids

    • Vehicles equipped with Fuel Cap Lamps utilize the Sport Mode lamp to indicate a transmission malfunction. In these vehicles, the Sport Mode Lamp flashes at 200 millisecond intervals when the TCM commands the lamp ON.
    • Vehicles not equipped with Fuel Cap Lamps are equipped with a dedicated Service Transmission Lamp (STL) on the Instrument Panel Cluster (IPC). The STL illuminates steadily when the TCM commands the lamp ON.
    • Verify that the transmission meets the specifications in the Shift Speeds table.
    • Other internal transmission failures may cause more than one shift to occur.
    • Refer to the Shift Solenoid Valve State table:

Shift Solenoid Valve State

 

1

2

3

D

1-2/3-4 Shift Solenoid

OFF

ON

ON

OFF

2-3 Shift Solenoid

ON

ON

OFF

OFF

Test Description

The number below refers to the step number on the diagnostic table.

  1. This step tests that the TCM commanded all shifts, that all shift solenoid valves responded correctly, but that all the shifts did not occur.

DTC P0757 2-3 Shift Solenoid- Stuck On

Step

Action

Value(s)

Yes

No

1

Was the Powertrain On-Board Diagnostic (OBD) System Check performed?

--

Go to step 2

Go to On-Board Diagnostic System Check

2

  1. Install the Scan Tool .
  2. With the engine OFF, turn the ignition switch to the RUN position.
  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 ECM/TCM.

  4. Record the DTC Freeze Frame and Failure Records.
  5. Clear the DTC.
  6. Drive the vehicle in D4 range, under the following condition:
  7. Accelerate the vehicle, ensuring that the TCM commands 1st, 2nd, 3rd and 4th gears.

Was a 1-2-2-1 shift pattern detected?

--

Go to Step 3

Go to Diagnostic Aids

3

  1. Inspect the 2-3 shift circuit for the following conditions:
  2. • 2-3 shift solenoid valve (2-3 SS Valve) mechanically stuck OFF
    • Damaged 2-3 SS valve O-ring
    • 2-3 shift valve stuck in the released position
  3. Repair the circuit. Refer to Unit Repair.

Was the condition found and corrected?

--

Go to Step 4

--

4

Perform the following procedure in order to verify the repair:

  1. Clear DTCs.
  2. For condition 1, drive the vehicle in D4 and ensure the following conditions are met:
  3. • Throttle position is at least 10%.
    • TCM has commanded 3rd gear.
    • Engine speed is less than 2016 RPM.
    • Transmission output speed is greater than 1696 RPM.
    • Engine torque is greater than 50 N·m (68 lb ft).
    • TCC slip speed is -32 to +32 RPM for 3 seconds.
  4. For condition 2, drive the vehicle in D4 and ensure the following conditions are met:
  5. • Throttle position is at least 10%.
    • TCM has commanded 4th gear.
    • Engine speed is 1696 to 3488 RPM.
    • Transmission output speed is greater than 2400 RPM.
    • Engine torque is greater than 50 N·m (68 lb ft).
    • TCC slip speed is -32 to +32 RPM for 3 seconds.

Did the transmission shift through all drive ranges as commanded by the TCM?

--

System OK

Go to Step 1