GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 1996 🢒 Corsica 🢒 DTC 🢒 DTC P0756 2-3 (B) Shift Solenoid Performance
Table 1: Shift Solenoid State and Gear Ratio
Table 2: DTC P0756 2-3 Shift Solenoid Performance

Object Number: 28123 Size: MF
Automatic Transmission Components
Automatic Transmission Controls Schematics
OBD II Symbol Description Notice

Circuit Description

The Powertrain Control Module (PCM) monitors the commanded gear and speed ratio in order to identify a 2-3 Shift Solenoid Valve (2-3 SS Valve) problem.

When the PCM detects a gear other than 1st gear when 1st gear is commanded, then DTC P0756 sets. When the PCM detects 1st gear when 4th gear is commanded, then DTC P0756 sets. DTC P0756 is a type B DTC.

Conditions for Setting the DTC
    • No TP DTCs P0122 or P0123
    • No VSS DTC P0502
    • No TFT DTCs P0712, P0713 or P1812
    • The engine speed is greater than 500 RPM for 5 seconds.
    • Not in fuel shut off
    • The vehicle speed is more than 32 km/h (20 mph).
    • The transmission fluid temperature is hotter than 20°C (68°F).
    • The transmission range switch indicates D4, D3, D2 or D1.
    • All of the above must occur and one of the following must be true:

Failure Criteria

Case 1:

    • The throttle position is greater than 37%.
    • The PCM commands 1st gear and the speed ratio is less than 106 for 2.5 seconds (the shift valve is stuck in the OFF position).

Case 2:

    • The throttle position is greater than 18%.
    • The PCM commands 4th gear and the speed ratio is greater than 100 for 2 seconds (the shift valve is stuck in the ON position).

Action Taken When the DTC Sets

The PCM illuminates the Malfunction Indicator Lamp (MIL) after two consecutive trips with a failure reported.

Conditions for Clearing the DTC
    • The PCM turns OFF the MIL after three consecutive ignition cycles without a failure reported.
    • A scan tool can clear the DTC from the PCM history. The PCM clears the DTC from the PCM history if the vehicle completes 40 warm-up cycles without a failure reported.

Diagnostic Aids
    • Check for PRNDL DTC P0705. DTC P0705 affects transmission operation. This may set DTC P0756 falsely.
    • Inspect the transmission fluid for sediment.
    • Inspect the transmission filter for debris.

Shift Solenoid State and Gear Ratio

Gear

1-2 Shift Solenoid

2-3 Shift Solenoid

Gear Ratio

1st

ON

ON

2.921:1

2nd

OFF

ON

1.568:1

3rd

OFF

OFF

1.000:1

4th

ON

OFF

0.705:1

Reverse

ON

ON

2.385:1

Test Description

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

  1. Once the DTC is verified, replace the 2-3 shift solenoid.

DTC P0756 2-3 Shift Solenoid Performance

Step

Action

Value(s)

Yes

No

1

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

--

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

2

Have you performed the fluid checking procedure?

--

Go to Step 3

Go to Transmission Fluid Check

3
  1. Install the scan tool.
  2. With the engine OFF, turn the ignition switch to the RUN position.

    3. Important: Before clearing the DTCs, use the scan tool in order to record the Freeze Frame and Failure Records for reference. The Clear Info function will erase the data.

  3. Record the DTC Freeze Frame and Failure Records.
  4. After verifying that the DTC has set, replace the 2-3 SS Valve.

    5. Refer to 2-3 Shift Solenoid Valve Replacement, in On-Vehicle Service.

Is the replacement complete?

--

Go to Step 4

--

4

In order to verify your repair, perform the following procedure:

  1. Select DTC.
  2. Select Clear Info.
  3. Operate the vehicle under the following conditions:
    4. • The transmission fluid temperature is greater than 20°C (68°F).
    • The engine speed is more than 500 RPM for 5 seconds.
    • The vehicle is not in fuel shut off.
    • Gear range is D1, D2, D3, or D4.
    • the vehicle speed is more than 32 km/h (20 mph).
    • Both of the following cases must be true:
    • Case 1
       - First gear
       - The throttle position is greater than 37%.
       - The speed ratio is greater than 106 for 2.5 seconds.
    • Case 2
       - Fourth gear
       - The throttle position is greater than 18%.
       - The speed ratio is less than 100 for 2 seconds.
  4. Select Specific DTC. Enter DTC P0756.

Has the test run and passed?

--

System OK

Begin the diagnosis again. Go to System Diagnosis Charts:

First and Second Gear Only - 2-3 Solenoid Stuck On (1-2-2-1)

Third and Fourth Gear Operation (4-3-3-4) 2nd Gear Downshifts Attainable Through Manual Gear Ranges