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Makes 🢒 Chevrolet 🢒 1999 🢒 Malibu 🢒 Engine 🢒 Engine Controls - 3.1L 🢒 DTC P0756 2-3 Shift Solenoid Valve Performance

DTC P0756 2-3 Shift Solenoid Valve Performance 2.4L and 3.1L


Object Number: 40582 Size: SF
Automatic Transmission Components
Automatic Transmission Controls Schematics
OBD II Symbol Description Notice

Circuit Description

The 2-3 shift solenoid valve (2-3 SS valve) is a normally-open exhaust valve that, in conjunction with the 1-2 shift solenoid valve (1-2 SS valve), allows 4 different shifting combinations. The 2-3 SS valve is attached to the control valve body, within the transmission. Refer to Shift Solenoid Valve State and Gear Ratio .

The PCM monitors the actual gear ratio and compares the actual gear ratio with the commanded gear ratio. DTC P0756 sets under four conditions:

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

When the PCM detects an actual gear ratio that does not agree with the commanded gear, then DTC P0756 sets. DTC P0756 is a type A DTC.

Conditions for Running the DTC
    • No TP DTCs P0121, P0122 or P0123.
    • No VSS DTCs P0502 or P0503.
    • No A/T ISS DTCs P0716 or P0717.
    • No 1-2 shift solenoid electrical DTC P0753.
    • No 2-3 shift solenoid electrical DTC P0758.
    • No engine torque DTC P1644.
    • No TFP manual valve position switch DTC P1810.
    • The engine is running.
    • The TFP manual valve position switch indicates D4, D3, D2 or D1.
    • The transmission fluid temperature is greater than 21°C (70°F).
    • The vehicle speed is greater than 8 km/h (5 mph).
    • The TP is greater than 8%.

Conditions for Setting the DTC

One of the following cases occurs:

Case 1

The following conditions occur twice during the same trip.

    • The PCM commands 1st gear and the gear ratio is 0.61:1-0.72:1 (4th gear) for 2 seconds.
    • The PCM commands 2nd gear and the gear ratio is 0.91:1-1.07:1 (3rd gear) for 2 seconds.

Case 2

    • The PCM commands 3rd gear and the gear ratio is 1.54:1-1.71:1 (2nd gear) for 3 seconds.
    • The PCM commands 4th gear and the gear ratio is 2.87:1-3.13:1 (1st gear) for 4 seconds.

Action Taken When the DTC Sets
    • The PCM illuminates the malfunction indicator lamp (MIL).
    • The PCM commands maximum line pressure.
    • The PCM commands an immediate landing to 2nd gear.
    • The PCM inhibits TCC engagement.
    • The PCM freezes shift adapts from being updated.
    • The PCM stores DTC P0756 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 clears the DTC from PCM history.
    • 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 fault no longer exists and the ignition switch is OFF long enough in order to power down the PCM.

Diagnostic Aids

If you clear DTC P0756, and then cannot reset DTC P0756, inspect for the following conditions:

    • Fluid contamination
    • Plugged oil circuits
    • Restricted oil circuits

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. This step verifies that the gear ratio is correct for the commanded gear.

    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 released.

    3.

  3. This step tests for a mechanical or hydraulic condition causing the 2-3 SS valve to be stuck ON, or the circuit to be applied.

DTC P0756 2-3 Shift Solenoid Valve -- Performance (2.4L and 3.1L)

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 2.4L or Powertrain On Board Diagnostic (OBD) System Check 3.1L

2

Was the Transmission Fluid Checking Procedure performed?

--

Go to Step 3

Go to Transmission Fluid Check

3

  1. Install the Scan Tool .
  2. 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. Using the Clear Info function erases the Freeze Frame and Failure Records from the PCM.

  3. Record the Freeze Frame and Failure Records.
  4. Clear the DTCs.
  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 3-4 shift with a TP greater than 8% and a vehicle speed greater than 8 km/h (5 mph) for 5 seconds.

Are the gear ratios within the given gear range?

1st: 2.87:1-3.13:1

4th: 0.61:1-0.72:1

Go to Diagnostic Aids

Go to Step 4

4

Does the engine labor at start-off, or is 4th gear indicated when 1st gear is commanded?

--

Go to Step 6

Go to Step 5

5

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

Is the repair complete?

--

Go to Step 7

--

6
  1. Inspect the 2-3 shift circuit for the following conditions:
    2. • 2-3 SS valve mechanically stuck ON
    • 2-3 SS valve stuck in the applied position
  2. Repair the circuit as necessary.

Is the repair complete?

--

Go to Step 7

--

7

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 0.75 seconds, for all gears.
  4. Select Specific DTC.
  5. Enter DTC P0756.

Has the test run and passed?

--

System OK

Go to Step 1