DTC P0756 2-3 Shift Solenoid Valve Performance. Buick Skylark 1998

For 1990-2009 cars only

Makes 🢒 Buick 🢒 1998 🢒 Skylark 🢒 DTC 🢒 DTC P0756 2-3 Shift Solenoid Valve Performance

DTC P0756 2-3 Shift Solenoid Valve Performance 2.4L Vin T

Automatic Transmission Components 2.4L
Automatic Transmission Controls Schematics 2.4L
OBD II Symbol Description Notice

Circuit Description

The 2-3 Shift Solenoid Valve (2-3 SS Valve) controls transmission fluid pressure on the 2-3 Shift Valve. Circuits 439/839 provide ignition voltage to the solenoid. When the PCM commands the solenoid OFF, filtered line pressure is exhausted at the solenoid. When the PCM commands the solenoid ON, the Output Driver Module (ODM), within the Powertrain Control Module (PCM), provides a ground, which energizes the solenoid. This causes the shift valve to move, closing the exhaust port and allowing line pressure to the hydraulic passage.

The PCM monitors the commanded gear and the speed ratio in order to identify a malfunction in the 2-3 Shift Solenoid Valve.

When the PCM detects a 1-2-2-1 or a 4-3-3-4 shift pattern, then DTC P0756 sets. DTC P0756 is a type A DTC.

Conditions for Setting the DTC

•	No TP DTCs P0122 or P0123.

•	No VSS DTCs P0502 or P0503.

•	No TCC solenoid Stuck On DTC P0742.

•	No solenoid electrical DTCs P0740, P0753, P0758 or P1860.

•	The engine speed is greater than 500 RPM for 5 seconds.

•	Not in fuel shut off.

•	The vehicle speed is greater than 26 km/h (16 mph).

•	Engine coolant temperature is 40-120°C (104-248°F).

•	The transmission range indicates D4.

All of the above must occur and one of the following fail conditions must occur:

•	Fail case 3 and 4 must occur twice (stuck on).

•	Fail case 1 and 3 or fail case 2 and 3 must occur three times (stuck off).

Case 1

•	The PCM commands first gear for more than 2 seconds.

•	The TCC slip speed is -4064 to -200 RPM.

•	Output speed is 800-1600 RPM.

•	The speed ratio is 0.76-3.0.

•	Throttle position is more than 35%.

•	All of the above occurs for more than 1.5 seconds.

Case 2

•	The PCM commands second gear for more than 2 seconds.

•	The TCC slip speed is -1000 to -200 RPM.

•	Output speed is 1000-2600 RPM.

•	The speed ratio is 1.1-1.6.

•	Throttle position is more than 18%.

•	All of the above occurs for more than 2.0 seconds.

Case 3

•	The PCM commands third gear for 2.5-7.5 seconds.

•	The TCC slip speed is 600 RPM more than the last slip speed in second gear.

•	The speed ratio is not 0.4 less than the last speed ratio in second gear.

•	Throttle position is 14-45% and constant by 7%.

•	All of the above occurs for more than 2.5 seconds.

Case 4

•	The PCM commands fourth gear for more than 1.0 second.

•	The TCC slip speed is 1600-6000 RPM.

•	Output speed is 1500-2800.

•	The speed ratio is 2-4.

•	Throttle position is more than 14%.

•	All of the above occurs for more than 1.5 seconds.

Action Taken When the DTC Sets

•	The PCM illuminates the Malfunction Indicator Lamp (MIL).

•	Transmission defaults to 3rd gear. The PCM inhibits TCC.

Conditions for Clearing the MIL/DTC

•	The PCM turns OFF the MIL after three consecutive trips 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.

•	The PCM cancels the DTC default actions when the fault no longer exists and the ignition is OFF long enough in order to power down the PCM.

Diagnostic Aids

•	Check for PRNDL DTC P0705. DTC P0705 affects transmission operation. This may set DTC P0756.

•	Inspect the transmission fluid for sediment.

•	Inspect the transmission filter for debris.

•	Ensure that the scan tool commanded gear has correct solenoid states and ratio. Refer to Shift Solenoid Valve State and Gear Ratio table.

Test Description

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

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

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

Step

Action

Value(s)

Yes

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

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

Have you performed the Transmission Fluid Checking Procedure?

Go to Step 3

Go to Transmission Fluid Check

Install the Scan Tool .
With the engine OFF, turn the ignition switch to the RUN position.

Important: Before clearing the DTCs, use the scan tool in order to record the Freeze Frame and Failure Records for reference. Using the Clear Info function will erase the stored Freeze Frame and Failure Records from the PCM.

Record the DTC Freeze Frame and Failure Records then clear the DTCs.
Inspect for the following conditions:

•	Shift solenoid screen assy. 374 for sediment or debris.

•	2-3 shift solenoid for a damaged or missing O-ring.

•	2-3 shift valve sticking, due to sediment, debris or damage.

Refer to Transmission Overhaul in the 4T60-E Section of the Transmission Unit Repair Manual.

Was a condition found and corrected?

Go to Step 5

Go to Step 4

Replace the 2-3 shift solenoid.

Refer to Solenoids and Wiring Harness Replacement.

Is the replacement complete

Go to Step 5

Perform the following procedure to verify your repair:

Use the scan tool to clear DTC information.
Operate the vehicle under the following conditions:

•	The engine speed is more than 500 RPM for 5 seconds.

•	The vehicle is not in fuel shut off.

•	Gear range is D4.

•	The engine coolant temperature is 40-120°C (104-248°F).

•	The vehicle speed is more than 26 km/h (16 mph).

•	All of the following pass criteria must be true:

Case 1

-	The PCM commands first gear for more than 2 seconds.

-	The throttle position is greater than 18%.

-	The speed ratio is 3.4-5.0.

-	The TCC slip speed is 200-2700 RPM.

-	The output speed is 800-1600 RPM.

-	All of these conditions occur for more than 1.5 seconds.

Case 2

-	The PCM commands fourth gear for more than 1 second.

-	The throttle position is more than 8%.

-	The speed ratio is 0.76-1.1.

-	The TCC slip speed is -20 to 100 RPM.

-	The output speed is 1500-2800 RPM.

-	All of these conditions occur for more than 3 seconds.

Select Specific DTC.
Enter DTC P0756.

Has the test run and passed?

System OK

Go to Step 1

DTC P0756 2-3 Shift Solenoid Valve Performance 3.1L Vin M

Automatic Transmission Components 3.1L
Automatic Transmission Controls Schematics 3.1L
OBD II Symbol Description Notice

Circuit Description

The 2-3 Shift Solenoid Valve (2-3 SS Valve) controls transmission fluid pressure on the 2-3 Shift Valve. Circuits 439/839 provide ignition voltage to the solenoid. When the PCM commands the solenoid OFF, filtered line pressure is exhausted at the solenoid. When the PCM commands the solenoid ON, the Output Driver Module (ODM) within the Powertrain Control Module (PCM) provides a ground which energizes the solenoid. This causes the shift valve to move, closing the exhaust port and allowing line pressure to the hydraulic passage.

The PCM monitors the commanded gear and the speed ratio to identify a malfunction in the 2-3 Shift Solenoid Valve.

When the PCM detects a 1-2-2-1 or a 4-3-3-4 shift pattern, then DTC P0756 sets. DTC P0756 is a type A DTC.

Conditions for Setting the DTC

•	No TP DTCs P0122 or P0123.

•	No VSS DTCs P0502 or P0503.

•	No TCC solenoid Stuck On DTC P0742.

•	No solenoid electrical DTCs P0740, P0753, P0758 or P1860.

•	The engine speed is greater than 500 RPM for 5 seconds.

•	Not in fuel shut off.

•	The vehicle speed is greater than 26 km/h (16 mph).

•	Transmission Fluid Temperature is 20-130°C (68-266°F).

•	The transmission range indicates D4.

All of the above must occur and one of the following fail conditions must occur:

•	Fail case 3 and 4 must occur three times (stuck on).

•	Fail case 1 and 3 or fail case 2 and 3 must occur three times (stuck off).

Case 1

•	The PCM commands first gear for more than 1.5 seconds.

•	The TCC slip speed is -4064 to -200 RPM.

•	Output speed is 900-1600 RPM.

•	The speed ratio is 0.6-2.3.

•	Throttle position is more than 35%.

•	Engine torque is 54-271 N·m (40-200 ft lbs).

•	All of the above occurs for more than 1.5 seconds.

Case 2

•	The PCM commands second gear for more than 2 seconds.

•	The TCC slip speed is -4064 to 0 RPM.

•	Output speed is 1000-2100 RPM.

•	The speed ratio is 0.97-1.45.

•	Throttle position is more than 18%.

•	Engine torque is 54-271 N·m 40-200 ft lbs).

•	All of the above occurs for more than 2.0 seconds.

Case 3

•	The PCM commands third gear for 2.5-7.5 seconds.

•	The TCC slip speed is 600 RPM more than the last slip speed in second gear.

•	The speed ratio is not 0.4 less than the last speed ratio in second gear.

•	Throttle position is 14-45% and constant by 7%.

•	Engine torque is 54-271 N·m 40-200 ft lbs).

•	All of the above occurs for more than 2.0 seconds.

Case 4

•	The PCM commands fourth gear for more than 1.0 second.

•	The TCC slip speed is 1600-6000 RPM.

•	Output speed is 1500-2800.

•	The speed ratio is 2-4.

•	Throttle position is more than 10%.

•	All of the above occurs for more than 1.5 seconds.

Action Taken When the DTC Sets

•	The PCM illuminates the Malfunction Indicator Lamp (MIL).

•	Transmission defaults to 3rd gear. The PCM inhibits TCC.

Conditions for Clearing the MIL/DTC

•	The PCM turns OFF the MIL after three consecutive trips 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.

•	The PCM cancels the DTC default actions when the fault no longer exists and the ignition is OFF long enough in order to power down the PCM.

Diagnostic Aids

•	Check for PRNDL DTC P0705. DTC P0705 affects transmission operation. This may set DTC P0756.

•	Inspect the transmission fluid for sediment.

•	Inspect the transmission filter for debris.

•	Ensure that the scan tool commanded gear has correct solenoid states and ratio. Refer to Shift Solenoid Valve State and Gear Ratio table.

Test Description

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

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

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

Step

Action

Value(s)

Yes

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

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

Have you performed the Transmission Fluid Checking Procedure?

Go to Step 3

Go to Transmission Fluid Check

Install the Scan Tool .
With the engine OFF, turn the ignition switch to the RUN position.

Record the DTC Freeze Frame and Failure Records then clear the DTCs.
Inspect for the following conditions:

•	Shift solenoid screen assy. 374 for sediment or debris.

•	2-3 shift solenoid for a damaged or missing O-ring.

Refer to Transmission Overhaul in the 4T60-E Section of the Transmission Unit Repair Manual.

Was a condition found and corrected?

Go to Step 5

Go to Step 4

Replace the 2-3 shift solenoid.

Refer to Solenoids and Wiring Harness Replacement.

Is the replacement complete?

Go to Step 5

Perform the following procedure to verify your repair:

Use the scan tool to clear DTC information.
Operate the vehicle under the following conditions:

•	The engine speed is more than 500 RPM for 5 seconds.

•	The vehicle is not in fuel shut off.

•	Gear range is D4.

•	The transmission fluid temperature is 20-130°C (68-268°F).

•	The vehicle speed is more than 26 km/h (16 mph).

•	Engine torque is 54-271 N·m (40-200 ft lbs).

•	All of the following pass criteria must be true:

Case 1

-	The PCM commands first gear for more than 1.5 seconds.

-	The throttle position is greater than 18%.

-	The speed ratio is 2.7-4.0.

-	The TCC slip speed is 200-2700 RPM.

-	The output speed is 900-1600 RPM.

-	All of these conditions occur for more than 1.5 seconds.

Case 2

-	The PCM commands fourth gear for more than 1.0 second.

-	The throttle position is more than 14%.

-	The speed ratio is 0.58-0.88.

-	The TCC slip speed is -20 to 100 RPM.

-	The output speed is 1500-2800 RPM.

-	All of these conditions occur for more than 3 seconds.

Select Specific DTC.
Enter DTC P0756.

Has the test run and passed?

System OK

Go to Step 1