DTC P0756 2-3 Shift Solenoid Valve Performance. Pontiac Sunfire 1997

For 1990-2009 cars only

Makes 🢒 Pontiac 🢒 1997 🢒 Sunfire 🢒 Transmission/Transaxle 🢒 Automatic Transaxle - 4T40-E 🢒 DTC P0756 2-3 Shift Solenoid Valve Performance

Table 1:	Shift Solenoid State Table
Table 2:	DTC P0756 2-3 Shift Solenoid Valve (2-3 SS Valve) -- Performance

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.

The Powertrain Control Module (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 Setting the DTC

•	No TP Sensor DTCs P0121, P0122 or P0123.

•	No A/T OSS 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 Val. Position Sw. DTC P1810.

•	The engine is running.

•	The TFP Val. Position Sw. indicates D4, D3, D2 or D1.

•	The vehicle speed is greater than 8 km/h (5 mph).

•	The TP is greater than 8%.

•	Engine torque is greater than 19N·m (15 lb. ft.).

•	The MAP is greater than 20 kPa.

•	The transmission fluid temperature is greater than -10°C (14°F).

•	All of the above conditions are true, and any one of the following fail cases occurs:

Case 1

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

•	The PCM commands 2nd gear and the gear ratio is 1:0.91-1:1.07 (3rd gear) for 5 seconds.

Case 2

•	The PCM commands 3rd gear and the gear ratio is 1:1.54-1:1.71 (2nd gear) for 5 seconds.

•	The PCM commands 4th gear and the gear ratio is 1:2.87-1:3.13 (1st gear) for 5 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.

•	DTC P0756 is stored in the PCM history.

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

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

-	Fluid contamination

-	Plugged oil circuits

-	Restricted oil circuits

Shift Solenoid State Table

Gear	1-2 Shift Solenoid Valve	2-3 Shift Solenoid Valve
1st	ON	OFF
2nd	OFF	OFF
3rd	OFF	ON
4th	ON	ON

Test Description

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

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

This step tests for a mechanical or hydraulic problem causing the 2-3 SS valve to be stuck OFF, or the circuit to be released.

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

DTC P0756 2-3 Shift Solenoid Valve (2-3 SS Valve) -- Performance

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 DTC(s), 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 DTC(s).
Use the scan tool snapshot mode in order to record current gear and gear ratio.
Drive the vehicle in D4, in order to obtain a 2-3 shift with a TP greater than 8% and a vehicle speed greater than 8 km/h (5 mph) for 6 seconds.

Are the gear ratios within the given gear range?

1st: 2.87-3.13

4th: 0.61-0.72

Go to Diagnostic Aids

Go to Step 4

Does the engine labor at start-off, or is 3rd gear indicated when 1st gear is commanded?

Go to Step 6

Go to Step 5

Inspect the 2-3 shift circuit for the following conditions:

•	2-3 Shift Solenoid Valve (2-3 SS Valve) mechanically stuck OFF.

•	Damaged 2-3 SS Valve O-ring

•	2-3 SS Valve stuck in the released position.

Repair the circuit.

Refer to Unit Repair.

Did you find and correct the condition?

Go to Step 7

Inspect the 2-3 shift circuit for the following conditions:

•	2-3 SS Valve mechanically stuck ON.

•	2-3 SS Valve stuck in the applied position.

Repair the circuit.

Refer to Unit Repair.

Did you find and correct the condition?

Go to Step 7

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

Select DTC.
Select Clear Info.
Operate the vehicle under the following conditions:

•	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 3 seconds, for all gears.

Select Specific DTC. Enter DTC P0756.

Has the test run and passed?

System OK

Begin the diagnosis again. Go to Step 1