The 2-3 shift solenoid (SS) valve controls fluid flow
acting on the 2-3 shift valves. The 2-3 SS valve
is a normally-open exhaust valve used with the
1-2 SS valve in order to allow for four different
shift combinations.
When the powertrain control module (PCM) detects a 4-3-3-4
gear ratio, then DTC P0756 sets. DTC P0756 is a type C DTC.
For California emissions vehicles and vehicles under 8,600 GVW,
DTC P0756 is a type A DTC.
The numbers below refer to the step numbers on the diagnostic table.
Step
| Action
| Value(s)
| Yes
| No
|
1
| Did you perform the Diagnostic System Check - Engine Controls?
| --
| Go to
Step 2
| Go to
Diagnostic System Check - Engine Controls
in Engine Controls - 6.0L
|
2
|
- Install a scan tool.
- Turn ON the ignition, with the engine OFF.
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.
- Record the Freeze Frame and Failure Records.
- Clear the DTCs.
- Select TFP switch A/B/C on the scan tool.
- With the engine running, apply the brake pedal and select each
transmission range: D1, D2, D3, D4, N, R, and P.
Refer to
Transmission Fluid Pressure Manual Valve Position Switch Logic
.
Does each selected transmission range match the scan tool TFP switch A/B/C display?
| --
| Go to
Step 3
| Go to
DTC P1810
|
3
|
- Raise and support the drive axle assembly.
- Start the engine.
- With the transmission in the D4 range, use the scan tool in order
to command 1st, 2nd, 3rd, and 4th gears while accelerating the vehicle.
The vehicle may need to be road tested.
Was 1st gear commanded and not achieved, or 4th gear commanded and
another gear occurred?
| --
| Go to
Step 4
| Go to Diagnostic Aids
|
4
|
- Inspect the transmission for the following conditions:
• | 2-3 shift solenoid mechanically stuck ON |
• | 2-3 shift valve stuck in the applied position |
• | Damaged 2-3 shift solenoid seals |
- Repair the circuit as necessary.
Did you complete the repair?
| --
| Go to
Step 5
| --
|
5
| Perform the following
procedure in order to verify the repair:
- Select DTC.
- Select Clear Info.
- Operate the vehicle under the following conditions, only if traffic
conditions permit:
• | The PCM must see the proper gear ratio for each gear for greater
than one second in D1, D2, D3, and D4. |
• | Accelerate the vehicle with the throttle angle greater than 7 percent
up to 89 km/h (55 mph). |
- Select Specific DTC.
- Enter DTC P0756.
Has the test run and passed?
| --
| Go to
Step
6
| Go to
Step
2
|
6
| With the scan tool, observe the stored information, capture info and DTC info.
Does the scan tool display any DTCs that you have not diagnosed?
| --
| Go to
Diagnostic Trouble Code (DTC) List
in Engine Controls - 6.0L
| System OK
|