Transmission code P0747

[Chevy366]

Man just got my TransGo kit installed and took the truck for a spin and got a orange engine light , went by Auotzone ran code and came up with P0747 , something about a high pressure solenoid valve stuck open .
I was very careful and made sure everything was clean and checked every move I made 3 times or more .
Truck shifts through all the gears except overdrive , has anyone else seen or heard of this happening ?

[RedHeartbeat]

Sounds like a solenoid didn't get hooked up correctly. I've never had any code like that before. P0757, yes, but that's to do with a huge stall.

[bluecajun5.3]

<div class='quotetop'>QUOTE(RedHeartbeat &#064; Jun 11 2006, 10&#58;12 AM) [snapback]55185[/snapback]</div>

Sounds like a solenoid didn&#39;t get hooked up correctly. I&#39;ve never had any code like that before. P0757, yes, but that&#39;s to do with a huge stall.
[/b]

correct. i&#39;ve had that code pop up once or twice.

[Bowtie70SS]

I did a shift kit install and got P0748...some dumbass(me) forgot to hook up the pressure solenoid. Also you need to torque the valve body bolts in a circle from inside towards the outside to keep from distorting it and binding something (per GM service manual).

Dave

[Chevy366]

I could not stand it , so I took the pan back off the trans ,(drain plug was a god send) , nothing all was well , that is all wires hooked up correctly , even went as far as to pull the valve body off again just to check the check balls , all were it right places , I think it is the tune doing it , to much line pressure .
Going to call TranGo and see what they say , I did notice that reverse hits real hard and I mean real hard , it jerks the truck when u put it in R , at low idle after engine warm up .

[Bowtie70SS]

That jerking is a sure sign of high line pressure. Mine did that with the pressure solenoid unhooked, now it&#39;s normal. If you had a previous tune with jacked line pressure you need to have the pressures returned to stock as the shift kit will raise the pressures for you.

Dave

[Chevy366]

<div class='quotetop'>QUOTE(Bowtie70SS &#064; Jun 12 2006, 05&#58;49 PM) [snapback]55290[/snapback]</div>

That jerking is a sure sign of high line pressure. Mine did that with the pressure solenoid unhooked, now it&#39;s normal. If you had a previous tune with jacked line pressure you need to have the pressures returned to stock as the shift kit will raise the pressures for you.

Dave
[/b]

That is what I thought , RedHeartBeat must have jinxed me , put it all back together and drove it again got a different code this time P0757 ( thanks Red ) , so what is the fix for the P0757 code ?
This time and last it seemed as if it did not go into overdrive , could hit the tow/haul button and would drop a gear but still not sure if overdrive is working right .

Thanks in advance .

[Bowtie70SS]

Here is the info out of the GM techline CD

DTC P0747
Circuit Description
Pressure control (PC) solenoid A is used to control oncoming, off-going, and holding pressure to any one of the five clutches. This solenoid is referred to as a pressure proportional to current (PPC) solenoid since the output hydraulic pressure supplied by this solenoid is proportional to the controlled current command.

The transmission control module (TCM) uses information from the turbine and output speed sensors to detect if a clutch is in a tie-up condition or 3 clutches are applied. The clutch being controlled by PC solenoid A will vary depending on the shift being made.

DTC P0747 is a type A DTC.

DTC Descriptor
This diagnostic procedure supports the following DTC:

DTC P0747 Pressure Solenoid A Stuck On

Conditions for Running the DTC
• DTCs P0716, P0717, P0721, P0722, P0875, and P0876 are not active.
• The components are powered and ignition voltage is greater than 9.0 volts and less than 18 volts.
• Output speed is greater than 200 RPM.
• Turbine speed is greater than 200 RPM.

Conditions for Setting the DTC
DTC P0747 sets if the TCM determines off-going clutch controlled by PC solenoid A remains engaged during a forward range shift.

Action Taken When the DTC Sets
• The TCM illuminates the malfunction indicator lamp (MIL).
• When failure occurs in a forward range, the transmission will go to the previous range. If failure occurs in NEUTRAL or REVERSE, the transmission will lock in NEUTRAL while diagnostic response is active.
• If the shift selector is moved to NEUTRAL, the transmission will shift to NEUTRAL.
• If the shift selector is moved to REVERSE, the transmission will shift to REVERSE or NEUTRAL, or in some cases may lock in NEUTRAL.
• If the shift selector is returned to a forward range and the transmission is compromised by over speeding or direction change, the transmission will shift to NEUTRAL.
• DTC P0747 will be stored in TCM history.
• The TCM freezes shift adapts.
• The TCM inhibits torque converter clutch (TCC) engagement.

Conditions for Clearing the DTC
A scan tool can clear the code from TCM history. The TCM automatically clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without failure.

Diagnostic Aids
• Inspect the wiring for poor electrical connections at the TCM. Inspect for the following conditions:
• A bent terminal
• A backed-out terminal
• A damaged terminal
• Poor terminal tension
• A chafed wire
• A broken wire inside the insulation
• When diagnosing for an intermittent short or open, massage the wiring harness while watching the test equipment for a change.
• You may have to drive the vehicle in order to experience a condition.
• This DTC indicates the off-going clutch being controlled by PC solenoid A, is not releasing or is slow to release. This could indicate a leak or obstruction in a specific clutch apply circuit. Observe scan tool failure record data for previous or current range information when the DTC was set, to determine the specific shift when the DTC was set. Refer to Solenoid and Clutch Chart to determine which clutch circuit is suspect.
• Important: Clutch failure due to installation of an engine power upgrade is not covered under the manufacturers warranty.


Inspect for the presence of an add-on engine power package. When engine horsepower or torque is increased over factory rating, a shift flare condition may occur.

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

This step tests for proper ignition voltage.

This step tests for erratic speed sensor readings.

This step tests for internal hydraulic leakage.

This step tests for clutch capacity.

Step
Action
Value
Yes
No

Schematic Reference: Automatic Transmission Controls Schematics

1
Did you perform the Diagnostic System Check - Vehicle?
--
Go to Step 2
Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2
Measure the transmission fluid level. Refer to Transmission Fluid Checking Procedure .

Is the transmission fluid level correct?
--
Go to Step 3
Go to Transmission Fluid Checking Procedure

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


Record the DTC Freeze Frame and Failure Records.
Clear the DTC.
Using the scan tool, measure ignition voltage.
Is the voltage within the specified range?
9-18 V
Go to Step 4
Go to DTC P0562 for low voltage or DTC P0563 for high voltage

4
Start the engine.
Drive the vehicle under normal operating conditions.
Using the scan tool, monitor engine, turbine, and output speed sensor readings.
Is speed sensor data erratic?
--
Go to the appropriate speed sensor DTC
Go to Step 5

5
Connect a 2,000 kPa (300 psi) pressure gage to the line pressure tap. Refer to Line Pressure Check Procedure .
Use the scan tool, in clutch test mode, to cycle through all transmission ranges with the engine at idle and vehicle brakes applied. Record line pressure in each range.
Was the line pressure low in a specific range or in ranges where the same clutch was applied?
--
Go to Low Main Line Pressure in All Ranges
Go to Step 6

6
Refer to Transmission Stall Test Notice in Cautions and Notices.

Conduct a clutch test for all forward ranges. Refer to Clutch Test .

Did turbine speed remain at zero in all ranges?
--
Go to Diagnostic Aids
Go to Step 7

7
Remove the transmission oil pan. Refer to Automatic Transmission Fluid/Filter Replacement .
Inspect for signs of clutch failure.
Are there signs of a clutch failure?
--
Go to Step 8
Go to Step 9

8
Remove the transmission for overhaul or replacement. Refer to Transmission Replacement .

Did you complete the repair or replacement?
--
Go to Step 11
--

9
Inspect for a stuck or sticking PC valve. Refer to Control Valve Body Cleaning and Inspection .

Did you find and repair a condition?
--
Go to Step 11
Go to Step 10

10
Replace PC solenoid A. Refer to Control Valve Solenoid Replacement .

Did you complete the replacement?
--
Go to Step 11
--

11
Perform the following procedure in order to verify the repair:

Clear the DTC.
Start the engine.
Use the scan tool to reset adaptive values for all shifts.
Operate the vehicle in all ranges under normal driving conditions.
Select Specific DTC.
Enter DTC P0747.
Has test run and passed?
System OK
Go to Step 1



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Document ID# 1492353
2005 Chevrolet Chevy C Silverado - 2WD


Dave

[Chevy366]

Wow , great info there , don&#39;t happen to have anything on DTC P0757 to ?
I think it has to do with solenoid B 2-3 shift stuck on ?
The truck ran fine at first today drove about 2 miles and slowed down to make a trun around and the light came on again .
I borrowed a code reader from a friend ( Thanks COWL327) and read the code P0757 , so bad solenoid or just trash in the valve or to much fluid pressure ?

Thanks

[COWL327]

<div class='quotetop'>QUOTE(use2bfo &#064; Jun 12 2006, 09&#58;20 PM) [snapback]55307[/snapback]</div>

Wow , great info there , don&#39;t happen to have anything on DTC P0757 to ?
I think it has to do with solenoid B 2-3 shift stuck on ?
The truck ran fine at first today drove about 2 miles and slowed down to make a trun around and the light came on again .
I borrowed a code reader from a friend ( Thanks COWL327) and read the code P0757 , so bad solenoid or just trash in the valve or to much fluid pressure ?

Thanks
[/b]

Any time dude...Youve helped me plenty of times.Except that ie beta ......LOL just,,,,, fuckin with ya.&#33;Its fixed and he fixed it......NEXT&#33;&#33;&#33;&#33;