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Discussion Starter #1
Eric,


Can my larger transmission cooler, turned 90* to the OEM cause the transmission to "vapor" lock or something? It was like there was no flow. The codes were 700 and 747. My transmission has always seemed to run hot and has slipped with no power adder at around 220 degrees on the dash gauge. That is why I put on the larger cooler. I used 5/8" hose and fittings and even retained the OEM quick disconnects, which appear to be the smallest point of the system. I had the line from the radiator going into the bottom, pushing fluid up the cooler and coming out the top to return to the transmission. Do I need to revearse that or wait for my fittings to get made to have it in the same orientation.



I REALLY wish you weren't 1000 miles away.



PS - Got my stuff the other day. Thanks.
 

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Chris, the 747 code is the "a" trim solenoid. this will cause your no move. I will attatch the diagnostics below for that code. the 700 code is just a code in the pcm to indicate stored codes in the tcm. I dont think your cooler has anything to do with it. Sounds like you have other issues going on it that tranny.
<H1>DTC P0747</H1>


<A name=ss1-787392><A href="http://service.gm.com/servlets/BlobShtml?ShtmlFile=787392&psdid=271&evc=sm#ss1-787392" target="_blank">
<H5>Circuit Description</A></H5>



<H4>Important</H4>


DTC P0747 was previously P1723.





Trim solenoid A is used to control on-coming, off-going and holding pressure in 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 solenoid A will vary depending on the shift being made.


DTC P0747 is a type A DTC.<A name=ss2-787392><A href="http://service.gm.com/servlets/BlobShtml?ShtmlFile=787392&psdid=271&evc=sm#ss2-787392" target="_blank">
<H5>Conditions for Running the DTC</A></H5>
<UL =BULLET>
<LI>Components are powered and ignition voltage is greater than 9 V and less than 18 V.
<LI>One of the following conditions occurs:
<UL =SQUARE>
<LI>Output speed is greater than 200 RPM.
<LI>Turbine speed is greater than 200 RPM. </LI>[/list]</LI>[/list]<A name=ss3-787392><A href="http://service.gm.com/servlets/BlobShtml?ShtmlFile=787392&psdid=271&evc=sm#ss3-787392" target="_blank">
<H5>Conditions for Setting the DTC</A></H5>


DTC P0747 sets when the TCM detects an incorrect off-going ratio, forward-range-to-forward-range, for an accumulated number of occurrences during one ignition cycle.<A name=ss4-787392><A href="http://service.gm.com/servlets/BlobShtml?ShtmlFile=787392&psdid=271&evc=sm#ss4-787392" target="_blank">
<H5>Action Taken When the DTC Sets</A></H5>
<UL =BULLET>
<LI>The TCM illuminates the Malfunction Indicator Lamp (MIL).
<LI>If failure occurs in a forward range, the transmission will go to the previous range.
<LI>If failure occurs in neutral or reverse, the transmission will lock in NEUTRAL while diagnostic response is active.
<LI>If the shift selector is moved to NEUTRAL, the transmission will shift to NEUTRAL.
<LI>If the shift selector is moved to REVERSE, the transmission will shift to REVERSE or NEUTRAL or in some cases may lock in NEUTRAL.
<LI>If the shift selector is returned to a forward range and the transmission is compromised by overspeeding or direction change, the transmission will shift to NEUTRAL.
<LI>DTC P0747 will be stored in the TCM history.
<LI>The TCM freezes shift adapts.
<LI>TCM inhibits Torque Converter Clutch (TCC) engagement. </LI>[/list]<A name=ss5-787392><A href="http://service.gm.com/servlets/BlobShtml?ShtmlFile=787392&psdid=271&evc=sm#ss5-787392" target="_blank">
<H5>Conditions for Clearing the MIL/DTC</A></H5>


A Scan Tool can clear the code from the TCM history. The TCM automatically clears the DTC from the TCM history if the vehicle completes 40 warm-up cycles without failure.<A name=ss6-787392><A href="http://service.gm.com/servlets/BlobShtml?ShtmlFile=787392&psdid=271&evc=sm#ss6-787392" target="_blank">
<H5>Diagnostic Aids</A></H5>
<UL =BULLET>
<LI>Inspect the wiring for poor electrical connections at the TCM. Look for the following conditions:
<UL =SQUARE>
<LI>A bent terminal.
<LI>A backed-out terminal.
<LI>A damaged terminal.
<LI>Poor terminal tension.
<LI>A chafed wire.
<LI>A broken wire inside the insulation. </LI>[/list]
<LI>When diagnosing for an intermittent short or open, massage the wiring harness while watching the test equipment
 

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Discussion Starter #3
Eric,


Thanks a million. I guess in she goes.


Chris
 

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Discussion Starter #4
My dealer said he can't look at it until Monday. Is there any risk driving it? Should I take the wife's truck on our trip this weekend? Is there anyway to get the solinoid to work if it does it again?
 

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I would be leary on driving it if it acts up and wont 'clear' itself with cycyling the key, I would hate to see you stranded. Other then that, no risk
 

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Discussion Starter #6
I guess we will take the wife's furd.
That just KILLS me,
but getting stranded on the side of the road on her birthday might get me a divorce or worse.
 
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