Have a 5 OHM resistor in the pan, coming off the C and D connectors that used to read the Pressure Control Solenoid. I'm getting DTC P0748 and its preventing shift adapts and a 2-3 at WOT. Has anyone here gone vacuum modualted and had this problem?

 

Mine has the code also. It seems to shift perfect though I have a Yank 4L60E. The code is for a bad solenoid right?

One of my buddies cars had the same problem but his trans blew up before we could check out the problem. We originally thought it was a batch of bad resistors. When did you buy your kit? And from who?

 

hmm...maybe the resister is faulty

i've installed a few of them when i worked at a trans shop and none of them threw a code

the only thing i think would throw a code is if that resister isn't correct

 

Yes. I have double-checked both the resistance
(5 ohm) and connection. If you want to have some fun you might try a DIFFERENT resistor as that one does not seem to be exactly what the LS1 PCM likes to see.

That is a SOFT code, though (does not set check engine light, at least on my car) nor does it cause any shifting malfunction.

 

I have a vacuum modulator kit in mine, but I honestly don't think we installed a resistor of any sort in the tranny, or anywhere else. Mine shfts fine and no codes.

Tim

 

Thanks for the replies guys. We took the eng/trans wire harness out of the loop by cutting the wires by the PCM and putting in different resistors. We tried 5 Ohm and 4.5 Ohm but neither worked. Finally ended up putting a Pressure Control Solenoid (VERY tired of dropping the pan and wasting money on fluid) up by the PCM and the code went away. Unfortunately the 2-3 shift at WOT still isnt happening. I really was hoping it was related to the code!! <img border="0" title="" alt="[Sad]" src="gr_sad.gif" /> <img border="0" title="" alt="[Sad]" src="gr_sad.gif" /> Oh well the troubleshooting continues....

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Chris99WS6PWTMET:
<strong> Unfortunately the 2-3 shift at WOT still isnt happening. I really was hoping it was related to the code!! <img border="0" title="" alt="[Sad]" src="gr_sad.gif" /> <img border="0" title="" alt="[Sad]" src="gr_sad.gif" /> Oh well the troubleshooting continues....</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Mine never did make the 2-3 shift at WOT after the vacuum kit install and the tranny blew 2 days after, under normal driving conditions. I had the code as well.

 

Why are ya'll putting resistors in the pan and/or by the PCM? Mine works perfect without all that crap. My vacuum modulator makes ALL my shifts firm and quick.

Tim

 

It's an o-ring resistor and yours has it as well or you are running around town with a flashing ses light. Either that or you had the code removed with custom pcm programming. It's part of the kit.