sleeperlqx

iTrader: (3)

okay so here is the deal, the truck is still stuck in limp mode. At first I would have a delay to engage, now its just delays, and goes straight to 2 on the gear selector on the cluster. No matter what forward gear it goes to 2 and just revs... I have to turn the truck OFF, for it to act normal, and drive for about 1 min. I notice on morning it will run fine for 2-3 mins before it gets warmed up. Then Ill have to turn it off and limp it again.

Truck is a 01 Tahoe with a 4l80e swapped. method using the relay single no pmw. I even replaced the relay, went over and rewired and verified it was correct, and soldered all connections up properly.

truck still does the same limp mode problem. I doubt its the tranny fluid is full, smells good, and it hauls *** when I get it to run after the restarting.

I even went ahead and replaced both front 02 sensors with new ones today, truck runs better, but same problem with limp mode.

The TPS sensor in the truck is about 2 -3 months old, doubt its bad.

I have not changed the VSS yet in the tail of the tranny cause my speedo still works, but Ill try swap them and see..

Other than that Im at wits end. WTF could it be?

UnVmy5.3

You have to have a few codes deleted

sleeperlqx

iTrader: (3)

lol, I did, its been street tuned by a professional, drove fine for 2 years after that.

BlackGMC

iTrader: (31)

when you do the relay mod you need to delete a few more codes on the tranny side so the tests never run..... i forgot which ones but the tests/codes must be deleted inorder to run the relay mod.... That is probably your problems

sleeperlqx

iTrader: (3)

It was, it has, unless my PCM retuned it self, it should still retain the deletion of all trans related codes. It was like 4 parameters he removed.

Quote:

Originally Posted by sleeperlqx

lol, I did, its been street tuned by a professional, drove fine for 2 years after that.

Yea, trucks been JUST FINE for 2 years.... I went I recheck everything and it was fine, and still is. just stomped. I got the Fluke out the closet today, and going to investigate deeper. I think I burnt up some wires somewhere. and Im not sure if it was internally.

Im not sure if a failing MAF sensor put it into limp mode? I replaced a VSS with a spear I had last night, and the truck ran better, untill I made it out the garage then acted up again. So had to restart it, and drive it back inside.

sleeperlqx

iTrader: (3)

are you suggesting, my PCM flashed itself somehow, and lost programing? or maybe my PCM is fried at this point and lost everything? which I doubt cause my engine sitll hauls *** when not in limp. I almost did a burnout in reverse.

sleeperlqx

iTrader: (3)

I verified good voltage at tranny harness. good ground as well. both at relay as well. So the problem has to be tranny or pcm. Truck has same symptoms as before. Once warmed up for about 1 min it goes into limp mode gear selector switches to 2 automatically, and truck just free revs, in Drive and Reverse. But turn the truck off, and all Rev, and drive is back. The Gear selector when switched to D or 1 does not illuminate either, if I start moving, driving in Drive then the D will illuminate.

sleeperlqx

iTrader: (3)

So I unplugged the harness, and placed the truck in reverse and drive, and It works untill warmed up as usual. Then both reverse and 2nd gear went out. Till I restarted it.

Has to be the transmission right? no electrical was hooked up except the neutral saftey switch.


Looks like its time for a new converter and tranny.

slow67

iTrader: (2)

Yes, it should have reverse and 2nd gear with teh transmission unplugged.

sleeperlqx

iTrader: (3)

thanks for the confirmation... pulling that sucker in a few mins, should be out this weekend.