5.3L Vortec Truck Switch from NV4500 to 4L60 Harness Question (1 Viewer)

[meatloaf]

I have working on bringing my 60 back to life for the last couple of years... Due to issues with the front retainer breaking H55 (3X), I sold the H55 and bought an '02 NV4500 off Craigslist and ordered the TC adapter from AA & new Aisin clutch. I mated everything together and have never ran this combo since truck has other issues I am also working on. Due to my left knee being old and in constant pain, I am considering selling the manual tranny/adapters and going with a 4L60 auto. Can I just add the wire(s) to the harness for the auto or will I need a completely new harness? I know computer will need to be reflashed... The harness I have came from Fuel Injection Specialties which I recently had to rebuild due to a pyro-accident which melted the injector wires. Trying to save some $$ if possible.

 

[Shes Mad]

I would call fuel injection specialties. The plug to the trans is pretty big with a lot of wires, and you have to reflash the computer anyway.

 

[meatloaf]

Fuel Injection Specialties customer service sucks. I have called them 3X in the last year and each time, they were supposed to call me right back, still waiting.

 

[MANUCHAO]

Probably what you don't want to hear..... but best thing to do is get a new harness altogether, and reflash the pcm...

 

[workingdog]

I have the same question. I'm planning on going from NV4500 to 4L60. I'm hoping I can send the harness back to Howell and have them add the necessary wires. You can do it, but it requires add all the right pins to the ECM connectors and I don't have the patience.

 

[workingdog]

It is my understanding (from limited experience) that the flash is really simple.

 

[spotcruiser]

Brendan at LT1Swap has a lot of good info on his site. He's also extremely reasonable for ECM reprogramming. You can see what wiring is necessary here:

Wiring Harness Information

 

[workingdog]

Yes, to use HP tuners, you'll have to pay the fee. But there's not tuning required to re-enable the automatic (or remove the VATS - but I assume that's already been done, if not, there's quite a few things that have to be done to the tune to make it run without the rest of the Chevy it was born in.

 

[meatloaf]

Probably what you don't want to hear..... but best thing to do is get a new harness altogether, and reflash the pcm...

Yes Manu, I am just in denial...

It isn't too big of a deal to add the trans harness in. I want to say it is 15 wires worth. Not too big of a deal but you can end up with a 'mess' at the PCM. I'm doing this on one of the 55s.

I forget the split of 4l60s but they have different harnesses and I can't tell you the compatibility between years. Best bet to get same year tranny and harness as your pcm.

Yes, you do have to flash the PCM. The tunes are not compatible either way. Ran into this issue on my green 55 :/

Brendan at LT1Swap has a lot of good info on his site. He's also extremely reasonable for ECM reprogramming. You can see what wiring is necessary here:

Wiring Harness Information

I used LT1Swap site to check & double-check pins on my current harness after the meltdown. Great site!

In and of itself, it isn't too bad. I've 'flashed' with a Jet DST tuner on my 6.0L to get it limping(remove VATS and put a faked up manual tune). While I haven't flashed with the HP Tuner, I've got it on the shelf. It is all tweaking that takes time.

The cost comes from the per vehicle licensing. DST was ~$100 per vehicle. HP is roughly the same but then they start adding in model/year/generation 'breaks'. I want to say Gen III LSs were ~130 credits... credits were ~$50 each.

Last I checked, tuning shops charged $100 for removing things like VATs and other codes.

There a local guy advertising on CL, he charges $100 per vehicle flashing

 

[workingdog]

I'm curious about the fuel/spark tables that are different - can you be specific?

 

[workingdog]

Whenever it's easy, if you could let me know what tables you had to change, I'd appreciate it.

 

[Elbert]

If the harness you presently have...has no setup for auto transmission, then I would predict you need the correct harness to interact with the auto transmission (new harness overall all) My old engine harness (painless) has the auto transmission setup already in the harness, for now I don't use that as I have the h55 (I just have the auto transmission jumper of the engine harness tied off). With manual transmission there is no connection other than neutral/safety switch (if the harness supports that). First order of business would be to see what options your engine harness has built in. My setup is a 5.7 vortec.

Conceptually I potentially could add the necessary wiring but tha'ts likley to be a royal pain in the @ass I would suspect. You also need to control the lockup torque converter.

I understand some of the automatic transmissions require their own controller (computer)....they don't run of the primary ECM.

Sounds like you would need the ECM reprogrammed, potentially you might need the transmission controller also depending on which engine and transmission combination you have and then you likely will need entire new engine harness.

I'm thinking of jumping off on the same thing at some point....but if do, depending on funds I'll likley just get a 5.3 or 6.0 with matching transmission to swap everything.