Howell Engineering LT4 harness not working

[calvin]

Hi guys. Got an issue with a harness I purchased form my LT4 swap.

I called howell engineering and told them what I was building. LT4/4l80e swap into a 56' pickup.

The guy there said no problem, we'll build you a harness and ecu for your application. You'll just need to get a stand alone TCM.

Fast forward to this month. We got everything installed and the engine has about 25% power. Got a tuner involved and he logged into the ECU and said it's in limp mode and it looks like it's due to no VSS sensor signal.

Call Howell and they say " gee..yeah, not really sure what's happening as we've never built one for a SC application". So now i'm paying a couple guys to try and do their R/D to find a work around. Needless to say i'm pissed, I would have never bought this crap if I had known I was the guinea pig.


Anyone ever run across this issue doing this swap. Did you find a VSS work around or figure out how to properly pin in an old 2 wire VSS instead of a 3 wire?



Thanks for any help

[dhutton]

I am not sure if your case is the same but I have used this with good results. Sorry if I misunderstood.

https://www.amazon.com/Michigan-Moto...OUK533GU&gQT=1

[calvin]

Thanks. I don't think so though. It has to go from the new style 3 wire VSS that was mated to the LT4 (like the 6l90e) and back to the 2 wire for the 4l80 :(

[dhutton]

Pretty sure I used it to convert a two wire VSS sender to connect to an ECM looking for a three wire signal. It has been a while though.

[Vimes]

How about a 3 wire VSS for the 4L80E? The description says it's for using a 4L80E (amongst others) behind an LT1. You'll definitely want to discuss it with them before buying.

https://bp-automotive.com/product/t5...al-3-wire-vss/

[ween]

Possibly this: https://sirhclabs.com/product/cortex...ensor-adapter/
but of course not in stock. But I do have one.

[calvin]

Thank you guys. We seem to have found a schematic and pinned a connector in there after figuring out what ground it wanted to see.

Now on to the next issue lol