Ls swap vss

The Luke · Feb 19, 2019

I'm finishing up cutting down a 5.3 harness and ran into a speed bump on the vss.

I've googled and found about 9,000 answers. No clue what's the right one.

5.3/th350/207(I know, I know)

I know the 5.3 needs to see a pulsing signal from the vss. But the th350 runs a mechanical sensor. The 207 has an electrical output. I'm wondering if the number of pulses can be reprogrammed to work off the stock 207 sensor or if I need to find another option. What have y'all done? What worked and what didn't?

RustyC · Feb 19, 2019

Yes the ecm can be tuned to the 207 speed sensor. It is the same as recalibrating for regearing a rear axle or tire size change.
I also run a 5.3/ th350 combo with a 205. I used a speed sensor from a mustang in the original 205 location. No stalling or idle issues at all.

The Luke · Feb 19, 2019

Well, I lied. Just found out the 207 is a mechanical output. Sorry about that

onetoncrawler · Feb 19, 2019

RustyC said:
Yes the ecm can be tuned to the 207 speed sensor. It is the same as recalibrating for regearing a rear axle or tire size change.
I also run a 5.3/ th350 combo with a 205. I used a speed sensor from a mustang in the original 205 location. No stalling or idle issues at all.

I have never used a VSS with a 5.3 and multiple 6.0 builds. I've always ran manual valve bodies and either a 205 or atlas case with no wiring to either. Granted, knowing what I know now I believe the engine would react better with one if you can make it work. But my point was it shouldn't be an absolute necessity. Not that I'm aware of anyways. :dblthumb:

RustyC · Feb 19, 2019

I agree it is not necessary. It may be that those who have stalling issues are a result of more radical engines. Possibly more of a tuning issue than the vss signal.
My engine is still the oem configuration and having the vss may be doing very little for me. I should unplug it and see what the results are one day.

The Luke · Feb 19, 2019

Just called up Brendan with Lt1swap.com. He said since it is a dbc setup the vss isn't needed. I'm going to have this harness down to a dozen wires in no time. Lol

I appreciate the help guys

Sawzall · Feb 19, 2019

Just have the ECM tuner turn off the VSS sensor so a code won't be set.

The Luke · Feb 19, 2019

That's exactly why I called him. He's flashing the computer next week.

87_bigbadzuk · Feb 20, 2019

I had Brendan do my 04 5.3 computer which is dbw. Also just had him do afm delete on my 07 burb. Used his free info to do my harness and everything works perfectly and was cheap. Def the guy to go to.

30th6 · Feb 20, 2019

I have a 08 5.3 in mine and I cut down the harness. It would hang throttle about 2500 rpm before I got it retuned. The computer always sees like 197 mph or something crazy but never had a issue after the retune. I have a th350/205

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ssidener · Mar 13, 2024

The Luke said:
Just called up Brendan with Lt1swap.com. He said since it is a dbc setup the vss isn't needed. I'm going to have this harness down to a dozen wires in no time. Lol

I appreciate the help guys

ssidener · Mar 13, 2024

Hi guys, i just did a DBC 5.3 swap with a SM420 tranny. I also came across the speed sensor issue. From the sound of the previous posts above, all I need to do is have the Tuner delete it out of the system. Any other recommendations while he's in there?
Thanks, in advance.