VELOCITY SPEED SENSOR INPUT in a impala E38 pcm LZ4

[Paoloz]

hello I need to find where to connect a VSS in a E38 pcm for a LZ4 impala engine

The engine is swapped and no VSS is connected (by the way which is the voltage it can accept +12/0 volts is ok?)

thanks for your help

[blindsquirrel]

If the V6 E38 is anything like the V8 E38, an auto trans operating system will never, ever be able to read a direct-wired VSS. The auto trans OS will only look for a vehicle speed signal that comes in on the CANbus, from an auto trans TCM, which you no longer have if you've done a manual conversion. This is a problem if you pick a donor for a swap that was never built at the factory with a manual trans option.

[Paoloz]

If the V6 E38 is anything like the V8 E38, an auto trans operating system will never, ever be able to read a direct-wired VSS. The auto trans OS will only look for a vehicle speed signal that comes in on the CANbus, from an auto trans TCM, which you no longer have if you've done a manual conversion. This is a problem if you pick a donor for a swap that was never built at the factory with a manual trans option.

I have the TCM also togheter with the ECU installed at this point the question is where to connect the speed sensor to the TCM

[blindsquirrel]

Pins 16 & 41 at the TCM, I guess?

You really have to post the tune file and give a better description of what parts you are using and what has been changed from stock when you make a thread like this, no one knows these things if you don't tell them.

For instance when I open GM eSI to look up diagrams for you, the very first selection I have to make is 'Year:' and I don't even know that much. I'm stopped dead in my tracks right at Step 1.

[Paoloz]

sorry engine LZ4 from impala 2009 with TCM,

Engine is installed with a manual gearbox,

attached the htp file of the ECU

I found a TCM pin out that tells pin 3 and 26 but for ISS but I'm not sure it is right and that this should be the input

[blindsquirrel]

ISS is Input Shaft Sensor. The part you no longer have when it's no longer got an automatic transmission.

VSS is Vehicle Speed Sensor. This is on the output shaft of the trans.

If you have a 2009 why are you posting a 2008 pinout chart?

This is 2009 Impala 3.5L 4T65E:

screenshot.31-10-2023 11.48.44.png

[Paoloz]

Just because i found this and didn't know it was 2008 instead of 2009.
So input is 16&41 can I use a 12v active sensor or I m obliged to use std variable reluctance magnetic passive sensor?
thanks for your help

[blindsquirrel]

Try it and see - I don't think it will work with a plain square wave but I also don't know anyone who has tested it with all the different sensor types.

You aren't going to find a step-by-step instruction manual for this one-off custom thing you're building unless you put on your lab coat, grab an oscilloscope, and write the instruction manual yourself.

[Paoloz]

Thanks I’ll do!

[Paoloz]

ISS is Input Shaft Sensor. The part you no longer have when it's no longer got an automatic transmission.

VSS is Vehicle Speed Sensor. This is on the output shaft of the trans.

If you have a 2009 why are you posting a 2008 pinout chart?

This is 2009 Impala 3.5L 4T65E:

screenshot.31-10-2023 11.48.44.png

in the 2009 diagram I dowloaded there is VSS only for LS4....
connettore AT.JPG

[gtstorey]

So what is pin 41 labeled as? That is what pin should be the VSS signal based upon what BlindSquirrel posted.

If there is conflicting information, I would probably trust the wiring diagram more than the connection pin out.

[Paoloz]

I had the same doubt the pin41 is labeled as Signal High maybe they refer to speed sensor but they do not write VSS.........


pin41.JPG

[gtstorey]

I would go with saying the description just isn’t very clear since the circuit number 400 and the wire color matches.

[gtstorey]

And the low side of the circuit also matches for pin#, circuit #, and color.

[Paoloz]

Yes I did noticed , so probably it is the right input