Vehicle speed input into e67 pcm, which pin(s) ??

[Bullwinkel]

This is my first post.

My hot rod has a 2008 Cadillac LC3 engine with a Northstar 4t80e trans/transaxle. The engine uses the OEM E67 PCM and I have an aftermarket TCM to control the trans.

The torque converter has a 4000 rpm stall and the engine sometimes stalls when I let off the throttle and coast. The high stall of the converter does not let the momentum of the vehicle
do any engine braking to help maintain the rpm above a normal idle. I would like to use the feature of HP Tuners to increase the idle speed when the vehicle is moving. But, the E67 PCM does
not know the vehicle speed. The electronics of a 4t80e and 4l80e are very similar. I was able to use the VSS signal from the 4t80e to supply input to my aftermarket TCM (Powertrain Control Solutions)
and speedometer (Racepak) but can't figure out how to send this information to my PCM. I have programed the idle at 1100 rpm to prevent stalling but it would be nice if it would go down to
a lower value when at a stop light.

Does anyone know which pin(s) can be used on an E67 PCM to input this data? I have surfed the internet for hours with no success. Maybe I am using the wrong search criteria or ??

My documents show that pin 39 of the C1 connector supplies a VSS output but can't find pin(s) for the input. (The VSS currently goes directly to from trans to TCM and Spedometer.)

Thanks

[Bullwinkel]

I think I found the answer. VSS HIGH IS PIN C3-66 AND VSS LOW IS C3-67
You may want to look at https://www.hptuners.com/forum/showt...Auto-to-Manual.