Gen IV E38 with VVT and a manual will it work?
Teching In
Joined: Jul 2018
Posts: 6
Likes: 0
Updated:
I got the VVT deleted and the BTR stage 2 cam in. I also edited some fields in the Torque Management section (12836 specifically) that was in the Default torque limit area. All of the values for >3500 rpm were set to negative numbers. I replaced those with 500. Reloaded the tune and the 4000 rpm rev limiter is gone for good.
It also makes sense in this situation where there is no TCM (manual transmission in my swap). Thus it defaults to these limits as it states in the small text at the bottom.
It may also explain why I have somewhat less than ideal power delivery prior to 4000 rpm currently, but once it hits that it pulls super strong. I'm going to go back and set the sub 4000rpm limits to higher and see if that makes a difference.
Last edited by LY6CJ7; Mar 15, 2019 at 12:57 PM. Reason: clarification
On The Tree
Joined: Jan 2019
Posts: 103
Likes: 3
From: north-central Virginia
I'm also installing a Gen IV e38 engine into a manual vehicle. This one actually came out of a 4x4 tahoe, and it used pins 71 and 72. So apparently, there was a VSS in the transfer case on the tahoe, to correctly read speed in low or high range. I'm guessing that I can run a SEN-01-128 directly into pins 71 & 72, and it will work perfectly. IF it works for me, I would be suspecting the reason some folks have no luck getting a VSS signal to the ECM, and others don't have a problem, is the difference between a 2wd and a hi/lo 4wd computer tune.
When I get it rolling, I'll try to update this thread with my results.
When I get it rolling, I'll try to update this thread with my results.
I'm also installing a Gen IV e38 engine into a manual vehicle. This one actually came out of a 4x4 tahoe, and it used pins 71 and 72. So apparently, there was a VSS in the transfer case on the tahoe, to correctly read speed in low or high range. I'm guessing that I can run a SEN-01-128 directly into pins 71 & 72, and it will work perfectly. IF it works for me, I would be suspecting the reason some folks have no luck getting a VSS signal to the ECM, and others don't have a problem, is the difference between a 2wd and a hi/lo 4wd computer tune.
When I get it rolling, I'll try to update this thread with my results.
When I get it rolling, I'll try to update this thread with my results.
On The Tree
Joined: Jan 2019
Posts: 103
Likes: 3
From: north-central Virginia
I don't have it running yet. I have learned a couple things, though. The Sen-01-128 is a three-wire Hall Effect sensor, and likely will not work with the e38 ecm. The GM ecm's want to see a two-wire Variable Reluctance sensor instead. Sen-01-4160 is an example of one.
Also, for some unknown reason, I probably can't simply pin VSS into an auto-trans 4x4 e38 ecm and have everything work out okay. Folks who have tried it says the ecm sees a continuous 158 mph speed, and the only thing that fixes it is to wire in a t42 trans controller. I'm shifting direction a little, and will be flashing my ecm to a Corvette operating system. This should give me perfect manual transmission control and give me a working VSS. The question is whether I can get my VVT working on that manual trans tune or not.
Also, for some unknown reason, I probably can't simply pin VSS into an auto-trans 4x4 e38 ecm and have everything work out okay. Folks who have tried it says the ecm sees a continuous 158 mph speed, and the only thing that fixes it is to wire in a t42 trans controller. I'm shifting direction a little, and will be flashing my ecm to a Corvette operating system. This should give me perfect manual transmission control and give me a working VSS. The question is whether I can get my VVT working on that manual trans tune or not.
I can confirm the 158mph issue, but weirdly, the ECM does provide a functional speedometer output. I still haven’t got my tach output working, however, and I can’t make the reverse lockout work.
I’ve had a hard time finding a compatible OS from a manual car. I’m told the L99 Camaro with VVT and manual might work. If you find an OS from a manual car that you can write to the truck ECM, please let us know the details.
I’ve had a hard time finding a compatible OS from a manual car. I’m told the L99 Camaro with VVT and manual might work. If you find an OS from a manual car that you can write to the truck ECM, please let us know the details.
On The Tree
Joined: Jan 2019
Posts: 103
Likes: 3
From: north-central Virginia
In a manual car, when the speed is around 3mph or less, the ECM energizes a solenoid on the side of the transmission that allows the shifter to easily slide all the way over to the reverse gate. If the solenoid does not energize and withdraw the blocking pin, you have to apply a lot of force to the shifter to get onto reverse. It happens to be the same ECM pin that controls one of the AFM solenoids on the automatic cars with Active Fuel Management…showing that GM never intended to have the E38 work with AFM on a manual. I still haven’t found a workaround.
