Just changed my TBI system to a SD TPI. Have most of the prom issues figured out, need help with the VSS issues. Since my tranny does not have the magnetic VSS, I am not sure what the down side to disabling the VSS code. I see that there are speed related fuel/idle constants in MPH. I am a rookie with the Tunercat software and I do not want to burn my new crate motor. Any help or advice will be greatly appreciated!
TGO Supporter
Do two things. 1) Wire your VSS to the 7730's ECM at pin BC6 (don't use the 4 wire method of wiring a 4,000 PPM VSS). 2) Set the "Mag Sensor Switch" off in the $8D eprom.
89 Iroc Z
Supreme Member
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Apr 17, 2026
You need version AB of the $8D definition file.
Here are the steps:
1) Load Tunercat
2) Select the right Definition file
3) Load the bin file
4) Click on tables and select ECM Switch Table
5) Take away the X by "Magnetic Speed Sensor Installed"
6) Save the bin
That’s all you have to do
Here are the steps:
1) Load Tunercat
2) Select the right Definition file
3) Load the bin file
4) Click on tables and select ECM Switch Table
5) Take away the X by "Magnetic Speed Sensor Installed"
6) Save the bin
That’s all you have to do
TGO Supporter
Quote:
Originally posted by 89 Iroc Z
You need version AB of the $8D definition file.
Here are the steps:
1) Load Tunercat
2) Select the right Definition file
3) Load the bin file
4) Click on tables and select ECM Switch Table
5) Take away the X by "Magnetic Speed Sensor Installed"
6) Save the bin
That’s all you have to do
You forgot "Turn on the computer".Originally posted by 89 Iroc Z
You need version AB of the $8D definition file.
Here are the steps:
1) Load Tunercat
2) Select the right Definition file
3) Load the bin file
4) Click on tables and select ECM Switch Table
5) Take away the X by "Magnetic Speed Sensor Installed"
6) Save the bin
That’s all you have to do
Okay I have the computer turned on, now what...
Have turned the "Magnetic Speed Sensor Installed" off in the ECM switch table. I have a question about Glenn91L98GTA's comment on wiring my VSS to the 7730's ECM at pin BC6. Are you referring to the optical VSS behind the gauges? Is the signal from this compatible w/ the 730 setup? Thanks for the pointers.
Have turned the "Magnetic Speed Sensor Installed" off in the ECM switch table. I have a question about Glenn91L98GTA's comment on wiring my VSS to the 7730's ECM at pin BC6. Are you referring to the optical VSS behind the gauges? Is the signal from this compatible w/ the 730 setup? Thanks for the pointers.
TGO Supporter
Just move pin "A10" (Brown 437) from the 165 connector to BC6 on the 7730 connection.
On a stock 7730, BC6 is not used - they use four different wires for the 4000 PPM VSS. By pinning A10 to BC6, this connects the older type VSS to the ECM.
On a stock 7730, BC6 is not used - they use four different wires for the 4000 PPM VSS. By pinning A10 to BC6, this connects the older type VSS to the ECM.
