Vehicle Speed Sensor (Page 1/1)
Chief08 AUG 25, 01:35 PM
I'm going to be adding some custom gauges and electronic cruise control soon, in addition to a LS4/F40 swap. Is the VSS in the Fiero different than the one in the F40?

Thanks,
Chief
theogre AUG 25, 02:07 PM
Fiero VSS is a Generator type puts out 4000 pulse per mile. Is why can test VSS w/ AC Volt meter when you think they are bad.
Converting to Aftermarket Speedo... Problem is Fiero Speedo has Buffer/Divider circuit build into it to output 2000 ppm for ECM and Cruise.

IOW Not like many other GM vehicles w/ standalone Buffer/Divider units that don't care about what Speedo is used.

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(Jurassic Park)

The Ogre's Fiero Cave

Chief08 AUG 25, 02:48 PM
Thanks Ogre. For the electronic cruise, I have to specify the VSS output, which is why I was wondering if the Betray and the F40 have the same VSS output.

[sup][/sup]
quote
Originally posted by theogre:

Fiero VSS is a Generator type puts out 4000 pulse per mile. Is why can test VSS w/ AC Volt meter when you think they are bad.
Converting to Aftermarket Speedo... Problem is Fiero Speedo has Buffer/Divider circuit build into it to output 2000 ppm for ECM and Cruise.

IOW Not like many other GM vehicles w/ standalone Buffer/Divider units that don't care about what Speedo is used.
fieroguru AUG 25, 05:10 PM
If you keep the 88 Fiero cluster, it has 4000 ppm output... I forget the pin, but it was going to be used for power steering.
The Fiero Getrag VSS also has a 4000 ppm output that you can tie into directly.
The F40 uses a magnetic VSS and generates a signal about 60000+ PPM. It normally is wired directly to the TCM/ECM and then the ECM provides (with the help of a signal converter circuit) a 4000ppm signal for the speedo, cruise or whatever.

If you are installing this electronic cruise module before installing the LS4, then it likely is cable operated. The LS4 is DBW, so to use that cruise module you either need to swap ecms and convert to a cable throttle body, or fab up a bracket to pull the LS4 DBW pedal.

If you are using a 05/06 LS4, then you can keep the factory DBW crusie feature and avoid the aftermarket module all together. The cruise response with this method will be just like any new car (1 touch, speed is locked in, zero lag) . With the older modules there is a lag and fine tuning the cruise. Press Set to engage cruise, press the accel button to pull the slack from the cable, release the accel button, see how close you are to the target speed and make the final adjustments.
Chief08 AUG 25, 05:35 PM
I'm having the gauges custom made by Dakota Digital, and just about everything will be integrated into them, turn signals, high beam indicator, door ajar, cruise on, etc. I'm guessing there won't be much of the original cluster guts left. If I can use the DBW cruise from the LS4, that would be the best option. In that case, is it controlled via the Fiero's stalk mounted controls?


quote
Originally posted by fieroguru:

If you keep the 88 Fiero cluster, it has 4000 ppm output... I forget the pin, but it was going to be used for power steering.
The Fiero Getrag VSS also has a 4000 ppm output that you can tie into directly.
The F40 uses a magnetic VSS and generates a signal about 60000+ PPM. It normally is wired directly to the TCM/ECM and then the ECM provides (with the help of a signal converter circuit) a 4000ppm signal for the speedo, cruise or whatever.

If you are installing this electronic cruise module before installing the LS4, then it likely is cable operated. The LS4 is DBW, so to use that cruise module you either need to swap ecms and convert to a cable throttle body, or fab up a bracket to pull the LS4 DBW pedal.

If you are using a 05/06 LS4, then you can keep the factory DBW crusie feature and avoid the aftermarket module all together. The cruise response with this method will be just like any new car (1 touch, speed is locked in, zero lag) . With the older modules there is a lag and fine tuning the cruise. Press Set to engage cruise, press the accel button to pull the slack from the cable, release the accel button, see how close you are to the target speed and make the final adjustments.