LSx Vehicle Speed Sensor feed to PCM to Ultima speedometer

[2001ultima]

Has anyone run a VSS signal to the PCM and then run from the PCM VSS out to an Ultima Speedometer?

[2001ultima]

ultimichael said:

If PCM means ECU I have done it this way but using a VDO speedometer.
Why do you ask?

Michael

Well right now I don't have a VSS for the ECU. The current hall sensor drives the Ultima Speedometer. So it would be nice if I could replace the existing hall sensor and then switch over to the ECU wires and have the ECU VSS out send the signal to the Ultima speedometer.

[2001ultima]

Steve_D said:

Many just use speed to detect you are still moving but with no throttle such as running down to a junction or traffic lights. In this case it will hold the idle up at say 1100 or 1200 rpm for a few moments after you stop the idea being that it prevents a stall or stumble. When it knows you are stopped it will drop the idle to approx 900.

Steve

Regarding the advantages for a VSS feed to the ECU
1. Same understanding as Steve regarding raising the RPMs when slowing to a stop/junction.
2. When cruising on the highway the engine can adjust to run more efficient.
3. LS Tuners that provide a street tune, capture ECU stats as the car is driven. If the tuner has the speed recorded as well there is more information for the tune.

If the VSS is calibrated with the ECU the exact speed of the car can be read from the ODB port as you drive.