What IC in VSS buffer circuit GM.

[Dennis Bell]

I believe the IC is a Delco only part. Haven't found a generic match to it. Functionally it is a buffer between the optical switch in the speedo head and the ecu and cruise control. I've traced out the schematic of the buffer from an 89 Caprice and have it in Orcad format. I don't have access to a scanner to provide it in a common file format.
Basically the chip is powered from 5 volts on pin 2, pin 1 is ground. Pin 4 is the input from the optical switch. Pins 7 and 8 are open collector outputs of the signal on pin 4. Pin 7 goes to the ecu and 8 goes to the cruise control.
The output pulse rate from the speedo is usually 2 pulses per revolution yeilding 2002 pulses per mile.

hth

Dennis


Goran Carlsson wrote:

> I have a GM G20 VAN 1989 5,7 l. Between the VSS sensor (located at the rear of speedo) and the ECM there is a VSS buffer circuit. The box contain a small circuit board with one IC and a few resistors and capacitors. The IC is labeled 6962H (8 pin). Í guess it is a GM type since I have not been able to find it in any Data-books. Question: Do you know what type of IC this is??
>
> Please help
>
> Goran