$EE VSS out voltage

[n8sh4de]

Hi guys,
I'm still having my cruise controll problem at my 95 vette.
I've checked all signals from the PCM now and got just 4,8V at the B8 pin (vss out), which goes to the CCM and cruise control. The manual says 6,5V with ignition on and 7,5V with engine running.

The voltage from the VSS sensor itself is a sine wave that varies from 0V when I'm standing and goes up to about 10V when driving 60 mph, which should be correct I think...
...just for info, I get the error code 24..

Any ideas? Do I have a faulty PCM?

Max

[lionelhutz]

I'd have to check my car to know. I'll see what I can do maybe tomorrow. I had believed that output was an open collector that basically grounds each time the PCM creates an output pulse to the speedometer and cruise circuits.

[n8sh4de]

I'd have to check my car to know. I'll see what I can do maybe tomorrow. I had believed that output was an open collector that basically grounds each time the PCM creates an output pulse to the speedometer and cruise circuits.

Yes, it should be 7,5V which are getting grounded, depending on vehicle speed.
The service manual has just solutions for a 14V signal and a 0V signal. For 4,8V there is no description.

The PCM groundings are all ok...