What year trucks use a PSOM?

[cpdenton]

I am converting my vacuum operated cruise system to the newer solid state electronic unit. I want to write a tech article about the process involved here as well.

The electronic cruise revolves around an input from the PSOM(programmable speedometer odometer module).

It takes the speed signal and converts it to 8000 pulses per mile. I know all OBS trucks used a PSOM, what about any other years?

I want to give a proper tech article here! Thanks in advance.

 

[jay22day]

Good luck and im looking forward to reading the tech article this is pure speculation but maybe they didnt start using that until, as you said, the PSD

 

[cpdenton]

What I have found so far.

92 model trucks used a vacuum module with a speed control computer basically. PSOM in the gauge cluster to signal the speed control computer.


93 and 94 model IDI trucks use an electronic cruise module with the computer built in to it. PSOM controls it. No computer under the dash to control it.

pSD trucks do not have a cruise module as they do not have a throttle cable. It's all built in to the pcm.

I was really curious if brick nose trucks use a PSOM. I think no, but want to be sure.

 

[The Warden]

The electronic cruise revolves around an input from the PSOM(programmable speedometer odometer module).

It takes the speed signal and converts it to 8000 pulses per mile. I know all OBS trucks used a PSOM, what about any other years?

I was really curious if brick nose trucks use a PSOM. I think no, but want to be sure.

Brick-nose and slant-nose trucks have mechanical speedometers and odometers; the electronic speedo (and the PSOM) started in 1992 with the OBS trucks. IIRC on '80-'91 trucks the speedo cable connects to a unit that gives a signal to the cruise control brain-box (with another cable connecting that to the speedo head)...I don't know if that sensor gives the same 8000 pulse-per-mile output for the brain-box that the PSOM does. If it doesn't, this might mean that the electronic cruise control conversion won't work on pre'-92 trucks.

I have a cruise brain-box that I pulled out of a brick-nose truck laying around somewhere...if you want, I can try to find it in the next couple of days and post a part number, to see if it's different from the later brain-box?

 

[cpdenton]

We will get this figured out!

Someone probably has already, but I can't find it!

Even if it weren't exactly 8000 pulses, if it were close, it might still work.

 

[FORDF250HDXLT]

my '93's have the electric servo's.ford used the same little boxes in all kinds of their cars and trucks.my last car (mazda 626) has the same ford servo.reminds me,i should pluck that off before taking it in for scrap.......but i never use cruise anyway lol.

 

[cpdenton]

The electronic servos are really simple too. Power in and ground. Signal from PSOM. Wires to the switches. Brake light switch and then that brake pressure switch that goes in the master cylinder. That's it.