Identification of part

[S.hafsmo]

Underneath the ECM there's a small device with an electrical connector, and what I can only assume is a vacuum hose connected to it. What is this device?
Mine has a slightly broken connector, which I would like to replace.

[WVZR-1]

Originally Posted by S.hafsmo

Underneath the ECM there's a small device with an electrical connector, and what I can only assume is a vacuum hose connected to it. What is this device?
Mine has a slightly broken connector, which I would like to replace.

I believe you mention your car being a '90 and that would be a MDP sensor (Manifold Differential Pressure). In your FSM check 8A-201-8

Here's an image from a GM SPO publication. Item#23 in image 16054920 for a part# I believe. There was I believe a replacing # that's also likely NLA but maybe Jerry can reference the original# for you. In your location if there was anyone that did ACD/GM these #'s would likely suffice in this order 16006834 (oldest and maybe NOT optimal), 16054920 (likely the OE in '90) and 16231141 (newest but maybe NOT the most desirable). Yours should likely have a 4 digit ID # on to use.

LT5 ECM.jpg

[S.hafsmo]

It is a '90, yes. Apologies for not including that in the initial post.

MDP makes sense. Much appreciated. I'll check the FSM as soon as I get back to Norway.

[WVZR-1]

Originally Posted by S.hafsmo

It is a '90, yes. Apologies for not including that in the initial post.

MDP makes sense. Much appreciated. I'll check the FSM as soon as I get back to Norway.

Are you here in the USA now?

here's the FSM image:

'90 8A-201-8.png

[S.hafsmo]

I'm currently in France (Rouen) - at work.

That looks just about right. The vacuum hose was disconnected when I got the car. Odd it didn't give any fault codes.

[Paul Workman]

Originally Posted by S.hafsmo

I'm currently in France (Rouen) - at work.

That looks just about right. The vacuum hose was disconnected when I got the car. Odd it didn't give any fault codes.

So, the question is: are your secondaries removed/tied open on your car? Chips that are programmed for secondary delete are calibrated to "see" atmospheric pressure as "normal". In those instances, the vacuum line IS disconnected from the MDP sensor.

[S.hafsmo]

I actually have no idea. Doubt it's disabled, but haven't been able to confirm. Will probably pull the plenum when I get home, then I'll know for sure.

[Z51JEFF]

Post a picture of the broken. Most likely I have an extra plug,getting it shipped is the only issue.

[WVZR-1]

OP - if you're needing the electrical connector there's a couple options. A correct connector I believe would be a GM# 12085507, ACD# PT128 OR a 3 terminal empty Delphi style Weather-Pack and you just transfer the terminal pinning. The indexing of the terminals are different I believe from a conventional MAP but I should be able to confirm. 'course there's also the possibility that if it's modified then you've no need.

This I believe should be the correct "indexing" for the connector. Maybe someone has a 16054920 on the shelf and can confirm.

LT5 - MDP indexing.jpg

[A26B]

This I believe should be the correct "indexing" for the connector. Maybe someone has a 16054920 on the shelf and can confirm.

I agree.