Originally Posted by Phil Manwarren

the tccm

Originally Posted by christine_208

Hi all,

I thought I'd make a contribution to the knowledge base regarding how to get at the Body Relay Block (BRB).
This knowledge came about from a wild goose chase I was in an attempt o deal with a driver side door lock that was not working. The problem turned out to be due to one broken wire. https://blazerforum.com/forum/lighti...89/#post735615 The silver lining is that the forum is the beneficiary of what I learned while tyring to remove the BRB. LOL

First off here are a couple links that I used that were super helpful:
https://blazerforum.com/forum/lighti...hematic-81664/
S10 LS3 Project Blog: Power Seats - Part 1 (Dash Wiring)

I'll be using some of the pictures from the links above in my description below:

First the location:
The BRB is located up behind a frame on the driver side of the steering column. The first picture shows the clips where it attaches to the forward side of the frame at four points. Here the whole dash has been removed.

The attachment points for the BRB are circled. the upper ones in red and the lower ones in green. Below the green circles can be seen the wires that go into the BRB from below. The park brake pedal and regular brake pedal are in the bottom of the picture.

This is what the BRB and its mounting bracket look like when they are removed as a unit.

The left side of the BRB. The mounting bracket is on the left with the two of the clips that engage the metal frame on the right.


The right side and backside of the the BRB with the mounting points identified.


Top view of BRB with cap on.


Top view of BRB with cap removed.


But the BRB does NOT have to be removed with the bracket attached. There is a "quick release" tab as can be seen in these pictures.

The location of the quick release tab.

The BRB can be released from the bracket by inserting a screw-driver to lift a tab on the bracket from over a tooth on the BRB:

Where the screwdriver would be inserted to lift the tab off of the engagement tooth. The tab that is part of the bracket is highlighted in purple.


The bracket in place and the tab on it highlighted in purple. The slot for the engagement tooth is in the middle of the highlighted area. This view is from below and looking towards the back. This view is only possible using a mirror.



Where the tab on the bracket inserts (from the top of the BRB) highlighted in orange. The engagement tooth is unhighlighted in the middle of the highlighted area.


The view of the BRB bracket from below as would be the actual view from your eyes. The parking brake release cable is on the left of the picture.

To get the BRB out using this method that leaves the mounting bracket in place is a pain but still easier than removing the dash panels and removing the BRB with its bracket. I found that loosening the cap that covers the relays helped as it is all pretty tight in there.

Reinstalling the BRB is almost literally a snap once you get it aligned. I think again I left the cap a bit loose to help get it aligned.

I hope this helps and saves others a lot of hassle!

Originally Posted by Phil Manwarren

could this be why I can't connect to my diagnostic port ?