Factory integrated brake controller not recognizing trailer.

[swathdiver]

Not sure if this is correct, but in this pic, between ground (pin B), and Pin C, I have .9 ohms.

View attachment 377064


Also, is this a relay for the brake controller?

View attachment 377065

Number 1 and 2 refer to the controller on the dash and this is the connector:



I don't know what that relay is for; it is not the SSR.

 

[dkad260]

Thanks for all the help....but do you have the pinout for the brake controller?

Which is ground?

Sorry, I don't have the diagram for the brake controller.

I went ahead and verified I had continuity between the 7 pin blue and the blue terminal at the TBCM, also ground was good and I have good ground at the trailer.

 

[dkad260]

Going back to an earlier post, I did not see a SSR near the ABS pump.

Here's the pump..




And another module behind it, didn't see any relays.

 

[dkad260]

Are you referring to this, that's above what I believe is the fuel pump controller. Mine is mounted above the spare tire along the cross members.

 

[dkad260]

Well, I figured worst case I would have some spare parts. I went and installed a new module and new gain switch....still no change. I have 12V at the module, and the blue wire is good from the module to the 7-pin connector.

At a loss for the moment...

If anyone want's to PM me and set up a phone call feel free...

 

[swathdiver]

Updated earlier post with pinout, sorry, forgot about that.

Ok, if the module is bad, you just cannot plug in a new one and carry on, it has to be programmed through ACDelco's TDS system. If you don't have a laptop and subscription to TDS and the interface and all that, it may be less expensive and time consuming to have a local GM dealer do it for you.

There are some photos of where the SSR is in this old thread:

Where Is My Solid State Relay (SSR)???

I showed the 2 places it will be in my jul14 post with photos, the 2nd photo shows it is on the top (fig. 16), that is directly from the gm service manual.

www.tahoeyukonforum.com

Was looking for weeks until someone found it for me! LOL

 

[dkad260]

Mine wasn't along the frame rail, but above the spare tire between the cargo floor and the crossmember....this is what I replaced..

 

[swathdiver]

Mine wasn't along the frame rail, but above the spare tire between the cargo floor and the crossmember....this is what I replaced..

I would love to learn their logic in placing those things in different places! LOL

Yours is right where the books say it's supposed to be! LOL

 

[dkad260]

The relay could have been EASILY placed near the receiver. GM really went out of their way to hide it. One bolt was in the open, the other is under the FPCM so you have to remove the FPCM to access the 2nd bolt.

The bolts to remove the FPCM are a T30 and are ABOVE the mounting plate.

It gets better....if you don't have a slim 1/4 bit ratchet, you have to remove the mounting plate that holds the FPCM and trailer relay, in which those bolts are ABOVE the cross members....threaded down into the crossmember.

Complete insanity.

 

[swathdiver]

The relay could have been EASILY placed near the receiver. GM really went out of their way to hide it. One bolt was in the open, the other is under the FPCM so you have to remove the FPCM to access the 2nd bolt.

The bolts to remove the FPCM are a T30 and are ABOVE the mounting plate.

It gets better....if you don't have a slim 1/4 bit ratchet, you have to remove the mounting plate that holds the FPCM and trailer relay, in which those bolts are ABOVE the cross members....threaded down into the crossmember.

Complete insanity.

How is it working out today?