"Service Brakes Soon"

[Doubeleive]

I was surprised too and I do not know how they tested the booster to arrive at that issue resolution. Since it only came on (briefly but a couple of times and whenever I trailer) I suspect that the extra weight of the RV on the booster (if it was having issues) would be when the light would come on. However, it seemed to break fine every time.

I have just never heard of the brake booster causing a "service brakes" warning before, nore from a trailer being connected. I suppose it's not impossible but I had the problem in the past and I dug into it extensively and no where did I find anything pointing to the brake booster. It boiled down to the fluid sensor or stuck prop valve (without a abs light on).
the brake system has a way of detecting the impedance and knowing if there a issue electrically, like a burnt out bulb or bad ground, bad brake switch, etc but that just results in cruise control not working

 

[Doubeleive]

right but if your yukon has a integrated trailer brake control then there is a trailer brake module, which if it has or detects a problem it will show "service trailer brake system" on the dic, that system is different.

 

[donjetman]

What RPO code for trailer brake controller?

 

[Foggy]

right but if your yukon has a integrated trailer brake control then there is a trailer brake module, which if it has or detects a problem it will show "service trailer brake system" on the dic, that system is different.

That's what I encountered ... Service trailer brake... When I was hooked up to my camper

 

[Foggy]

What RPO code for trailer brake controller?

I think it's the JL1 or JL4.. But not 100% confident.. I looked at my RPO .
When I bought mine, one of the criteria was the Integrated Trailer Brake Controller option...
I just swiped left on ones that didn't have it

 

[Doubeleive]

What RPO code for trailer brake controller?

pretty sure it is jl4, the tech2 always ask's

 

[donjetman]

pretty sure it is jl4, the tech2 always ask's

JL4 is for Stabilitrac or active brake control, not trailer brakes.
JL1 is integrated brake controller.

 

[Doubeleive]

JL4 is for Stabilitrac or active brake control, not trailer brakes.
JL1 is integrated brake controller.

 

[Johnms]

Just picked up the vehicle. They said it also needed the Master Cylinder. That makes more sense than the brake booster. Brake Booster $250, Brake Pressure Switch $150, Master Cylinder $175, Labor $460 plus tax. Grand total $1147.

 

[Doubeleive]

Just picked up the vehicle. They said it also needed the Master Cylinder. That makes more sense than the brake booster. Brake Booster $250, Brake Pressure Switch $150, Master Cylinder $175, Labor $460 plus tax. Grand total $1147.

smells fishy to me, but I guess if it solves the problem, good luck
I have put hundreds of thousands of miles on gm vehicles and never once had to replace any of that, leaking/stuck calipers is about it.
on some much older vehicles yes, maybe I have just been lucky
and I drive these things like race cars, my mpg is less than 10