: 98+ STS brake upgrade?

11-07-09, 10:54 PM
I get a bit sick of seeing the message "traction suspended" on my STS. I researched the reason behind this: overheated brakes?

Does anyone make a brake upgrade kit for the newer FWD STS platform? If not I think I'll be able to figure something out. That 04 Pontiac GXP I just bought has massive front brakes, and I believe 2 piston calipers. Correct me if I'm wrong, but wouldn't the brake setup from the GXP bolt right on to an STS? They share the same chassis....

11-08-09, 01:29 AM
Seeing as you have both vehicles, I know one easy way to find out..........

11-08-09, 12:15 PM
Yeah I just thought someone here might already know....

11-08-09, 02:53 PM
I believe this all belongs down in Suspension, Brakes.......but STS2003 and others have had some success with the same years of Buick Lucerne brake swaps. Huge brakes.

11-08-09, 04:18 PM
I don't mind the brakes so much as the overall mushiness of the pedal. The new DTS's and STS's don't have this problem.

11-09-09, 03:46 PM
Jake, while the bigger rotors may keep the brakes from actually overheating, I dont think the car monitors the actual brake temp. I remember someone explaining that it is actually calculating/approximating the brake temp according to how you've been driving. Swapping out hardware may not solve the problem (if this is actually your problem)

Do you get a "brakes overheating" message? I'd have to check my FSM, but I think it will come up and tell you if this is what is actually happening, though if it's due to burnouts/TC, I dont know if it will come up.

11-09-09, 03:50 PM
I don't mind the brakes so much as the overall mushiness of the pedal. The new DTS's and STS's don't have this problem.

Have you flushed your fluid lately? If not, I bet it would make a HUGE difference.

11-09-09, 03:57 PM
The last time the fluid was done was sometime in late '06 when the original owners had the car. I should probably get that (along with transmission) done at my next service.

11-09-09, 04:06 PM
ryannel, Your car should have a progressively firm brake pedal. Travel a third to halfway to the floor, no more unless it's the ultimate panic stop.

FWIW, take it to a dealer and have them do a machine brake fluid change. You'll never see much in print, but techs and shops as well as brake fluid manufacturers recommend a complete brake fluid change every 2-3 years as standard maintenance.

11-11-09, 01:19 PM
Sorry Sub wrong category...

It was the "traction suspended" message which the manual says is due to brake temp, and does it really have a temp sensor? I doubt it. Bigger brakes are always a good thing anyways, even if the upgrade won't take care of that message. It only does that under hard driving conditions.

11-11-09, 01:56 PM
No brake rotor or pad temp sensors per se; the temperature warning is based on a computer algorithm which factors in speed, brake application, slowdown rate, total braking time and total non-braking rotor cooldown time based on OEM brake installation specifications.

Replace the calipers/rotors/pads with non-OEM units and all bets are off.

11-13-09, 08:12 PM
Yeah I explained in a tread all about this. The brake temperature is calculated not measured and assume the brakes are OEM. No matter how big are the brakes the computer has no way to know so this message can not be suppressed.
This reminds me some morning I was running late for work, then some 2-3 slow drivers with no habit of checking the mirrors or just no reason to be behind a steering wheel (not aware about traffic they keep behind and such). So I just trashed the car literally all the way to work. Several times I braked form over 120 MPH to almost stand still. At some point I had to stop at a traffic light and I noticed the smell of hot metal and I could see the air moving around the fenders (like the mirage in the desert). Those were definitely my front rotors overheated, I did not give the chance to the traction to engage (“burning rubber” is the worst you can do to a transmission).

11-14-09, 04:43 PM
Looks like we're back to square one with the PCM controls, taking over the car.

We need a highly skilled electronics expert and programmer to design a whole new PCM to control the car or to modify the stock one. What ever is legal and possible (even if it's for off road use :) ) Vasi........can we hire you to help?? :D

This is what we need to do. We need to find one of the original programmers who programmed the stock PCMs. Maybe they can do something, write us a new .bin file that will:

-keep 1st gear with T/C off
-eliminate torque management with T/C off
-eliminate the traction suspended message and 1st gear disable
-tune the stabilitrak for even better (firmer) handlng (not quite as necessary)
-change the timing curve


I know if the right person got paid enough, it would be possible. Man designed the PCM, man can modify it.

I know my shop will soon have some money to put toward further R&D. Maybe not enough for this but with a group effort we should be able to pull something off. I have John Zinser's direct line, maybe he'll tell me who was in charge of PCM programming and give me there contact info.

Sorry to say but almost every car can be electronically re-tuned. Why not a Caddy. I know the Cadillac brand is something GM doesn't want people messing with too much. The more Cadillac enthusiasts there are, the more new Caddys will sell. A good aftermarket and the ability to make changes will help sales. Not all owners will want to keep there Cadillacs bone stock. Yes they are amazing in stock form. But there are always things that can be improved upon.

And yes Vasi you are absolutely correct- burning rubber will kill transmissions quickly. Even worse is a sudden re-gain of traction.

There are certain PCM controls that can be defeated or the parameters modified by means of changing the inputs and outputs. I'm working on something for spark timing. I have some ideas but nothing too good so far. I had an LT1 that was modified to run on LP gas. they used a unit wired in line with the PCM to simulate signals to the PCM and change timing. That's what we need.

11-14-09, 06:51 PM
OBD1 computer controlled car?

I drive brake so hard and have never gotten that message!. strange

11-14-09, 09:16 PM
A while back I went on a double date with a chick from Germany. We went bowling and made a bet that if she won she could drive my STS. Big mistake. She won.

She was accustomed to driving BMWs on the autobahn. I was in the passenger seat and and I had never seen anyone drive like that. She thought she knew how to handle a car and wanted to impress me. Almost hit one car, and almost side swiped a steel post. I tolerated this as long as I could and finally reached over and turned the ignition off. I asked her to get out and take the passenger seat. I was a little ticked off, so I gave her a crash course on how to handle a car. I took a corner at a good speed and had all four tires sliding around the corner. I kept it in perfect control. But then I lost first and "traction suspended" came up again. All I heard from her after I gave her the ride of her life, was "lets do it again".....

Oh how I miss RWD. So much more you can do with RWD...

11-20-09, 09:25 AM
that reminds me of when i first got my car and was still learning it... a little mishap i had. This was before the engine swap. I was racing a GXP. I had no 1st gear and he kept pulling ahead on me till i hit mid range in 2nd. (actualy i had a 1st gear cheat. I could clear the code and it would get 1st but would shift at about 5k).

I had gotten pretty far ahead and realised the needle was buried. There was a T-bone intersection about 1.5-2km's ahead with a slight s-bend on the way, and i started to slow down. Im guessing here, but at about 900 meters i was still doing 160 or so and had the brakes to the floor, massive brake fade. I was turning from a 4 lane to a 2 lane, and just decided if i didnt give it a shot i was gona end up in the field. Kinda mumbled something like "so much for this car". I rode the right lane as far as i could and just eased the wheel; smooth but hard left. It screamed VERY loud, all 4 tires, and the car just planted itself into the right lane after a complete 90 degree turn. I figure i had found the cars limits that night.

**(all speeds in km/h)