Disabling traction control in '95 Fleetwood LT1

[Byron]

Find someone with a Tech II
Very simple to do

[steveo]

On my '95 Fleetwood, using TunerPro, I have unchecked the "set" box in the traction control flag, and also set the traction control spark retard to zero for all rpms, and yet the traction control still kicks in.

all the ECM does is receive a traction control request and retard timing per RPM range.

you've probably disabled that part. perhaps there's a brake actuation or throttle angle control subsystem that exists outside of the ECM. kinda like the ASR system on f-bodies.

[lionelhutz]

Like Steve posted, the traction control is done outside the PCM, likely in the ABS braking systems. So you need to disable that system to disable TC. All the PCM does is respond to the ABS module requesting a timing cut to reduce engine power.

On a similar note to your question, my GM truck has a TC disable button and when I press it it says the TC is disabled in the display. But, only the timing cut in the PCM is disabled. The rear brakes will still apply which means the traction control in the EBTC module is still fully functioning despite me being able to apply full power with the wheels spinning.

[FUN-9C1]

Thanks for the replies, that makes sense. Glad to understand how that works.

[schlicky13]

Quick question, slightly off topic: on your Fleetwood were you able to simply plug in and start messing around with tunerpro, or did you have any difficulties to sort out? I've been trying to datalog and tune my own '94 Fleetwood and have been banging my head against the wall for about a month now. Either there's something weird with these cars, something's wrong with my setup (choice of adapter, definition files, etc.) or something's physically/electrically wrong with my car that I can't isolate and also doesn't have any impact on driveability, (considering it's my daily driver and it runs perfectly). Didn't mean to thread jack, but as soon as I saw you were messing with a Fleetwood I got curious.

[steveo]

with the caddies, some guys have found you need to start yanking fuses until they get good communications. the hvac, body control module, abs, sir... there are so many body modules trying to use the ALDL bus it's hard to get good communications going.

[schlicky13]

Pulling fuses, that is the first I've heard mention of that and naturally it's so incredibly simple I never even thought of it. Per the norm, it's usually the simple stuff that trips me up. Although I had been contemplating unplugging the CCM from inside the trunk, just didn't know yet whether the car would still drive without it so that I could datalog. I was starting to suspect interference from the CCM since I found an old thread somewhere else where Corvette guys were having issues with the CCM's in their cars when trying to tune, but so far I had not found any info anywhere on the web yet about people having the same problem in the Fleetwoods. And obviously Impala/Caprice, Roadmaster and Camaro/Firebird guys don't ever run into it since those cars don't use a CCM. The Corvette crowd was able to work around it through very careful manipulation of the timing settings and repeatedly sending a command to the CCM signaling it to stop transmitting (basically telling it to shut the hell up).

There's also a small chance I do have something weird electrically going on, since I know I have a small handful of DTC's sitting in the history that I periodically clear, but eventually they come back. I had actually just come back inside from double checking them and most of the ones I haven't been able to track down and repair (there's only a few stubborn ones left) are either shorts or serial data communication errors. I need to pull my FSM and sit down with those and see what I can figure out. I may simply have a wiring issue somewhere since it is popping similar errors across multiple modules. I may also put a post on the Impala SS forum since it seems I read somewhere once the B/D cars have a couple known weak points in the wiring as they age. It's just frustrating since besides these issues, the car truly runs and drives perfectly. No idiot lights ever come on, it fires instantly when you hit the key, it idles smoothly, pulls like a freight train til you bang the speed limiter (I mean reach the legally posted speed limit ) and other than a few small drips I'm still trying to find the source of, the car is completely problem free. I just can't tune it and it keeps spitting out these few weird short/ground and communication error codes.

Anyways I'm clearly rambling on, but I appreciate your quick response and I hope the fuse trick helps. If it solves my issues and gets me on my way with tuning I'll let you know, but if I continue to have problems I'll probably just go sulk in a corner with a stiff drink while I ponder it some more. I'm definitely starting to wonder just how hard an LSx PCM swap would be.