FAQ: Anti-Lock Brakes and/or Traction Control Light/Lamp On

I am having the same Traction Control Light coming on minutes after starting in all weather conditions. Also have the Anti-Lock Brake Light coming on intermittently. Took it to the dealer, where they replaced the EBCM with a used part.

When I took it in, they were getting the following codes:
C1215 Brake Control Relay Contact Circuit Active (now taken care of with the new used part)
C1274 RF TCS Prime Valve Malfunction (still getting this)

Service said that the EBCM is no longer available new. I've read through the 22 pages of threads and don't have a clear picture of the cure. The dealer did look for frayed wires to the unit; they look good. Does anyone know how to repair this problem?

What year is your car?

Abaddon wrote:

What year is your car?

1999

C1215 Suspect Valve Malfunction

C1274 BPMV Pressure Switch Circuit Malfunction

Don't know what "they" used to read the codes, but these are right out of GM's mouth.

It's possible you need a new BPMV (Brake Pressure Modulator Valve). Although, I would think you could trust the dealers' diagnosis. However, you still have a light and a code, so it isn't fixed. I'd be taking that thing right back to them. They can't charge you another diagnosis fee.

The only other things you could check for the C1274 is the HZRD/STOP fuse under the back seat, or the actual Stop Lamp Switch could be bad (no brake lights), as it's in that circuit. Other than that or a bad wire, that code generally points to the BPMV.

Abaddon wrote:

C1215 Suspect Valve Malfunction

C1274 BPMV Pressure Switch Circuit Malfunction

Don't know what "they" used to read the codes, but these are right out of GM's mouth.

It's possible you need a new BPMV (Brake Pressure Modulator Valve). Although, I would think you could trust the dealers' diagnosis. However, you still have a light and a code, so it isn't fixed. I'd be taking that thing right back to them. They can't charge you another diagnosis fee.  

The only other things you could check for the C1274 is the HZRD/STOP fuse under the back seat, or the actual Stop Lamp Switch could be bad (no brake lights), as it's in that circuit. Other than that or a bad wire, that code generally points to the BPMV.

Thanks for the quick feedback! I'll take it back to "them" and see what "they" say. (It's my local Buick dealer.)   

Well, my light has been on for a while. It went out for a bit after reconnecting the right front harness that had somehow come loose, and then went out again briefly after a re-flush of the system, but now it generally stays on solidly.... or only goes out for a little while.

So I took it to the dealer and the following codes were reported on my receipt:

0021 0021 Right front speed sensor and/or wire harness damaged
0045 0046 inlet and out valve is shorting


Their dealer cost parts recommendation:

ABS Module $1303
Wheel Hub $488
Wiring Harness $183

Heh   


So, it is true that the wiring harness from the firewall to the wheel hub took a beating when I lost a belt. There's a 95 at the wrecking yard, so I'll go get that wire for $5

Then we'll see if the light remains on/off first.

I wouldn't be surprised if the ABS valve body has an issue since the car had sat so long and I had the master cylinder go bad and leak. But I've seen NOS units online for $400-600.

.

Hey everyone! seem to be having an issue with my abs. went to leave the driveway yesterday as i was reversing onto the street just as the front wheels hit the lower curb i heard my abs groan. thought ah maybe just a random thing. went to drive away slowly and my abs kept going off ( no brakes being applied only very light throttle ) startled, i stopped put it in park then back to d. turned off the traction control and that seemed to work, then about 5 mins after my anti lock light came on for the rest of my trip. when returning home the anti lock light was off and hasn't come back on since but I have heard the groan twice after this, not nearly as bad as when it first happened. definitely seems like the drive wheels are the one causing the issue as it happens on rough pavement usually while reversing. I've just been turning off the traction control now out of habit to keep it from doing this.

any ideas ?? could it be from the cheap ass wheel hubs i bought to replace the front when i first got the car ?

also noticed my brake fluid was black as midnight and lowish, no leaks from any lines but i definitely need brakes all around, front pads probably have 1-2 months at best left.

JR3800 wrote:

any ideas ?? could it be from the cheap ass wheel hubs i bought to replace the front when i first got the car

Probably. You're hearing the ABS engage because one of the Wheel Speed Sensors is off by about 5mph. What's happening is that the EBCM is seeing "0" on one wheel when the others are reporting "5" (this is an estimate). Same goes for when you're going faster. If one wheel reads lower than the rest momentarily, the EBCM will engage the ABS on that circuit because it's sensing a "wheel slip or lockup" condition. The ABS light came on because it happened for more than a certain amount of time, reporting a fault.
This can also be caused by a corroding wire/terminal. It's unlikely on the Riv though. Our ABS wires hold up pretty damn well.

This is what happens before it goes buh bye completely....a quick code scan will tell you which wheel to go after.

Yeah, what Abaddon said - a bad wheel speed sensor. It's common on 'cheap' wheel bearings. It's also very possible that a wire from the hub up to the chassis has been damaged.

If you have someone with a code reader that does ABS codes (most typical code readers do NOT) you can find out which wheel you should be focusing on. Don't replace that bearing until you've determined that the wiring is sound.

UPDATE the traction control light goes off when i'm parked and turning the wheel left to right, this is weird.

also would my aeroforce pick up the code ? would the code make my check engine light come on ?

TCS and ABS are a separate system from the PCM. The aeroforce can only read from the PCM that I know of.

If it was me, I would inspect both wheel sensors and wiring. Then go from there.

yeah the aeroforce shows no codes guess its only engine trans stuff
my buddy has a fairly decent scanner il see if i can grab it off of him maybe that one will pick up the code.

Will inspect them hopefully tomorrow, if the shops slow. I'm hoping it is so I don't have to jack this thing up in the driveway, its so cold out. plus everything is covered in an inch of road salt / brine.

canada eh

Agree with checking sensor wiring and connectors.
The brake fluid condition is a clue, though. If it's very dark, it indicates some oxidation of internal components - possibly the ABS pump. I would change out (bleed) this fluid regardless of what you find. It won't fix the problem, but is a good idea so the braking system functions to potential.

You can have very good brakes without the ABS functioning, or you can have poor brakes with completely functional ABS. Brake fluid can make that difference.

Okay everyone,
got a chance to pull the wheels and give everything a good look. both abs sensors were plugged in the wires seem to be in good shape up to the terminals, pulled them apart and they were clean on the inside. I cleaned them with some abs sensor safe brake clean to be safe, doesn't look like there is any splits in the wiring that leads to car. However when i turn the wheel left and right the trac light goes off and on. so maybe one of the connections isn't great?

other than that i'm not quite sure the bearings seem fine no weird noises when i'm driving other than the noise from the winter tires.

the anti lock light hasn't lit up since it appeared the first time and then it was only on for the one 5 minute trip and haven't seen it since.

and yes AA, i plan on doing a complete overhaul on the brakes soon as the weather permits,
is there a specific brake fluid that you would recommend?

The lamp illuminating when turning the wheel, that really seems to point toward front wheel sensor wiring or connector.

I only use Ate Type 200, DOT 4. This is acknowledged in racing circles as a superior fluid, and I've put it to the test on many occasions. Available at Amazon in quarts for $20. Split the cost with a friend, or change fluid in multiple vehicles.

Thanks for the recommendation! will definitely pick some up for the overhaul, there is place in Toronto that sells a ton of ate stuff i think the type 200 is around 23$ a quart.

Hey guys I'm kinda having the same issue. Both my traction off and abs lights r on since yesterday there is no way to turn them off. I did my rear brakes today but it didnt help. My brake fluid is black. I changes my trans mount and end links last week but that shouldnt have any effects.

brettfavreisamonster wrote:

Hey guys I'm kinda having the same issue. Both my traction off and abs lights r on since yesterday there is no way to turn them off. I did my rear brakes today but it didnt help. My brake fluid is black. I changes my trans mount and end links last week but that shouldnt have any effects.

You have an ABS failure. Chances are, a Wheel Speed Sensor or the wiring is bad. Putting on new brakes will NOT turn off the lights....they have nothing to do with those lights. You need to have the car scanned for codes to see which wheel(s) is causing the failure.

Well a bad wheel sensor cause my speedometer to be off as well? For awhile now my speedometer doesnt go pass 65mph.

brettfavreisamonster wrote:

Well a bad wheel sensor cause my speedometer to be off as well? For awhile now my speedometer doesnt go pass 65mph.

Nope. Speedo has nothing to do with the Wheel Speed Sensors. The Speedo's input comes from the Transmission Output Speed Sensor, which is located on the passenger side of the trans. It's possible that the Instrument Cluster itself is screwing up on you as well.

Abaddon wrote:

brettfavreisamonster wrote:

Well a bad wheel sensor cause my speedometer to be off as well? For awhile now my speedometer doesnt go pass 65mph.

Nope. Speedo has nothing to do with the Wheel Speed Sensors. The Speedo's input comes from the Transmission Output Speed Sensor, which is located on the passenger side of the trans. It's possible that the Instrument Cluster itself is screwing up on you as well.

Thx. is the speed sensor something i can replace? Or do i have to replace the who hub? Thanks.

brettfavreisamonster wrote:

Thx. is the speed sensor something i can replace? Or do i have to replace the who hub? Thanks.

The Wheel Speed Sensor is part of the entire hub assembly....

EDIT: You need to have it scanned to see which wheel, or which component is causing the issue before you start replacing anything.

Okay, I have dealt with this issue with my Riv for about a year now. It started out as the Traction Control was off and I was unable to change that. Then about 6 months later I had the ABS light coming on every now and then and eventually it stayed on. I have read all the posts about the jumper needing installed on the drivers side fan, and once that is done to replace the Brake Control Module. Well after a long year of leaving the Rivi parked because multiple issue that seemed to arise back to back I listed below.............I looked at the connector on drivers side and it already had the jumper/adapter installed? It basically looks like a 5" extension cable right? So if this is the case why has my BCM gone bad or could it be something else?


Issue #1. Water Pump intake line on my series one began leaking so I parked it till fixed. They were still in decent shape but o-rings that fit and allowed it to pop back in were nearly impossible to find but I finally used little ones stretched way the hell over that fit the groove perfect. Re-filled and drove for a week or two before it over heated from a cracked radiator.......Let it sit for almost 9 months before I time and was tired enough of the wife's PT to buy one and install it.....Fixed.......Uh oh now it began cutting out under throttle. Damn parked again.......

Issue #2. After 3 months went to work on Rivi and the battery was so dead I couldn't jump start it. Battery took a shit after 11 Years! Thanks A/C Delco! Couldn't you have made it last 20 years? JK Hellava a battery to last that long. The first OEM battery lasted 9 Years (Tip: Stick with A/C Delco! or buy one every 3-5 Years)

Issue #3. Riviera will just stutter or shutter or start cutting out with any amount of throttle. Read about 300-400 post on Riviera forum suggesting everything from TPS, FPR, Coils, Wires, Plugs, and Vacuum Lines. Started to look into jerking/cutting out issue and started with a new TPS, then a new FPR and Next I filled car up with a bottle of SeaFoam, Octane Booster, and Fresh Premium Gas to see if maybe I had a KR issue because of water in fuel or bad gas. Disconnected battery overnight to let sensor and PCM reset. No change. Read about looking at plugs while the car is running in a very dark place to see a misfiring Cylinder. Behold the number 4-Cyl wire looks like a flux capacitor shooting a glowing Aura up the wire toward the plug. Replaced Plugs and wiring and that fixed the cutting out! Back to full boost and no hesitation   Oh no the Airbag light starts Flashing and I can hear a motor sound or pump sound revving up and down.......

Issue #4. Airbag Light flashing, Pump/Motor revving up and down and the dash light get dim the bright.......Read more post on Riv forums and found one about the Battery Thermistor going bad causing this issue......Unplugged Fude as recommended by Post and find the discontinued Thermistor at a junk yard. Found one and replaced....Fixed!!!!  Oh no the Driver Side Window won;t roll down.......

Issue #4. Drivers Side Windows won't go down. I hear the switch click but no movement by windows at all. Read Rivi Forums about taking door panel off and checking switch and Motor.. Took panel off and noticed the motors mounts has come a little loose and the motor was shifting about a 1/4 in. Tightened three motor mounting bolts and hit the down switch while I tapped the motor with the back of screwdriver and almost instantly it freed up and went down.......Fixed!!!! Oh no the passenger door lock won't open or close automatically..sounds normal and seems to move a hair but don't move all the way to lock or unlock tried both ways....Going to look at today lol.

I want to thank the moderators and member of this forum. This car was my wife's father's last car before he past away and he took excellent care of it. Hell he kept in the garage and drove it once or twice a week for 16 years before selling it to me in mint condition with 29K miles. Even with the few miles it had a lot of issues arose after a year of driving it and without these forums it would be collecting rust in the yard. Thank you so much guys and keep up the awesome work.