Now what!!!???? ABSinop & TCS off Lights are on.

**jrbonds** · 06-28-2011, 08:09 AM

Ok, so the ABSinop & TCS off lights come on intermittedly, starting last week.

Last week had a issue with the aftermarket alarm spazzing out (and I don't even use the thing). Seemed to correct itself and quit.

I seached and read a bunch of different stuff, but none of it fit.

So could the alarm cause this? or

Could my bald tires and bad alignment cause this? or

Could it just be a grounded out wire? or

Bad 02 sensors wreaking havoc on wiring stuff or car in general???

I hate wiring and electrical problems. Hate it hate it hate it.

**cammed goat** · 06-28-2011, 10:14 AM

Could be a number of things.

BCM
Dirty MAF
Speed sensor out of range or not operating at all

**jrbonds** · 06-28-2011, 10:16 AM

Originally Posted by cammed goat

Could be a number of things.

BCM
Dirty MAF
Speed sensor out of range or not operating at all

I have a MAF code that popped up when my dad scanned it a couple months ago when the check engine light came on, 02 sensors where the other codes. I bought the MAF cleaner and cleaned it, but never rechecked the code.

**98maro** · 06-28-2011, 10:18 AM

Mine have the same problem,
Speed sensor
And abs block.
I replaced the speed sensor. And the lights still on
I guess the problem is the abs block.

Get it scanned

**jrbonds** · 06-28-2011, 12:14 PM

ABS block?

I'll have to search that. I'm going to change the O2 sensors before I rescan anything. So I guess I will have to wait.

**JayTA98** · 06-28-2011, 12:40 PM

I will suggest you to clear your codes. This will pop your current codes and will eliminate the ones that were fixed in the past. It's less confusing.

**jrbonds** · 06-28-2011, 12:47 PM

Originally Posted by JayTA98

I will suggest you to clear your codes. This will pop your current codes and will eliminate the ones that were fixed in the past. It's less confusing.

Ok. How do I clear the codes? I swear I read something about this the other day but cannot find it now.

**JayTA98** · 06-28-2011, 12:58 PM

Originally Posted by jrbonds

Ok. How do I clear the codes? I swear I read something about this the other day but cannot find it now.

Some people just disconnect the battery for like 10 mins but I prefer to do it with a scanner. Most auto parts places read your codes for free and reset the light.

**jrbonds** · 06-28-2011, 01:02 PM

Originally Posted by JayTA98

Some people just disconnect the battery for like 10 mins but I prefer to do it with a scanner. Most auto parts places read your codes for free and reset the light.

Ok, thank you!

**SSwt00SS** · 06-28-2011, 01:35 PM

my money is on one or multiple faulty speed sensors. A normal OBD II scanner, I do not believe will read the codes (not 100% on that though). I have a f-body guy at a dealership I go to bring out a special scan tool to let me know the front passenger side spped senor was bad, that was not an OBD II scanner. I have one of those and it didn't pull the code, which is how I ended up at the dealership.

I got under the car, pulled the front tire off and saw that one of the wires had rubbed and frayed itself on the side of the frame all the way through. the speed sensor cables are discontinued for our cars, so I took the whole cable to the dealership where we were then able to match the connectors to one they had in stock. I bought it and spliced the two together and sealed them. Plugged it in and no light since then. It was a $20 part.

My guess is that since both TCS/ABS are on it could be a rear one. Good luck.

**cammed goat** · 06-28-2011, 02:51 PM

Originally Posted by SSwt00SS

my money is on one or multiple faulty speed sensors. A normal OBD II scanner, I do not believe will read the codes (not 100% on that though). I have a f-body guy at a dealership I go to bring out a special scan tool to let me know the front passenger side spped senor was bad, that was not an OBD II scanner. I have one of those and it didn't pull the code, which is how I ended up at the dealership.

I got under the car, pulled the front tire off and saw that one of the wires had rubbed and frayed itself on the side of the frame all the way through. the speed sensor cables are discontinued for our cars, so I took the whole cable to the dealership where we were then able to match the connectors to one they had in stock. I bought it and spliced the two together and sealed them. Plugged it in and no light since then. It was a $20 part.

My guess is that since both TCS/ABS are on it could be a rear one. Good luck.

Snap On scanner? I used a SOLUS for mine. Read the system like a champ.

**SSwt00SS** · 06-28-2011, 03:08 PM

No, not a Snap-On, but I'm not at the house to look it up the make.

I guess I should say that the scan at the dealership was free for me. It pays to have connections I guess!

**JayTA98** · 06-29-2011, 12:09 PM

Originally Posted by SSwt00SS

my money is on one or multiple faulty speed sensors. A normal OBD II scanner, I do not believe will read the codes (not 100% on that though). I have a f-body guy at a dealership I go to bring out a special scan tool to let me know the front passenger side spped senor was bad, that was not an OBD II scanner. I have one of those and it didn't pull the code, which is how I ended up at the dealership.

I got under the car, pulled the front tire off and saw that one of the wires had rubbed and frayed itself on the side of the frame all the way through. the speed sensor cables are discontinued for our cars, so I took the whole cable to the dealership where we were then able to match the connectors to one they had in stock. I bought it and spliced the two together and sealed them. Plugged it in and no light since then. It was a $20 part.

My guess is that since both TCS/ABS are on it could be a rear one. Good luck.

you are correct an OBDII only scanner will not read the ABS codes. I was thinking about the MAF code that she mentioned. They are some OBDII scanners out there that read ABS codes but are expensive.

**jrbonds** · 06-29-2011, 01:22 PM

I just don't know, I've checked everything I can. Those lights just come and go as they please. I'll figure it out eventually.

**Deviant LS1** · 06-29-2011, 01:27 PM

Sounds like a malfunctionung ABS module. When the light comes on get it scanned with an ABS scanner.

**jrbonds** · 06-29-2011, 01:29 PM

Originally Posted by Deviant LS1

Sounds like a malfunctionung ABS module. When the light comes on get it scanned with an ABS scanner.

Ok will do. I hate lights on the dash.

Are ABS modules expensive?

**cammed goat** · 06-29-2011, 06:18 PM

You could check out GMPartsDirect or Ebay as Ebay tends to have New Old Stock parts for cheaper than the dealership.

**Deviant LS1** · 07-01-2011, 06:32 AM

I had a similiar problem where the BRAKE, ABS/INOP, and TRAC OFF light would come on randomly. Then they would go away after I restarted the car. At first it would only happen once or twice a month. Then it started coming on every few driving cycles. The next time the lights came on I drove straight to my friends shop who has an ABS scanner, I didn't shut the car off and I let him scan the codes. One code was for ABS malfunction and the other was for ABS electronic malfunction.

You need to get the codes scanned to make sure you're replacing the correct parts. If you do need a new ABS module then look for a ABS module or EBCM (Electronic Brake Control Module). It needs to be for your channel car. If you have a three channel ABS car you need a three channel EBCM, if you have a four channel ABS/Trac car then you need a four channel ABS/Trac EBCM. They are not interchangeable.

I bought a used "known to be good" EBCM for $100shipped. You can find them used on Ebay from $50-$150. I believe the whole job from the dealer costs about $1500. The complete EBCM new is quiet expensive and bleeding the brakes after replacing it requires a TechII as you need cycle the ABS valves to properly bleed it.

The EBCM is made up of two parts. One is the ABS block that contains the ABS valves and that your brake lines run into. The other is the ABS electronic controller. It's the electronic black box that attaches to the ABS block. It's pretty common that the controller fails before the actual ABS block does. It can be replaced just by undoing six torx head screws.

I only replaced the electronic part and all my issues are gone.

**99pewterta** · 07-03-2011, 08:08 PM

Originally Posted by Deviant LS1

I had a similiar problem where the BRAKE, ABS/INOP, and TRAC OFF light would come on randomly. Then they would go away after I restarted the car. At first it would only happen once or twice a month. Then it started coming on every few driving cycles. The next time the lights came on I drove straight to my friends shop who has an ABS scanner, I didn't shut the car off and I let him scan the codes. One code was for ABS malfunction and the other was for ABS electronic malfunction.

You need to get the codes scanned to make sure you're replacing the correct parts. If you do need a new ABS module then look for a ABS module or EBCM (Electronic Brake Control Module). It needs to be for your channel car. If you have a three channel ABS car you need a three channel EBCM, if you have a four channel ABS/Trac car then you need a four channel ABS/Trac EBCM. They are not interchangeable.

I bought a used "known to be good" EBCM for $100shipped. You can find them used on Ebay from $50-$150. I believe the whole job from the dealer costs about $1500. The complete EBCM new is quiet expensive and bleeding the brakes after replacing it requires a TechII as you need cycle the ABS valves to properly bleed it.

The EBCM is made up of two parts. One is the ABS block that contains the ABS valves and that your brake lines run into. The other is the ABS electronic controller. It's the electronic black box that attaches to the ABS block. It's pretty common that the controller fails before the actual ABS block does. It can be replaced just by undoing six torx head screws.

I only replaced the electronic part and all my issues are gone.

is the electronic part of the abs sold separately or is it sold as a whole. i have the exact same problem and i bet its the electronic part. do you have a part number

**35th-ANV-SS** · 07-03-2011, 08:18 PM

Jodi,

Do you have the same size wheels on the front as back? You haven't changed tire size recently have you?

As an FYI, if your ABS light goes on, your TCS light will come on automatically. TCS cannot operate properly without ABS.

I bet if you fix the ABS issue, your TCS light will also shut off.

I had both lights on in my car after the install of the 9". It ended up being a pinched wire. I would strongly consider checking the wiring first. Trace it all the way from the speed sensors at the wheels. I would also check to ensure all the harnesses are plugged in and clean. Sometimes the rear wheel speed sensors get gunk'd up with debris and grime.

With a proper scanner (I used a snap-on from a mechanic), you can data log the speed sensors and they will show you what each wheel is moving in MPH. The wheel that stays at 0MPH is the faulty speed sensor, assuming it is indeed a speed sensor that is bad.

Keep us posted.