ABS AND BRAKE light

The abs and the brake light will light up for .4 seconds and my 2004 Jetta TDI will beed high-pitch 3 times at me.

I checked the brake fluid and it was good, I checked the fused and it was good.
faulty ABS sensor? or faulty wiring?

Most likely there is a stored code. Get it scanned with VCDS and post your findings here.

Other way will just be throwing darts in the dark.

VCDS may or may not show anything, I'm chasing a similar issue on my Beetle and there are no codes.

ABS fault should have a code stored.

how old is the fluid, how often has it been flushed/changed, how old are your brake pads and the depth of pad?
Possible culprit would be the sensor for the ABS ring or the wire harness for it.
Your ECU should store a code for any reason for a light like that.
You dont need VCDS, go to autozone and use the code reader or any code reader you like from amazon etc.... VCDS lets you do things, if you just need to read a code and clear, you dont need a $350 cable and software.
Cheers.

I was going through the same issue with mine. I ignored it for a year, and eventually the car wouldn’t start unless I touched the negative terminal. I cleaned the grounds underneath the battery and haven’t had an issue since.

Mongler98 said:

how old is the fluid, how often has it been flushed/changed, how old are your brake pads and the depth of pad?
Possible culprit would be the sensor for the ABS ring or the wire harness for it.
Your ECU should store a code for any reason for a light like that.
You dont need VCDS, go to autozone and use the code reader or any code reader you like from amazon etc.... VCDS lets you do things, if you just need to read a code and clear, you dont need a $350 cable and software.
Cheers.

Click to expand...

Generic OBD2 code readers only read emission DTC's. Since the AutoBone scanner does not read ABS codes, there are none stored, right?

Brake fluid and pad wear are irrelevant. He needs a scanner (VAS or VCDS) that will actually read ABS DTC's which AutoBone's scanners do not. With a compatible scanner (VAS or VCDS), he could monitor the ABS sensors for proper signal in measuring blocks if an ABS DTC is not set.

And that's where the car manufacturers really bent us over and railed us vigorously. Only OBD2 emission DTC's are required to be reported by the ECU so any codes other than emissions do not report through the Check Engine Light or are readable by a generic OBD2 scanner.

Mongler98 said:

how old is the fluid, how often has it been flushed/changed, how old are your brake pads and the depth of pad?
Possible culprit would be the sensor for the ABS ring or the wire harness for it.
Your ECU should store a code for any reason for a light like that.
You dont need VCDS, go to autozone and use the code reader or any code reader you like from amazon etc.... VCDS lets you do things, if you just need to read a code and clear, you dont need a $350 cable and software.
Cheers.

Click to expand...

Stop trying to help, you're not.

OP: OBD works, you need to start there, with an appropriate scan tool that can display the DTCs stored in the ABS controller, OR verify the ABS controller is actually even working.

VCDS helped me with the same issue. Turned out to be a faulty clock spring. Another time was a chewed up right front ABS cable. VCDS is the only way to turn off the ABS light.

old fluid in most cars especially with copper lines can wreak havoc on an ABS system

if you had a brake pad that was busted up or issue with breaking in general the mechanical side of the caliper, the ABS can detect this and turn on that ABS light

ABS works off of a sensor and a rotating ring usually on the Hub or CV Axle. lots of users have a light come on when the wire for this sensor goes bad, in fact i remember there being a thread not to long ago about someone who had a mechanic break the wire on this sensor.
Some ABS systems have wear sensors in the break pad its self. in older cars the ABS light would be triggered by this.

I never said you could do anything other than read and clear codes with out VCDS. so get off my back.
I asked what has been done to upkeep the car and you jump on my back.
I have a Kobra OBD scanner and i use it on VW, ford, honda etc... and have always been able to find codes on ABS issues.

Dannyboy said:

ABS can NOT detect mechanical faults on mechanical side, it can only detect if the wheel is moving/receiving a signal properly.Only ones that can are the electric assisted brakes which I'm pretty sure no 2004 model ever came with.
I've had alot of work on ABS systems mostly wabco, bendix, haldex and bit of ATE. 3 main problems are-
1. Loose bearing causing tone wheel to read irregularly
2. Corroded tone wheel
3. Sensor damage/water ingress in harness connector/ harness damaged
I agree with the guys that say use VCDS, scan ABS controller
and get the code. Then go from there

Click to expand...

top kek, you have never had a valve assembly go bad or get gummbed up, the ABS light will 100% go off if the valve body is not working right.

the worst ABS system i have ever worked on was on a 1995 chevy G30HD, brake fluid was never changed, i kid you not that the brake fluid was as viscus as cold sludge motor oil and took 6 flushes over 1 every week to get most of it clear.