ABS and Brake light come on randomly

[lukeman]

Hi folks,

I need some help, please see my problem below:

MODEL:2000 Astro Van AWD

SYMPTOMS:

ABS and Brake light came on randomly about a year ago, they normally would come off after turn off the engine and restart again, sometimes restart did not get rid of them. The brake and ABS all worked normal when the lights were on. There has not been any obvious reason found for the symptom (like some others said "hit a bump" something), it just came randomly and intermittently. A year ago this started but happened not that often, but recently this problem comes more frequently, especially when the weather is wet.

The interesting thing is, every time when the ABS and brake light came on, I kept them on and plugged in the OBD reader, there was no code detected, but when I refreshed the reader and scanned again, the ABS and brake light just came right off.

I am not good at the wiring or electrical stuffs, but hopefully I can get some idea about what problem that possibly will be.

Thanks for reading.

[Corsemoto]

The search function is definitely your friend on this one. Search "EBCM repair" or "ABS module repair"

Is your OBD tool able to read ABS codes?

[lukeman]

Yes, there is a ABS section on my OBD scanner, but there is no code detected.

[lukeman]

Update:

Just changed the front brake pads, not the rotors, and sprayed some solvent around the speed sensor on both sides as I had seen they were quite rusty.

Had not expected any better on the ABS and Brake lights, but it was so weird, since the brake jobs were done, those damp lights never come on again, it has been about two weeks now. They normally will come on after 5 minute drive or sooner.

I am thinking the sensor(s) have not been grounding or connecting well since the rust around, or the old pads worn too much causing any problem related to illumination.....who knows? Any idea?

I almost wanted to remove the EBCM to check.

[zzimmer3]

I don't know if you've cured the problem, but there is a very descriptive thread on a way to fix those lights. Mine does the same thing, according to the thread topic, its a connection issue under the dash and requires removing the unit and re-sodering some connections or pins on a circuit board. I glanced at the thread, but decided to deal w the sporadic lights coming on. But, maybe your issue was different and its now better?.?. In any event, good luck!

[lukeman]

I don't know if you've cured the problem, but there is a very descriptive thread on a way to fix those lights. Mine does the same thing, according to the thread topic, its a connection issue under the dash and requires removing the unit and re-sodering some connections or pins on a circuit board. I glanced at the thread, but decided to deal w the sporadic lights coming on. But, maybe your issue was different and its now better?.?. In any event, good luck!

I can't say my problem was solved, but just another lead to find out what happened. There is a video on Youtube that the guy fixed the similar problem (ABS and Brake lights on plus C0265 code) by simply reconnecting the ground wire of EBCM which is under the rad.

I will give mine some more time to see further.

[lukeman]

Hi folks,

Does any one know where the ground spot of EBCM connected to the chassis? The brake and ABS lights still came on but a lot less often then before, I am thinking tracing the ground of EBCM to see any loose there.

Thanks.

[Lumpy]

Don't waste time troubleshooting and trying to diagnose existing grounds. Install new grounds.


Lump

[The Drummer]

i seen on you tube that cleaning the ground thats in front of the batterie by the radiator as solve intermitent lights (abs and brakes) ,quite easy to do and wont hurt if there s any rust but dont solve the problem .

[lukeman]

i seen on you tube that cleaning the ground thats in front of the batterie by the radiator as solve intermitent lights (abs and brakes) ,quite easy to do and wont hurt if there s any rust but dont solve the problem .

Yes I have seen that youtube video too. That is why I will have it a try before open up the EBCM. But I did not see any ground spot around or under the radiator, is it a bundle of wires or just one? Thanks.

[Lumpy]

... I did not see any ground spot around or under the radiator, is it a bundle of wires or just one? Thanks.

Follow the ground cable from the battery to where it bolts to the metal support.


Lump

[lukeman]

... I did not see any ground spot around or under the radiator, is it a bundle of wires or just one? Thanks.

Follow the ground cable from the battery to where it bolts to the metal support.


Lump

But you have to find out which one is the ground of EBCM. The chassis got so many ground spots, just under the hood I had clean 3 or 4 of them which caused multi gauges on the instrument cluster not working properly. My brake & abs light problem is quite similar as the one showing on the following video, but my 2000 astro 4wd did not seem to have that ground wire under the radiator.

https://www.youtube.com/watch?v=ZgZdXH2zR8c

[Lumpy]

... I did not see any ground spot around or under the radiator, is it a bundle of wires or just one? Thanks.

Follow the ground cable from the battery to where it bolts to the metal support.


Lump

But you have to find out which one is the ground of EBCM...

Try and make this as complex and involved as possible. It's important to the electrons.


Lump