View Full Version : OT:95 monte carol abs problem

09-05-2010, 10:30 PM
replaced all the brakes roters and drums and a new back line, bleed the entire system several times replaced the sencors on the top of the abs unit bleed again, removed all the wires from wheel speed sencors and pluged back in , replaced the abs relay, checked the circut breaker and fuses are all good as well, dam ligght still wont go off ,

any ideas cause aim out of ideas, even tried to pull the battery and then reconnect and still the light stays on,

need help on this one, its a 1995 monte carlo 3.1 liter engine in it

in 2006 the abs module was repalced at the dealer

09-06-2010, 02:11 AM
You didn't mention whether you've been to the dealer, but some lights can only be reset using their diagnostic equipment (this is usually the case for airbag lights, not sure about ABS)


09-06-2010, 09:11 AM
I have worked on a few ABS systems of late and have just started to really educate myself on their specific electronic workings. I will say that ikdor is correct in that some systems will not turn an ABS light out without the proper scan tool.

I will take a guess and say that it has a Delphi Moraine ABS system on it. Some of these systems require that the ports on the ABS unit be bled out. But it can vary from the Delco III to the Delco VI.

Most of the time, if you didnt replace anything before the ABS pump, a simple bleeding procedure will get you up and running.

You may ask around and see if any of your buddies have an Actron ABS scan tool ($100) or a Innova 3160 ($250+) scan tool. The Actron will tell you why the ABS light is on and allow you to turn it off while the Innova 3160 is supposed to allow you to run the ABS pump and perform other operations to troubleshoot the system.

Find out what make and series of ABS system you have and I'll see if I have some more information on it.


09-06-2010, 01:06 PM
Is just the ABS light on?
Is the brake warning or e-brake light is off?
Was everything ok before the bleeding procedure?

09-06-2010, 11:08 PM
95% of the abs problems I see on GM cars are broken wires going out to the wheel speed sensors. Usually can be found by taking the wires out of the plastic protector. Sometimes gently pulling each wire will find the wires broken inside their insulation.

09-07-2010, 09:23 AM
Is just the ABS light on?
Is the brake warning or e-brake light is off?
Was everything ok before the bleeding procedure?

the abs light was on before hand as the car had a broken brake line so we fixed it rebleed the system.light stayed on, only the abs light, so we bought a code reader had to use the 1993 monte setup and we cleaered the code a wek elater it came back tried to even rebleed everything, the kid tool the reader back told him to keep it, any how tried pulling hte battery no luck its still on tried re plulling the sencor wires again and plugging back in, even changed the 2 sencors or whater ever they areo n the ABS module, re bleed and still the light is on, ,we have to get this thing normal or its not going to pass the safty when it goes in,,

going to have to buy a new code reader iam sure of that, but also there is still gota be something stuiped i just havent seen yet

09-07-2010, 10:46 AM
I'm not completely familiar with the abs system on your Monte Carlo so take this advice as just a suggestion.

But I'm thinking the abs light came on because it was triggered when your car's brake line leaked causing a pressure imbalance in the system. This is indicative of a failure in either the front or rear portions of the brake system. The pressure imbalance switch, which is located neat the master cylinder, would then light the brake warning light.

This switch is basically just a hydraulic spool valve that is normally centered, when a pressure imbalance occurs in the system the spool moves to the low side triggering the light. In order to recenter the valve one has to bleed the opposite side of the system just enough to recenter the spool in the pressure imbalance switch.

Rookie machinist
09-07-2010, 11:49 AM
IF memory serves me correctly the accumulators used to fail on theese, be careful if you have to replace it. If you remove it while it is charged you it will fly off like a rocket.

09-07-2010, 02:19 PM
i replaced the 2 sencor thingys on the abs Module,and rebleed everything and i even tried today to take the batterty off line for an hour and still the dam light wont go out , so its time to get the proper scan tool , turns out its needed to reset the system when work is done on the abs,iam just galde its my sons car not mine ifit was my car i would have taken it out to the feild and destroyed it by now..lol.. oh well i guess ill give him the news tonight, 400 bucks for the scann tool. and if we do need sensors well its not going to be cheap and the price of the module doubled in the last 4 years sence it was last done,

to bad these were not recall issues ..

09-07-2010, 11:21 PM
ok after a huge pile of research today , god i hate reading, anyhow turns out there are only 2 scanners under 2000.00 that can read and do the job for this car, and one scanner for 400 bucks that might work, so we start cheap withthe 400 dollar scan tool.. anyhow this car must be reset with the scan tool when messing with the brakes perioed, thank god my G5 does not have ABS ... but this monte oh well, so this saturday while its a nice day again for us ill be starting with taking wires off and looking for broken wires, and starting there for repairs before we get the scann tool.. took the battery off line for an hour today and that made no difference. the caris not yet been certifed so payinga tow truck to a garage is out of the question just to pay 80 bucks to have it scanned , besides i can increase my own business if i have a scan tool .. so its not like its not going to get used...

we do have access to all the abs stuff for what ever we need if we need more parts for the abs system , so thats good news for now..

09-07-2010, 11:49 PM
ok after a huge pile of research today , god i hate reading,
and you think YOU got it bad.....

09-08-2010, 12:38 AM
and you think YOU got it bad.....

OMG i forgot to laugh