ABS Head-Scratcher

[Guest]

Well, I only THOUGHT I cured the ABS light. In the morning or when it's below 83 degrees or so outside, the ABS light goes off after the initial pressurization. As the outdoor temperature goes up, the light goes on and stays on. If the car is cool, but it's hot outside, the light stays on. I have replaced both ABS relays under the hood and used the manual to check the operation of the brake fluid level switch and pressure switch (pressurized and depressurized) once the ABS light was on. Both switches were OK, as was the wire connecting the two. I pulled the diode from the trunk and put it in the freezer for a minute to see if the temperature change affected the ABS light. Nope...still on. Interestingly, I found an old cassette tape from the car's trip to the dealer a few years ago. The technician mentioned a "9/10" problem from the EBCM (pressure/level switch loop that I tested) and said he wasn't sure what caused it, but if it continues, they may want to try replacing the EBCM ($$$) to "see if that works". With no confidence in them, I'm asking for any ideas from you guys. Otherwise, it's the status quo.

[Guest wally888]

My ABS light has been on and off for over a year.Was on most of the winter but when it got hot in Ga. it started going out most of the time.Now it's hotter and it seldom goes out.Think we can forget any correlation re.<BR>temp.<BR> Last person to attempt fix thinks a groung up under dash may be cause. I think main relay but so far have not checked.Brakes and anti-lock work fine w/ or w/o light on!<BR> No codes at pin box-checked rotor sensors and wires to relays,press. switch,fluid level sensor??????????<P>------------------<BR>Definition of an expert: An ordinary guy called in from out of town!

[Guest]

Hi,<BR> My 1991 Riviera, has had the ABS light 'on', can someone please tell me how to check for the ABS codes?<BR>I am not sure as to what had happened, but the car had gone in for replacing the brake pads and the next thing I noticed is that the brakes were not the same any more, as although the ABS light was off, so was the ABS, somehow some repair man must have removed the ABS light Code,without fixing the actual problemn (I am told that the car needs a new caliper at the rear,'cose the bleed screw is broken hence there may be air in the system causing the ABS problem but the ABS wasn't operating , only had the power brakes).<BR>So far, now the car has been standing in the garage for almost 6 months, without a battery and after replacing the new battery,the ABS light has yet come 'on' and stays 'on' and the same deal only the power brakes no ABS. I tested this on a skid pan, and indeed there was no ABS.<BR>What can I check, please help.<P>many thanks and have a great day<P>Prakash<BR> <p>[This message has been edited by prakash raja (edited 08-06-2000).]

[Guest wally888]

After taking R to have several small repairs,one of them the intermittent anti skid light on,and getting a long story about a ground wire up under dash,bla, bla ,bla and $55 for the analysis(spent $60 on "replace accumulator" and if had not done myself would have been another $150)<BR> I decided to take some info I received on this board ,get in the Ga. sun and fix the damn thing.<BR> Previously I had cleaned all 4 wheel sensors,bled the brakes,replaced the accumulator(GM mech insisted it was bad)played around in the trunk w/ the module,disconnected the diode..........<BR> So I switched the main relay(hood open,face windshield,see 3 black boxes on firewall left of accumulator,main is one on right)(to remove gently pull down and after it is free hold little clip down while using small screwdriver to gently seperate the 2 pieces.-all 3 relays are the same)( 1989) w/ the one next to it and at 1st check the light stayed off during 3 starts and ign. off then both lights came on (think the bad relay was placed in pressure sensor) so I bought a new relay from Auto Zone and all is fine.$8<BR> If you have lights on buy a relay and try switching before you spend big bucks for remove and replace fix! and learn the proper way to add brake fluid. <P>------------------<BR>Definition of an expert: An ordinary guy called in from out of town!

[Guest wally888]

Duane-Thanks for posting test results on board in article "Test Results".<BR> If others would do so maybe we could draw some conclusions but comparing yours to mine:<BR> Times and pumps indicate(suggest!) your pump gets the presure up ok,accumulator seems ok but the pump may be going bad-slow to build pressure,wearing out,internal leak or??Invite others to comment!<BR> The strengh of the pump would ,I think,effect time to rebuild pressure.<BR> And in some way this may influence to yellow light's intermittant coming on. Experts,lets hear from you?<BR> I was concerned when I discovered I could make red light come on w/ pumping pedal even tho pump was running then someone on the board said that was normal and in manual.So far I haven't been able to find that in the manual.Where?<P>As readers can see I am trying to stimulate interest in preventative maintenance on brake system by asking members to check their brakes i/a/w item in "Brake Problems"<BR>on the board but is drifting to 2nd page fast!Seems that would be more interesting than a kid from N Y and his Reatta!