kadeer

Would really appreciate your expertise and help, I have developed a problem in the car, seems it hesitate(may be turns off) for a second while on the hwy.
The warning light flashed with the ABS for a second and goes away. Repeats every minute or so.

What should I check for: Air filter, fuel filter, Comp Chip, new gas ??? Battery connection seems ok.

Any idea, what could be my problem or any of you encounter such problem before.

Thanks in advance.
_Kadeer

993chaz

I had the exact problem in my car, turned out to be a ground strap that had come lose.

Jeff 993TT

Sounds like a battery problem to me too. I had similar abs/abd warning lights when my alternator belt broke. Those abs/abd lights are sensitive to voltage ( or lack of voltage ).

Jeff

kadeer

Jeff/993Chaz, Thanks will look into it.

Btw, where is the ground strap, is it attached to the battery, the terminals are secure when I checked.

Jeff 993TT

Check how the negative cable is secured to the car chasis, not just how the terminal cable is secured to the battery.

Jeff

993chaz

Its attached to the chassis.

993chaz

OOPS, sorry Jeff got it already!!

kadeer

I just checked it, the battery cables are secure to the chasis.
It does not seem like the car hestitates when there are bumps, because I am in NY and I hit pot holes constantly in my drive. Making me believe that its not loose wires.

I notice the warning light blurbs even on a smooth drive. But it does not stay on.
Any more idea?

Thanks, Kadeer

Knute

There is a well written DIY repair for a fault in the clock module that addresses a fault similar to that addressed above- if the airbag circuit sees low voltage, it gets unhappy, and part of that circuit is on the clock module...

I know you're asking about ABS and not the airbag check system, but it seems plausible that your problem could be a similar type of faulty connection in the the associated gauge cluster.

See: <a href="http://p-car.com/diy/clockrepair/" target="_blank">http://p-car.com/diy/clockrepair/</a>

On the other hand, if the whole car is actually "hesitating", it does sound more like a core grounding problem as others have suggested, and the ABS warning light is just a secondary symptom.

Good luck!

-Knute

kadeer

This might be relevant, 2 days ago I took the car to a car wash, its cold in NY, and not sure if that is the cause.
Basically, the car misses and the warning light comes on for a half a sec and goes away with a flash.
I was thinking of putting Techron in the tank, I have never done it before.
I also noticed the the light came on when I was stationary after I reved the car several times.
Could not get it to repeat in any pattern.

tom_993

Hi Kadeer,

There are a few other connections for the ABS system you can check. Open the trunk and remove the spare. Near the battery, you’ll find the ABS “hydraulic unit” (under a black plastic cover). There is a big electrical connection to it. Unplug it and plug it back in a couple of times to clean the connections. There is also a ground wire. Loosen its connectors, wiggle the wire around a bit, and then retighten. On the other side of where the spare sits, you’ll see the “control unit.” This is a computer unit similar to the ECU. Unplug and plug its connector a few times.

You can also check and clean the wheel speed sensors. Remove each wheel and look around a bit. See the part with the fuzzy afro of metal particles? This is the magnetic wheel speed sensor. Remove it and pull it out of its hole. If you look down the hole, you can see the toothed wheel that rotates at wheel speed. Clean the debris off the magnetic end of the sensor (the end that goes near the toothed wheel).

I was faced with a similar problem. My ABD and ABS lights were coming on at random. Since they came on when I was not pressing the brakes, I reasoned it was an electrical problem and not a mechanical or hydraulic problem. I did everything I mentioned above, and the lights have not come back. I still have my fingers crossed, though… In my case, the ground wire on the hydraulic unit wasn’t real tight. It wasn’t real loose either, but just loose enough to make me suspicious.

Oh yeah, about the ABS and ABD lights coming on when the alternator belt breaks. I learned (from an expert) that this is deliberate. When the computer detects that the alternator is not charging, it purposefully disables ABS and ABD (I guess they require too much juice?). The lights come on to alert you to this fact.

Good Luck!

Tom
’95 993

Edit: Yes, put some Techron (or the Lubro Moly stuff) in the tank. What are you waiting for?

Jack Ennuste

Kadeer

I had twice almost similar problem

1. First time water got into my boot and ABS unit connector was wet. It is located in the forward lower corner, in the other corner is battery. As water conducts elecricity it caused malfunction both ABD and ABS.

2. Second time alternator belt jumped off (yes, weird!). ABS and AMD lit and battery light either. So it can be also alternator related.

kadeer

Tom/Jack, thanks for the info.
I re-attached the battery cables and reved the car a lot and cleaned the air filter. The light has not appeared since, I am not sure if it was the water that got in after the wash and dried or the above things helped.
If it reappears again I will do the steps you all outlined.

Regards,
Kadeer

acrabtree0536

I love it, a few minutes online and I've solved my problem. Didn't think to look in the engine compartment. Alternator best was shredded.. Easy fix..