10th Jun 2003, 16:17

My 99 Silverado extended cab has a gurgling sound coming from under the dash (air bubbles in the heater core) upon acceleration. Anyone else have this problem? The service 4WD light just came on. What do I have to look forward too?

16th Jun 2003, 08:20

I own a 1999 Chevrolet Silverado as well, with only 53,000 miles. I, too, just had the ABS unit go out in my truck. I called Chevrolet to complain because of reading all these complaints and also having a friend with the same problem. This $1,000 repair bill is ridiculous! GM doesn't want to own up to the problem because it would cost them too much money to recall. Let's just hope enough people send in their complaints so that we can get our money refunded by GM if and when they send out a recall.

16th Jun 2003, 14:02

My 1999 Silverado at 60,000 miles has had the same problem. In fact the dealership told me there has been so many problems with this part they are having to keep it stocked every week. Chevy has a responsibility to recall this problem that is costing apparently thousands of people an average of $800 to $1000 to fix.

19th Jun 2003, 02:11

I repair these ABS modules.

The following should answer all your questions regarding the ABS failures.

The pump motor is switched on by a FET transistor in the ABS control unit. The FET is like a relay, only there are no moving parts.

Just as a mechanical relay can be plagued with "welded contact" failure, the FET transistor does the same. Essentially the FET in all your guys' ABS control boxes are shorted... making the pumps run continuously. The computer however is still perfectly good. Just needs the FET replaced.

There is a conventional mechanical relay in the ABS control unit as well, but it is part of a low current "snubber" (voltage spike absorber) network and ABS solenoid power rail enable. This relay is not problematic in the GM ABS modules. Just the pump motor FET.

The FET is a 3 dollar part. Don't replace the entire ABS pump/controller unit because of that.

For $100 (you also pay two way shipping and insurance), I will replace the FET in your ABS control unit and guarantee the work defect free for six months. It is about a four to five hour job to replace the defective part.

The ABS controller housings are silicon sealed and difficult to take apart without damaging the circuit board inside. There are also 30+ connections that have to desoldered to remove the circuit board to gain access the FET.

Some precautions to protect the ABS pump motor FET. NEVER jump-start your vehicle or another's.. no matter what the manual says. Never use a battery booster to assist a weak battery to start your vehicle. Also be careful of static electricity when the battery is disconnected and working under the hood. When the battery is out of the vehicle, short the positive battery lead to the vehicle's chassis. This will protect the FET from accumulated static discharge if you reach out and grab the battery terminal.

Doing any of the above may subject the FET to abnormal voltages which decompose its internal junction leading to failure and shorting.

Static discharge from your body into the + battery terminal will also break down the FET's junction over time ultimately leading to failure.

Contact me for further info:


Gavin Curtis

Circuit Solutions

1004 Stanford Rd PO BOX 153

Deary, ID 83823.

25th Jun 2003, 14:50

I just had the same problem on my 99 Chevy with 49K miles. I agree that Chevrolet should own up to the problem. On top of calling Chevy to voice your opinion, what everyone needs to do is go to the following website and file a complaint with the NTSB (National Transportation Safety Board) in order to push Chevrolet into a recall. It will take between 5 and 10 minutes, but if enough of us do this, we are more likely to get a recall. It is very easy just go to file a complaint and fill out all the information, including your VIN number. Please pass this on to as many people as you can find at other boards.



Atlanta GA.

25th Jun 2003, 20:58

I am also an owner of a 1999 Silverado with a faulty ABS module. The repair was quoted to me as $891 bucks! I have 110000 miles, but my guess is this is probably the second ABS module for this rig. Yes, I think GM slipped up with this invention. ABS is fine on dry roads, but it is terrible on ice. I know first hand how the ABS failed to stop me on ice. It ain't funny GM.

I will also call the number listed and complain.

6th Jul 2003, 15:07

To say that I am UNHAPPY after reading these comments would be the understatement of the century... I just drove 250 miles to "rescue" my college-aged daughter because she heard this "humming" from under the cab, with the ABS light on. I disconnected the 60 amp fuse so I could get it home, and now I am finding out that it will cost 800-1500 to fix it!!!???!?! This is absolutely unbelievable and unacceptable! From the number of comments it is apparent that GMC has a serious problem they need to attend to. Further, I am "stuck" with it, as I can't sell it with the pump motor running, and I can't sell it with the ABS/Brake light on. Not good... I long for my simple 2-wheel drive Ford...12 years, same battery. Changed the water pump twice, headlights a few times, a tuneup here and there...

16th Jul 2003, 05:45

Hey me TOO!!! The ABS pump on my 99 Chevy Truck went out almost two years ago. I refuse to give someone $1000.00 to fix it. I am waiting for a GM recall. PS-I am waiting to win the lottery also. West, TX.

21st Jul 2003, 10:28

I have a 2001 GMC Yukon XL with the same problem at less than 45,000 miles. Haven't attempted to get it repaired yet since all the dealerships in my area are backlogged for over a week. I've just disconnected the ABS control module under the car to revert to normal brakes.

26th Jul 2003, 17:08

I also have a 1999 Chevy Silverado (Less than 32000 miles, purchased new). Within the past 45 days, I have had to have the distributor cap and rotor replaced (which the mechanic at the dealership indicated was a common problem with that particular engine). I then had to have the fuel pump replaced at a cost greater than five hundred dollars. and then had the ABS module problem that has been described in this thread. The first two incidents occurred away from home and were repaired by a Chevrolet dealership, but the ABS module failed around town and after having the diagnostics performed by the dealer from which I purchased the truck and getting no satisfaction, I took it to a local mechanic that I trust and paid him the one thousand dollars for the repair. While doing some work at a doctor’s office, I was telling one of his employees that drives a ‘99 Silverado of my problems and she told me that she had experienced an ABS module failure, but was able, after much argument, to get the dealership to replace it under warranty.