From 1999 through 2006 GM manufactured millions of sports utility vehicles (SUV) and trucks with Kelsey Hayes anti-lock brake modules. These units have a peculiar fault. When they fail the ABS light comes on and the pump often starts running continuously, even with the key off.
For no apparent reason, the ABS light will come on. There may also be a strange humming noise coming from under the hood. Turn off the key and the noise continues. The anti-lock brake (ABS) control module has failed on a General Motors SUV or pickup.
　
The Silverado, Sierra, Yukon, Tahoe, Yukon XL, Suburban, Trail Blazer and Avalanche as well as many others may use this problem prone unit. It is a Kelsey Hayes 325 ABS module. When the unit fails, the ABS pump is often turned on. If it is allowed to run, it will quickly kill the vehicle battery and may damage the ABS pump.　
Removing the ABS fuse is the best bet, until the vehicle can be repaired. The vehicle can temporarily be driven with the fuse removed, but will not have ABS function available. The large 60 amp fuse is located in the fuse block, under the vehicle’s hood. Most of these vehicles use one of two typical fuse blocks, pictured below.

　
The culprit is an electronic control module, which uses a transistor to switch the pump on and off, rather than a relay. These may be less expensive for GM, but you would never know it by the price. Many of these units are $1000.00 or more, from the GM dealer. Perhaps worse, you get the same design that was supplied with the vehicle.
　
Fortunately, these units can be rebuilt, with better parts than the original and at a fraction of the cost. If you have a problem, AGCO can swap your General Motors, Kelsey Hayes ABS control module with a higher-quality  rebuilt part in about an hour and a half.  Just bring the vehicle in, we will check it and if necessary rebuild your unit.  Sorry, we do not rebuilt units out of the vehicle.  AGCO, it’s the way to go!

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