Two problems related to brake antilock control unit/module have been reported for the 1999 GMC C1500. The most recently reported issues are listed below.
The abs brake light was illuminated at all times. The consumer heard a humming sound coming from under the vehicle. The abs module was disconnected because the module continued to run although vehicle was turned off. If the module was left connected it could drain the battery and possibly damage other systems. The dealer and manufacturer were informed of the problem. The abs module has not been repaired due to the cost of the repair.
Abs motor continues to run even after the engine has been turned off. Consumer has to pull the fuse to get the abs motor to stop. Dealer has been contacted.