Code P102, Shorted Brake Booster Vacuum (BBV) Sensor: Notes
WARNING: This page is about a different car, the 1995 Cadillac Eldorado. However, it is still accessible from the selected car via links, so may be relevant.
Brake booster vacuum sensor changes resistance based on vacuum inside brake booster. This test checks for a vacuum reading which can be caused by a shorted sensor or a short on circuit No. 1726 or and open on circuit No. 808. Every time TCC brake switch cycles from closed to open with engine not at idle, this test checks for a shorted vacuum signal. If shorted vacuum signal is detected for 5 consecutive cycle of TCC brake switch, Code P102 will set. Any cycle of TCC brake switch where a shorted vacuum signal is not detected will reset counter to zero.