One problem related to brake sensor has been reported for the 1999 Toyota Camry. The most recently reported issues are listed below.
While driving traction control at 65000 miles failed. The light illuminated on the dashboard. Took vehicle to the mechanic, and he reset it. Then, it happened again, light came on while consumer was driving. Consumer bought the part; had it put on. Within a month the air bag light illuminated on the dash. Took the vehicle back to the mechanic they found that the air bag sensor module was defective. Air bag on the passenger side was completely inoperable.