Code P102, Shorted Brake Booster Vacuum (BBV) Sensor: Action

PCM turns on SERVICE VEHICLE SOON message.

NOTE: Test numbers refer to numbers on diagnostic chart.

PCM data PD84 will read 82-84 kPa with sensor shorted. If reading is not as specified, fault is not present.
If PCM data PD84 reads -11 to -8 kPa with sensor unplugged, check circuit No. 476 for open or for a shorted sensor.
Checks circuit No. 1726 for short to voltage.

Fig 1: Code P102 Schematic, Shorted Brake Booster Vacuum (BBV) Sensor

Courtesy of GENERAL MOTORS CORP.

Fig 2: Code P102 Diagnostic Flow Chart, Shorted BBV Sensor

Courtesy of GENERAL MOTORS CORP.