GM Service Manual Online
For 1990-2009 cars only

Body Control Module (BCM)

Battery Voltage Signal: Display indicates battery voltage. Measured in volts.

BTSI Solenoid: Displays the status of the control circuit for the shift lock control solenoid. ON indicates the control circuit is grounded. OFF indicates that the control circuit is not grounded.

Engine Control Module (ECM) / Powertrain Control Module (PCM)

BPP Circuit Signal: Display Applied or Released status of the brake pedal position signal.

Ignition 1 Signal: Display indicates ON when the ignition 1 input circuit of the module receives a battery signal from the ignition switch.

Stoplamp Pedal Switch: Display Applied or Released status of the stoplamp pedal switch.

TCC Brake Switch: Displays ON or OFF status of the TCC Brake switch.

TR Sw. : Displays Park, Reverse, Neutral, Drive 5, Drive 4, Drive 3, Drive 2 or Drive 1.