GM Service Manual Online
For 1990-2009 cars only

The Shift Lock Control Scan Tool Data Definitions contains a brief description of all engine related parameters available on the scan tool. The list is in alphabetical order. A given parameter may appear in any one of the data lists. In some cases, the parameter may appear more than once or in more than one data list in order to group certain related parameters together.

Current Gear: This parameter displays the transmission gear commanded by the control module. The scan tool will display 1 when the control module has commanded first gear regardless of the gear selector position. The scan tool will display up to 6 depending upon which gear is commanded and what transmission is in the vehicle. The scan tool will display 9 if the transmission gear is not known.

Extended Travel Brake Pedal Switch: This parameter displays the state of the brake pedal as determined by the extended travel brake pedal switch. The scan tool will display Applied when the brake pedal is depressed greater than approximately 40 percent of the total travel.

PNP Switch (If Equipped): This parameter indicates the range selection of the automatic transmission as calculated by the control module based on input from the PNP switch. The scan tool will display, In Gear, Park, or Neutral depending on the PNP switch position.

TCC Brake Pedal Switch: This parameter displays the state of the brake pedal as determined by the control module. The control module monitors the pedal switch on the brake pedal for vehicles equipped with an automatic transmission. The control module uses this information to release the torque convertor clutch when the brake pedal is applied. The scan tool will display Applied when the brake pedal is depressed. The scan tool will display Released when the brake pedal is not applied.

TR Sw: This parameter indicates the current state of the gear select switch on the transmission/transaxle as calculated by the control module based on the TR switch. The scan tool status will switch from High to Low as different combinations are met. On the scan tool in Park, the PRNDL would read P and A will be Low, and B and C will be High.