GM Service Manual Online
For 1990-2009 cars only

The Shiftlock Control Scan Tool Data Definitions contains a brief description of all shiftlock 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: On vehicles equipped with an automatic transmission the scan tool displays 0-4. The scan tool displays which gear the transmission is in. An illegal transmission position displays 9.

PNP: On vehicles equipped with an automatic transmission the scan tool displays Park/Neutral or In Gear. When the transmission is in park or neutral the scan tool displays Park/Neutral. When you place the gear selector into reverse or any forward gear position, the scan tool displays In Gear.

TCC Brake Pedal Switch: On vehicles equipped with an automatic transmission the scan tool displays Applied or Released. When the engine is running this parameter indicates the state of the TCC brake switch circuit input. The scan tool displays Applied when you apply the vehicle brakes. The torque converter clutch disengages. The scan tool displays Released when you release the vehicle brakes. This allows the torque converter clutch to engage.

TR Sw.: On vehicles equipped with an automatic transmission the scan tool displays Park, Reverse, Neutral, Drive 4, Drive 3, Drive 2, or Drive 1. The Transmission Range (TR) switch indicates the driver selected gear position.