Transmission Diagnosis - With Codes: Operation: General

The gear position switch outputs are monitored by the BECM and the auto gear box control unit. The BECM outputs gear position signals to illuminate the position indicators on each side of the gear, gear selector lever and on the message center in the instrument cluster.

In D, 3, 2, and 1, the auto gear box control unit outputs control signals to the automatic transmission to select the required gear.

In D, all forward gears are available for selection by the auto gear box control unit. In 3, 2 and 1, a corresponding limit is imposed on the highest gear available for selection. When R is selected, reverse gear only engages if the vehicle is stationary or moving at 5 mph (8 km/h) or less.