Theory Of Operation
The Transmission Range Switch (TRS) is located on the Transmission at the Selector Shaft. When the driver selects a gear position, the Shifter is moved, which actuates a cable that is connected to the Selector Shaft lever and the TRS. The TRS contains several switches. These switches are OPEN or CLOSED depending on the intended gear position. Normally, at least one TRS Sense circuit switch is OPEN. If the TCM detects that all of the switches are CLOSED, a DTC is set. If the driver leans on the shift lever, forcing it into what is called the Over-Travel position, this will make all of the TRS Sense circuit switches CLOSED and will set this code.
When the TRS sense circuit detects a high voltage condition, it is considered CLOSED. When a TRS sense circuit detects a low voltage condition, it is considered OPEN.