Code 31, Open 36VLR To Deployment Loop: Description
WARNING: This page does not describe the selected car, but rather 10 other vehicles, including the 1991 Oldsmobile Toronado, 1991 Cadillac Seville, 1991 Cadillac Eldorado, 1991 Buick Riviera, and 1991 Buick Reatta. However, it is still accessible from the selected car via links, so may be relevant.
Voltage at SENSE LOW input is 41-61 percent of 36VLR output when 36VLR output of DERM is functional. Should circuit open between 36VLR output and dual sensor, IGNITION 1 voltage will supply deployment loop. Voltage at SENSE LOW input will decrease due to decrease in supply voltage, and Code 31 will set after 700 milliseconds (if Code 42 is not set). Code 31 indicates an open in wiring between 36VLR output of DERM and dual sensor, an open diode in dual sensor or a problem with SENSE HIGH or SENSE LOW circuits.