Code 31, Open 36VLR To Deployment Loop: Description
WARNING: This page is about a different car, the 1992 Oldsmobile Custom Cruiser, 1992 Chevrolet Caprice, and 1992 Buick Roadmaster. However, it is still accessible from the selected car via links, so may be relevant.
Voltage at SENSE LOW input (terminal A6) is within a specific range of 36-Volt Loop Reserve (36VLR) output when 36VLR output of Diagnostic Energy Reserve Module (DERM) is functional. Should circuit open between 36VLR output and arming sensor, IGNITION 1 voltage will supply deployment loop. Voltage at SENSE LOW input (terminal A6) will decrease due to lower 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 arming sensor.