The Reatta Onboard Diagnostics Instructions for 1990 & 1991 models consists of six pages of instructions. The pages should be viewed in sequence.
These instructions will explain how to access all the features of the 1990 & 1991Reatta On-board Diagnostic System. They will explain how you can check current data being sent by the sensors. They will also show you how to override the computer to control certain devices such as the EGR valve for testing purposes.