There are two separate diagnostic systems built into the 1988-89 Reattas and there is some confusion about them. Perhaps this article will explain the differences and make it easier to understand the function of each system.
1. Vehicle Diagnostic System For Owners
This system is intended to be a reference for the car owner to help him understand what the error messages mean that are sometimes displayed on the Reatta's CRT screen by the on-board computers.
This system can be accessed by pressing the Status button on the bottom left of the CRT screen, and then selecting Diagnostics. Once on the diagnostics screen you can select from a number of items on the screen. When you select any of those items you will see an OK button beside them. If you start pressing the OK buttons a simulation will be displayed of what error messages you would see in the event something actually went wrong with your Reatta.
Those messages are for information only. They are not an indication of a current problem with your car.
2. Vehicle Diagnostic System For Technicians
This diagnostic system is designed to help Technicians diagnose problems with your Reatta. If you are seeing error messages on the CRT while driving your car you can use this diagnostic system to aid in troubleshooting problems yourself. Before attempting to use this diagnostic system you should familiarize yourself with how it works. It can be used to troubleshoot the various computer systems on your Reatta. The system can be accessed by anyone but it was not intended to be used by the average Reatta owner.
If you are not familiar with OBD-I engine control electronics you should educate yourself on how the electronics function before accessing the Vehicle Diagnostics System.
Instructions can be found here for accessing and understanding the Vehicle Diagnostics System.
