Diagnostic Aids
WARNING: This page is about a different car, the 1992 Geo Prizm. However, it is still accessible from the selected car via links, so may be relevant.
After engine is started, engine coolant temperature should rise to approximately 203°F (95°C) and stabilize when thermostat opens. Code 22 will set if Brown or White wire is open. If code is intermittent, see TESTS W/O CODES article in this section.