Test Procedures
Perform tests as described under SYSTEM DIAGNOSTIC CHART. If results are incorrect, perform designated test. Do not press both the set switch and Resume/Accel position of cruise switch at same time with engine running. If quick checker displays a short light, release switches immediately.
When performing the following tests, refer to SCHEMATIC DIAGRAMS/ELECTRICAL AND ELECTRONIC DIAGRAMS/WIRING CIRCUITS. for wiring diagram and SCHEMATIC DIAGRAMS/ELECTRICAL AND ELECTRONIC DIAGRAMS/ELECTRICAL CONNECTORS for control module pin locations.
For additional system diagnosis on 1989-90 Electra, Park Avenue and 1989-91 LeSabre, refer to TROUBLESHOOTING.