I don’t know about you, but every second Fiero owner I come across has cruise control problems. Even with my three Fieros, two had a non-functioning and an intermittent cruise respectively. Reason enough to give the Fiero cruise control system the treatment it deserves and hopefully get you cruising again. Even if your cruise is working fine now, it can start working intermittently in the near future, so it may be useful to remember where this article is.
First, the Fiero used two fundamentally different approaches to the cruise control. The 1984-1986 4 cylinder and all V6 Fieros use a separate cruise control module. It is located behind the carpet on the driver side center console. To access it you need to remove the radio console and flip the carpet aside. Fortunately these units don’t go bad very often. I have never seen one break. But you may need to access the module connector for troubleshooting. The second system involves the 1987/88 4 cylinder Fieros with DIS. On these cars, the ECM takes care of the cruise control functions. The advantage is that you can troubleshoot the system with a scantool. The scantool tells you whether or not brake and other switches are on or off. The downside is that you need access to a scantool and if the problem is in the ECM, replacement is expensive. But again, the ECM hardly ever goes bad, the far more frequent reasons for cruise control problems lie in the mechanical parts of the system. Before we get into those, let’s have a very general look at how the cruise control system works.
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