Computerized Engine Controls: Notes

Feedback carburetor (Spectrum) and electronic fuel injected (MPI on Prism and TBI on Metro and Tracker) engine control systems monitor vehicle operating conditions (input signals) and regulate the air/fuel mixture and other engine control operations (output signals) to lower exhaust emissions, while maintaining fuel economy and driveability.

The control systems have a built-in fail-safe mechanism. If a fault occurs while driving, the system will substitute pre-programmed values. Driving performance will be affected, but the vehicle may still be driven.

These systems have a self-diagnostic feature capable of recognizing a system fault and storing a related trouble code in memory for future retrieval and diagnosis.