Electronic Spark Advance Computer

The Electronic Spark Advance (ESA) computer, used on some 1985 - 87 models, is programmed to monitor several different component systems. If a malfunction in a monitored circuit is detected often enough to indicate an actual problem, a corresponding ``fault code'' is stored in the computer for display on diagnostic readout tool C-4805. If the malfunction is repaired or ceases to exist, the code will be erased from the computers memory after 30 ignition key on/off cycles.
The diagnostic readout tool can be used to check different modes: the Diagnostic Test Mode, Circuit Actuation Test Mode and Switch Test Mode.