PGM-FI Control System: Notes

The PGM-FI is part of the ECU which is located behind the passenger seat in the passenger compartment. On the engine cover wall. The ECU has a built in Fail-Safe Function. When an abnormality occurs in a signal from a sensor, the ECU ignores that signal and assumes a pre-programmed value that allows the engine to continue to run. ECU is programmed with a Back-up Function.

When an abnormality occurs in the ECU itself, the injectors are controlled by a back-up circuit independent of the system in order to permit minimal diving. The ECU also has a built in Self-diagnosis Function (Check Engine light). When an abnormality occurs in a signal from a sensor, the ECU lights the Check Engine light and stores the failure code in erasable memory. When the ignition is initially turned on, the ECU supplies ground for the Check Engine light for two seconds (bulb check). If check engine light never comes on after ignition is turned on, go to CHECK ENGINE LIGHT NEVER COMES ON (EVEN FOR 2 SECONDS) AFTER IGNITION IS TURNED ON  . If check engine light stays on after 2 seconds, go to CHECK ENGINE LIGHT STAYS ON AFTER 2 SECONDS  .