Fuel Pump Relay: Description and Operation

The control system controls the fuel amount, using the ECU, by detecting the engine and vehicle running conditions, based on signals inputted from various sensors.

Fuel Pump Control
This system actuates the fuel pump by turning on the fuel pump relay when the starter switch is turned on or when the ECU detects engine rotation.

Electronic Ignition Timing Advance System
This system, controlled by the ECU, selects an optimum ignition timing by comparing engine conditions to the data memorized in the ECU.

Fail-Safe Functions
On 1989 models, if any abnormal signals are inputted into the ECU that may cause the engine to malfunction by using this abnormal signal, the fail-safe function system determines whether the engine may be allowed to continue to operate or if the engine should be stopped immediately.

On 1990-92 models, if any abnormal signals are inputted into the ECU that operation can no longer be continued based on the inputted data, running is made possible by using data stored in the ECU in advance.

Back-Up System
In the event that the ECU should fail, this system makes it possible for the vehicle to continue to run by using back-up data.