Control Unit
Electronic Control Unit (ECU) is a microprocessor which controls all functions of TCCS. ECU receives signals from sensors, switches, and ignition and starting systems. ECU has constant source of battery power at BATT terminal. EFI main relay provides battery voltage to terminals +B and +B[I1] of ECU. EFI main relay is activated by turning on ignition switch.
Signals are processed by the ECU for controlling various functions. See OUTPUT SIGNALS in this article.