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 "+B1" of ECU. EFI main relay is activated by turning on ignition switch.
Signals are processed by the ECU for controlling the following functions:
- Air Injection (Emission Systems)
- Air Suction Control (Emission Systems)
- Electronic Fuel Injection (Fuel Delivery)
- Electronic Spark Advance (Ignition System)
- EGR Control (Emission Systems)
- Electronic Controlled Transmission
- Idle Speed Control (Fuel System)
- Idle-Up System (Fuel System)
- Intake Air Control System (Air Induction System)
- O2 Sensor Heater (Emission Systems)
- Self-Diagnostic System (Self-Diagnostic System)
- Turbocharging System (Air Induction System)
The ECU contains self-diagnostic and fail-safe capabilities. The ECU is equipped with a self-diagnostic system which detects system failures or abnormalities. When malfunction occurs, the "CHECK ENGINE" light on instrument panel is activated.