System Description

GENERAL INFORMATION
The Multiport Fuel Injection System consists of sensors which detect the engine conditions, the Powertrain Control Module (PCM) which controls the system based on signals from these sensors, and actuators which operate under the control of the PCM.

The PCM carries out activities such as fuel injection control, idle air control and ignition timing control.

In addition, the PCM is equipped with several diagnostic test modes which simplify troubleshooting when a problem develops.

DIAGNOSTIC TEST MODE
- When an abnormality is detected in one of the sensors or actuators related to emission control, the CHECK ENGINE/MALFUNCTION INDICATOR LAMP illuminates as a warning to the driver.
- When an abnormality is detected in one of the sensors or actuators, a diagnostic trouble code corresponding to the abnormality is output.
- The RAM data inside the PCM that is related to the sensors and actuators can be read by means of the scan tool.
- In addition, the actuators can be controlled under certain circumstances.

OTHER CONTROL FUNCTIONS
1. Fuel Pump Control
- Turns the fuel pump relay ON so that current is supplied to the fuel pump while the engine is cranking or running.
2. A/C Compressor Clutch Relay Control
- Turns the A/C compressor clutch ON and OFF.
3. Fan Relay Control
- The radiator fan and condenser fan speeds are controlled in response to the engine coolant temperature and vehicle speed.
4. Generator Charging Control
- Controls the generator field current in order to control the generated current.
5. Engine Speedometer or Tachometer Control
- Sends a pulse signal which corresponds to the engine speed to the speedometer unit.
6. Evaporative Emission Purge Solenoid Control
7. Electric EGR Transducer Solenoid Control.
8. Pulsed Secondary Air Injection Solenoid Control.