Fuel Injection
Diagnostic Socket Location:
PURPOSE AND LOCATION
The fuel injection ECU has a self diagnostic and function test system. These are combined with the diagnostic and function test system of the ignition ECU.
The diagnostic system of the fuel injection ECU is capable of detecting 18 faults and storing three different codes. The ECU continuously monitors the following functions during driving:
^ Control unit internal functions
^ Oxygen sensor (lambda sond) control
^ Coolant temperature sensor
^ Intake air temperature sensor
^ Intake manifold pressure sensor
^ Battery voltage
^ Throttle switch
^ Engine speed and position signal (from ignition ECU)
^ Speedometer signal
^ Idle valve operation
To check the fault code memory or a component, you must access the diagnostic socket located in the engine compartment behind the left suspension tower.
Diagnostic Socket Description:
FUNCTION
This diagnostic socket is used for communication with the diagnostic functions in the fuel injection and ignition ECU.
The diagnostic socket consists of a button, an LED and a selector cable. For fault tracing on the fuel injection system, the selector cable is placed in output #2. By pressing the button once, twice or three times (depending on control function required), the fuel injection ECU is accessed.
Control function #1:
This control function will access the fuel injection ECU memory and extract any recorded faults.
Faults stored in the ECU are read via "fault codes" consisting of flashes at the LED.
Control function #2:
This is a function to test selected input components in the fuel injection system. These are the throttle position, RPM, AC compressor and gear selector (A/T only) signal.
Control function #3:
This is used with the engine stopped. Selected output components are automatically tested and activated to check correct operation.
For more information on how to operate all the functions in the diagnostic socket see DIAGNOSIS AND TESTING PROCEDURES.