Fuel Injected System

The EFI system has a self diagnosis function which is controlled by the ECM and receives signals from various sensor inputs. If any sensor related problems occurs, the trouble area can be located. The cause of many faulty engine conditions can be found in basic vehicle components. Check these components prior to checking the EFI system for malfunctions.
If a malfunction occurs in the input signal caused by a malfunction in one of the EFI system components, the ``Check Engine'' lamp will light on the instrument panel and flash to inform the presence of trouble and its location.
When the ignition switch is turned on, the ``Check Engine'' lamp lights momentarily so the condition of the lamp can be checked. If in good condition, the lamp will go out. If a malfunction exists, the ``Check Engine'' lamp will remain ``On'' until the malfunction is corrected. The malfunction will be stored in the ECM memory as a diagnostic code, even if in the event the problem, such as a loose ground, corrects itself. Therefore, after a malfunction, clear the diagnostic code from memory, by disconnecting the battery ground cable for approximately 20 seconds to clear the code from the ECM memory.
When the diagnostic switch, located under the instrument panel, is turned ``On'' with the engine off and the ignition switch turned on, the check engine lamp flashes to indicate the diagnostic code in the ECM memory. When the CPU is defective, the ``Check Engine'' lamp remains ``On'' without flashing.