- Electronic Fuel Injection Symptoms

Fig. 6a Electronic fuel injection system symptom diagnostic chart (Part 1 of 2):

Fig. 6b Electronic fuel injection system symptom diagnostic chart (Part 2 of 2):

Refer to Fig. 6, for conditions related to the EFI system but are not subject to the self diagnostic function.
If a problem still exists, and the component checks prove to be satisfactory after the diagnostic checks, recheck the ECM for proper connections. If trouble code cannot be eliminated, replace ECM with a known good one and perform diagnostic check. If same trouble occurs, and it is one of the self diagnostic functions, stop engine and turn on both the ignition switch and the diagnostic switch and check that the check engine lamp indicates code 12 (Normal). If trouble code is eliminated, ECM is defective and should be replaced.
If the problem area has occurred in the oxygen sensor area, operate vehicle in 3rd, 4th or 5th gear position and when engine speed has risen to 2,000 RPM, depress the accelerator pedal fully for more than 2 seconds. Stop engine, then with ignition switch on, operate diagnostic switch. To minimize the chance of personal injury or vehicle damage, operate vehicle in a safe area when performing test.
When removing or installing connectors, ensure ignition switch is off or battery ground cable is disconnected. Do not inspect ECM by using a circuit tester as tester probes may short between terminals and cause damage to components. Do not expose ECM to excessive shock.