Engine Running Test

Code interpretation using analog voltmeter:

Engine running test output codes:

1. Start and operate engine at approximately 1500 RPM for 2 minutes to allow EGO sensor to reach normal operating temperature.
2. Turn ignition switch to OFF position and insert jumper wire as shown in Fig. 25, and wait 10 seconds.
3. Start engine, if system checks out satisfactorily for hard faults, service codes should be as follows:
a. Voltmeter needle should sweep two, three or four times without a pause, depending on the number of cylinders in the engine, Fig. 35.
b. Next, the voltmeter needle sweeps once after a six to twenty second pause. This is the dynamic response code.
c. After a four to fifteen second pause (to momentarily place the throttle in a wide open position) the voltmeter needle will fluctuate from zero to three volts for the fast codes.
d. Finally the voltmeter needle will sweep twice (with a two second pause in between the sweeps) representing another code 11. After four seconds this code will be repeated.