Oxygen Sensor INSPECTION OF FEEDBACK VOLTAGE (VF) 1. Warm up the engine. 2. Connect SST to the engine service connector. SST 09842-14010 3. Connect the voltmeter to the SST. 4. Warm up the Oxygen sensor with the engine at 2,500 rpm for about 2 minutes. Warm up the Oxygen sensor with the engine at 2,500 rpm for approx. 90 seconds. Short terminals T and E1 of the service connector. And maintain engine speed at 2,500 rpm. Check the number of times the voltmeter needle fluctuates in 10 seconds. Less than 8 times Warm up the Oxygen sensor with the engine at 2,500 rpm for approx. 90 seconds, and maintain engine at 2,500 rpm. Check the number of times the voltmeter needle fluctuates in 10 seconds. 8 times or more Less than 8 times Zero Unshort terminals T and E1 of the service connector. And maintain engine speed at 2,500 rpm. Measure voltage between terminals VF and E1. 0V More than 0V Read and record diagnostic codes Normal code and code 21 Malfunction code(s) (ex. code 21) Repair the relevant diagnostic code. Replace the ECU After replacing the oxygen sensor Normal 8 times or more Zero ① ② ③ ④ CONTINUED ON PAGE FI-74