6.
Probe(+) :O2 sensor harness connector NO2.
Probe(-) : Chassis ground.
This is the inspection procedure to determine whether it is present DTC or memoried one by monitoring the current signal or by using the function of oscilloscope with Hi-scan pro.
Connect scan tool to DLC.
IG KEY : ON
Warm up engine to normal operating temperature
Check for HO2S control at idle.
Service standard
For front HO2S
When decelerating suddenly from 4000rpm : 200mV or less
When engine is suddenly accelerated : 600~1000mV
1500rpm : The fluctuation between 400mV or less and 600~1000mV
This inspection procedure is recommended when service data with scan tool is not enough.
Warm up engine to normal operating temperature
Probe(+) :O2 sensor harness connector NO2.
Probe(-) : Chassis ground.
This figures show the waveform measured at terminal 2 of HO2S at idle.
The average voltage of HO2S should be 0.5 V.
The HO2S voltage at point ① is lean air/fuel duration and its usual voltage is below 0.2V.
The HO2S voltage at point ② is rich air/fuel duration and its usual voltage is over 0.7V.
In case the duration ① is longer than the duration ②
Possible cause : Clloged injector,low fuel pressure faulty MAPS, air leakage in intake system.
In case the duration ② is longer than the duration ①
Possible cause : Injector leakage,high fuel pressure,faulty MAP sensor faulty ECTS.
In case DTC is displayed but front and rear HO2S signal is normal.
The problem may be intermittent so shake harness slightly and check there is any sudden data change.
If the data for HO2S works normally, check the connecting condition and terminal condition for MAP,TPS,HO2S or ECM.
And also this may be previous DTC which was not erased ,so erase DTC and check it reoccure.
Go to "Terminal and Connector inspection"
This figures show the waveform measured at terminal 2 of HO2S at idle.
The average voltage of HO2S should be 0.5 V.
The HO2S voltage at point ① is lean air/fuel duration and its usual voltage is below 0.2V.
The HO2S voltage at point ② is rich air/fuel duration and its usual voltage is over 0.7V.
In case the duration ① is longer than the duration ②
Possible cause : Clogged injector,low fuel pressure faulty MAPS, air leakage in intake system.
In case the duration ② is longer than the duration ①
Possible cause : Injector leakage,high fuel pressure,faulty MAP sensor faulty ECTS.
