Toyota Repair: Corolla 1994 1.8L

Question
Hi Ted,

The "check engine" light come on and I suspect it's the oxygen sensor. Using a multimeter to check for voltage and I'm not getting any. Any fuse/relay controlling power to the o2 sensor.

I did the manual diagnostic and came up with code 25 (using check engine light).

Please advise and thank you in advance


Kevin

Answer
Are you using the diagnostic check connector under the to check the voltage, the meter should be connected to terminals OX1 and E1 while the engine rpm is kept at 2000, with the engine warmed up, this assures that the system is in "closed loop" which is when the sensor is sending feedback to the ECM. At that time you should see a fluctuating voltage of about 1 volt positive to negative.