TonyAn

This code indicates low coolant temp for closed loop fuel control. Well I have changed the thermostat, engine temp sensor and new coolant. After driving approx. 5 miles the light came on again. Any feedback is appreciated.

VVTiBob

Sounds like a bad O2 sensor but from reading the DTC description it could be other areas but not as likely. I am attaching the diagnostic for a 0125 error as one PDF document and the DTC Chart for most errors.

TonyAn

Thanks for ur feedback. Now that you've mentioned the O2 sensor, this P0125 code came on after I had changed all 4 O2 sensors by my mechanic. I'm gonna take it back to him with the charts.

emg2919

Any luck on getting this resolved? I have the same issue. P0135, bank 1 sensor 1, replaced by toyota dealership, now P0125 error. I think they botched the install or it's a faulty 02 sensor. I bought the OEM denso from rockauto...not from sewell though.. Thoughts?

TonyAn

Yes, one wire from the oxygen sensor broke when the mechanic installed it. It's in a very tight place, I believe it was the one under the driver side sensor wires. I would suggest that you double check that the wiring is good and no loose connection. Good luck.

emg2919

Great, will do. Thanks.

tecc5ryan

hey i know this thread is old but do you have page 0579 and 0560 i have a gs 430

DshngDaryl

This is the SC 430 forum. Though the cars have the same engine, you may have better luck in the GS Forum.

Still, the info on those pages is probably relevant.

What issue are you having?

WtSpyder

I am getting DCT P0120 also. Is there a ways to tell which sensor needs to be replaced? I don’t want to replace all four if only one is bad.

DshngDaryl

Are you getting a P0120? or a P0125? A P0120 is a throttle position sensor.

Let us know which code and we can help you.

If it is a P0120, I would recommend you start a new thread

WtSpyder

P0125 good catch. I fat fingered it.

DshngDaryl

From the past posts of people with a P0125, it looks like it is usually Bank 1, sensor 1.

That means it is the sensor on the driver's side (if you are in the US) and the one before the catalytic Convertor

BTW: This is probably the easiest O2 sensor to replace on the car. Harness is close by instead of being in the passenger compartment

WtSpyder

Thanks I’ll pick one up.

DshngDaryl

Best if you go Denso...

Amazon actually has an amazing deal on it. $50 less than other places. Almost makes me wonder if it is counterfeit