Error code p0125 keeps coming up on LX470. Have replaced thermostat and temp sensor, changed coolant. Check engine light keeps coming on with same p0125 code. Temp gauge is reading normal and car runs normally. Temp when monitoring OBD port while driving is reading 90-91C. Any suggestions as to what to do next? Any help much appreciated. Thanks.https://www.clublexus.com/forums/ima...1387914497.gif

 

Hi,this sounds strange,but this code is phantom,it will have another one following it for an air fuel ratio sensor.Replace only this AF sensor and the P0125 will be gone too.Problem is you will have to wait for the specific code of the AF sensor (like B1S1,B2S1.....) comes up.Hope this helps.

 

It's been a couple weeks and so far the only code that comes up is the p0125. Have reset code with the OBD reader multiple times and have tried resetting by disconnecting the battery for an hour. Only code that returns is the P0125 with nothing elso that the OBD reader registers. I will try replacing the A\F sensors next. This is getting frustrating. Thank you much for the help.

 

Hi Friends, I have LX470 - 2000, and keep getting this Code of P0125 + P0150 + P0153,
I tried to search the Forum for replies on similar problem but could not locate anything,
Can you please guide on what shall I do.

I'm talking to you from Dubai-UAE and the Mechanics over here always use trial & error way to fix the problem and I don't want to do that.

Kindly Help,
Thanks in Advance

My LX is imported from USA

 

P0125 is insufficient coolant temp for closed loop fuel trim
P0153 and P0150 are o2 sensor, Bank 2 sensor 1 errors

The 0125 will probably go away when you address the o2 sensor.

Bank 2 is passenger side, sensor 1 is the o2 sensor mounted in the exhaust manifold (engine room).

Dont wait on the o2 sensors as this can cause catastrophic failure in the catalytic converter.

 

P0125 has nothing to do with the thermostat or cooling system. basically, the computer wants to see the coolant temp rise at a similar rate to oxygen sensor temp. when an oxygen sensor temp (known by sensor resistance) does not rise as expected, it throws P0125. typically this code is seen with 02 senors codes. Look for an oxygen sensor (sensor 1) that reads 0.1 volts or less permanently or is very slow to start reading on cold start. I've seen completely dead sensors throw p0125 alone, and i'm not sure why no other codes come with it.

And sorry about the wording of the code description. It has fooled the best of us at one time or another.