Check Engine Light - P0125

[Burke25]

I recently had my check engine light come on in a 2001 ZX2, and the code I am getting is P0125 - Closed Loop Fuel Ctrl Insufficient Coolant Temp. I thought maybe the temp sensor that goes in the engine block was bad and replaced it, but no such luck.

Also, the temp gauge on the dash constantly reads that the engine temp is "below the cool line", but heat is coming out of the vents.

Any insight as to the problem would be appreciated!

[toddman67]

Someone from another post had the same symtoms, same car,same code. It ended up being a bad thermostat and low coolant level in the O-flow tank.

[ricebike]

stuck open thermostat... if i recalled correctly from that other thread...

[Burke25]

I will replace the thermostat this weekend and hopefully the problem will be solved. Sorry about not seeing the previous post, I'm new to this forum!

[ricebike]

hmm, seems like it's just one of the possibilities:

http://www.automotiveforums.com/vbulletin/t352809.html

did you reset the car's pc after you changed out the sensor the 1st time?

maybe it can also be the wiring to the sensor?!?

[Burke25]

Originally Posted by ricebike

hmm, seems like it's just one of the possibilities:

http://www.automotiveforums.com/vbulletin/t352809.html

did you reset the car's pc after you changed out the sensor the 1st time?

maybe it can also be the wiring to the sensor?!?

Last weekend, I changed out the temperature switch (the part that goes directly into the engine block) and that didn't fix the problem. I reset the PC and the light came back on two days later, showing the same code PO0125.

I am going to give replacing the thermostat a shot this weekend and hopefully that will fix the problem. I guess my next step after that is the wiring. I will keep you updated. Luckily the cost of these parts is not too high...

[Burke25]

Hope I'm not jinxing myself, but replacing the Thermostat seemed to do the trick!! Thanks to everyone who helped out!

[ricebike]

thanks for the reply, burke!

should help someone else in the future when they'll be searching for this similar problem