Obdii Code P0125

[totalsolution]

Have the code on the wife's car. I have a diagonostic code reader. I have cleaned the MAF sensor, replaced the thermostat (cheapest option and they get sluggish) and checked out the temp sensor, that seems fine. New coolant. Reconnected the Battery and was ok. Then it came back....

Anyone cured this little problem? Will investigate more.

Temp sensor readings for you

Cool 2.5K ohms

Boiling hot <300 ohms

Note there are three wires going into sensor but only two are used?

There is a slight hiss noise my daughter has mentioned will look for a gas leak..

Last mot garage said o2 sensor was required, wunder if it was now and thats is the problem...

1999 1.0l

70,000 miles

Thanks for your help.

Paul

[dagbladet]

Googled and taken from another board;

P0125 OBD-II Trouble Code

Technical DescriptionInsufficient Coolant Temperature For Closed Loop Fuel Control

What does that mean?This means that the engine coolant temperature (ECT) sensor indicates that the engine has not reached the required temperature level to enter closed-loop operation within a specified amount of time after starting the engine.

SymptomsYou will likely not notice any drivability problems.

CausesA code P0125 may mean that one or more of the following has happened:

Insufficient warm up time

Low engine coolant level

Leaking or stuck open thermostat

Faulty coolant temperature sensor

Possible SolutionsThe simplest thing to do is to reset the code and see if it comes back.

If the code comes back, the problem is likely going to be the result of the above causes (faulty thermostat, faulty coolant sensor, or a low coolant level).

http://www.obd-codes.com/trouble_codes/gen...uel-control.php

[totalsolution]

Hi Thanks for your reply. I think I'm on the right track here.

The Haines manual shows the coolant sensor with two wires (electrical dia) but there are three on the sensor and connector plug. The meter only shows two of the three terminals have any resistance and a new one is £50 when mine seems ok.

Anyone test theirs and let me know?

Paul

[Yaris SR Kid]

I had this code 6 months ago, lasted for a months then went away, i think i picked up some water through induction kit that got into coolant!

[totalsolution]

New topic posted with my fix.

The hissing noise I think was due to the "o-ring" sealing the air filter box to the carb. Removed the three securing bolts on the air filter assy. and found an O-ring there. Removed and cleaned and a smear of oil it was refitted and runs fine or even better.

Of note the car will not run with the filter assy. off the carb. I note that this is due to the clever computer (ECU) controls running the injection system. Lifting off the filter unit with MAF attached kills the engine due to NO air passing MAF sensor and cooling it (it works by being heated electrically and then cooled by the cold air drawn over it) as it is sucked into the carb. The ECU thinks there is no air and shuts down the fuel supply.

So , with air bypassing the MAF sensor less fuel is sent to the engine, a weaker mix ensues, less power, more welly to get the car going more fuel used....

Paul