Hello all,

After about 4 hours of Thruway driving at about 75 mph, my service engine soon light popped on. I got the code pulled at autzone and it was the PO125 which is Insufficient Coolant Temperature for closed loop fuel control.

The tech cleared the code, but is this a sign of things to come? The coolant level is fine, should I change the thermostat and coolant temp sensor? Or should I wait to see if it comes back on?

2001 F150 5.4 Triton

Thanks

 

Sounds like your T-Stat is stuck/sticking open. The code means that the egnine is not hot enough to warrant going into closed loop. Most likley just the T-stat. It may be the sending unit, but unlikley. I would hook it to the scanner, look at ECT, and infrared the spot where the ECT is and compare the readings. If the ECT says 140, and the infrared says 140, then you know its the T-stat. You probably dont have a scanner, or want to pay the 50-100 dollars for a shop to do it, so.... Change out the t-stat first, clear codes, and if it comes back on, you know what you have to change next.

Let us know how it turns out.

Hak