I know this question has been asked before but I can't find a thread. Just picked up and '02 150 XL and it's throwing codes for bad coolant (which is correct, it looks nasty), t-stat and/ or coolant temp sensor.

Can anyone tell me where it is? What tools I'll need and what to watch out for?

Thanks!

 

Which code(s) are you getting?

 

Autozone pulled:

1) Closed loop fuel ctrl
2) Coolant temp is always low
3) Ck coolant level
4) T-stat defective
5) ECT sensor defective

Even though I've owned four Ford trucks, I'm not sure how to do the "key dance," on them to pull codes. If the procedure is the same as a MOPAR, I can do it to see if I get anything different than Autozone.

Thanks!

 

Hate to bust your chops, but we need the P-numbers of the codes, not what Autozone interprets them as.

No key dance on a Ford, you need a code reader. You can buy a cheap one that works for 35 bucks.

 

Temp sensor should be behind the alternator on that aluminum bridge going from the t-stat to the other side of the engine. You gotta use pipe thread sealer too on the threads when replacing. Also note, when removing the lower and might as well do the upper, change the clamps to screw type, easier to work with believe me. T-stat sounds like it's definetely gone for a poop.

 

Hi,

Always get the actual Pxxxx codes from Autozone if you can. The folks around here know their stuff and can often diagnose the problem accurately the first time with the codes vs. Autozone's interpretation. I second the idea of a cheap code reader. I have an Actron that cost me around $40 and it's invaluable!

Regarding your temp/coolant troubles, I suggest trying the easier fixes first. Replace the thermostat and make sure the coolant level is correct. I've solved problems similar to yours on two F-150s and one Explorer doing only the t-stat and topping off the coolant. If that fixes the problem, you can then change and flush the coolant, which sounds like it needs to be done anyway. :-)

Something to watch out for... if your coolant level is already full, drain some off before opening the t-stat housing. Otherwise, coolant can run into the spark plug well for cyl 5 (driver's side front) and make a mess!

 

Thanks for the tip on the Actron unit. I'm going to get one. Lucked out in this case. the Autozone info was good enough. I flushed coolant and installed a new t-stat. disconnected battery to reset PCM and check engine light is gone.

Thanks for the input guys.

 

One other question. Do I even have a Coolant Temp sensor on my truck (2002)? A friend said they did away with those in 2000 and they use a Cylinder Head temp sensor now.

 

I have read the same thing in the forums here.

I just checked the schematic in the back of the Chilton's Manual for my truck. It shows both a Cylinder Head Temp. sensor and an Engine Coolant Temp. sensor, and it identifies a different color wire for each. My truck is 2000 4.6. Did this change in later models?