Anyone ever get a P0125?

[jarhed]

P0125 Insufficient Coolant Temperature for Closed Loop Fuel Control

Just flushed and filled the system with new coolant a couple weeks ago. Is it possible that I used too much coolant and not enough water? BTW, I just got a "Low Coolant" light this morning so I'm going to be topping off with RO water. And after replacing the coolant temp sensor, the temp guage on the dash still does the same as before, doesnt bother to work most of the time.

Your thoughts?

[Bjornboy81]

does your heat work? Is the top rad hose get warm? I'm thinking the t-stat is stuck open which won't allow the engine to warm up enough to go into closed loop mode.

[rixGAphx]

2001 V-6, 5 yeras old, so about 75k miles.
Your facotry DexCool wa *supposed* to last 150k miles; why did you drain/flush/refill?

A. When you 'top-off', ONLY refill to the designated line on the reservoir (which is about 1" below the filler neck).

B. No, it's not possible that the 'low temperature' condition is caused by incorrect water-antifreeze proportions.
1. Look at an antifreeze bottle: The 'recommended proportions' for W-AF vary from about 60-40 to 30-70. So you can be WAY 'off' and still be within range.
2. AF actually conducts heat LESS WELL than plain water!!! 'Tis TRUE!!
But, the anti-BOILING properties of the AF make it better for the system overall during hot weather.
So, having HIGH proportion of AF would actually make the enigne run HOTTER than having high proportion of water.

C. Water for cooling systems.
1. The best water to use is 'Distilled' water, which is pure H2O.
2. Second best is the bottled 'purified' water, like one uses for steam irons.
3. Most 'RO' water only takes out the chlorine and other foul-tasting chemicals, but leaves in the calcium and potassium because they make the water taste 'good', just like bottled 'drinking' water. Calcium and potassium are the two minerals that foul-up hot water systems.
As far as the cooling system is concerned, RO water isn't much better than tap water (though it's certainly better than some mineral-rich private well water).
4. ANY water-based liquid can be used in an emegency (dirty puddle water, thermos of coffee, etc.), though soda, beer, and champagne tend to cause a lot of 'air' bubbles (actually CO2), and vodka tends to boil-out the alcohol :eek:.

D. Coolant Temp Sender:
1. Make sure your battery cables are clean and tight and shiny brite.
See one of my eleventy billion other posts for the procedure.
2. AND, make sure the Body Ground Wire (smaller black wire from NEG batt terminal to the body, with a screw located driver side near the hood line, kinad alongside the strut tower).
This is prone to rusting, which prevents proper flow of electrical power from the engine to the body to the gage (along the ground 'return' path).
3. SOME senders in the engine block require that the threads be clean, dry metal-to-metal. If you didn't clean the block threads orf rust, or used Teflon tape or other gunk for a good 'seal', then you effectively put electrical insulation between two metals designed to CONDUCT electricity.
I've encountered this before on Oil Pressure senders, don't know if it applies to the 01's temp sender or not.

E. T'stat
1. Like Bjornboy said, if the heater does NOT work and/or the rad hose is still cold, then the t'stat is *prolly* stuck 'open'.
2. If the heater works and/or the rad hose is warm/hot, then the problem is NOT with the coolant temperature, but rather with the sender OR IT'S CIRCUIT.

Hope this helps.
-Rick

[jarhed]

Originally posted by Bjornboy81
does your heat work? Is the top rad hose get warm? I'm thinking the t-stat is stuck open which won't allow the engine to warm up enough to go into closed loop mode.

Heat works well, havent check the radiator hose. I was thinking about a bubble in the system, which is easy enough to get. I'll check it out.

[jarhed]

Originally posted by rixGAphx
2001 V-6, 5 yeras old, so about 75k miles.
Your facotry DexCool wa *supposed* to last 150k miles; why did you drain/flush/refill?

Because it was mud. My guess is that whoever had it before me (bought it in '02 - it was a fleet vehicle) put regular coolant in it.



A. When you 'top-off', ONLY refill to the designated line on the reservoir (which is about 1" below the filler neck).

Right. I'm aware of that.


C. Water for cooling systems.
1. The best water to use is 'Distilled' water, which is pure H2O.
2. Second best is the bottled 'purified' water, like one uses for steam irons.
3. Most 'RO' water only takes out the chlorine and other foul-tasting chemicals, but leaves in the calcium and potassium because they make the water taste 'good', just like bottled 'drinking' water. Calcium and potassium are the two minerals that foul-up hot water systems.
As far as the cooling system is concerned, RO water isn't much better than tap water (though it's certainly better than some mineral-rich private well water).
4. ANY water-based liquid can be used in an emegency (dirty puddle water, thermos of coffee, etc.), though soda, beer, and champagne tend to cause a lot of 'air' bubbles (actually CO2), and vodka tends to boil-out the alcohol :eek:.

I should have posted that the water I use is RO/DI. I have a Reverse Osmosis/Deionized water filter for use in my 180gal in-wall saltwater reef at home. This water is so pure that it's not even safe to drink (will dissolve and flush out needed salts and minerals from your body in large quantities). It does have an RO only outlet connected to my fridge though. Actually better than distilled because even distilled will grow algae when exposed to light.... like the bottles are in the grocery store.


E. T'stat
1. Like Bjornboy said, if the heater does NOT work and/or the rad hose is still cold, then the t'stat is *prolly* stuck 'open'.
2. If the heater works and/or the rad hose is warm/hot, then the problem is NOT with the coolant temperature, but rather with the sender OR IT'S CIRCUIT.

Hope this helps.
-Rick

Actually it does. Thing is, the error states that there is INSUFFICIENT coolant temperature, which leads me to believe that it's just flat out too cold for whatever reason, or the sensor is not picking up properly (perhaps ANOTHER faulty sensor from Autozone?). Definitely makes sense. They gave me warranty papers on it when I picked it up (course I threw it away - part was only $15 or so). I guess that should have tipped me off that it was a part that goes bad and is frequently bad right out of the box.

:mad:

[rixGAphx]

The coolant in a GA V-6 must ALWAYS be 'burbed' thru the bleder valve (behind the water pump) whenever the system is topped-off.

But, air in the system, even a LOT of air, prevents coolant flow thru the radiator (and heater core), so the engine gets HOT, not stays cold.
* * *

Go ahead and top-off, and burp it.

But forget about the coolant system itself causing the P0125.
Since you have heat thru the heater, your coolant and engine ARE reaching the proper temperature.

The sender sends the data to the PCM (Powertrain Control Module, the engine/tranny 'puter), which uses the data to:
1. Cause the gage to read; AND,
2. Cause the PCM to determine the right air-fuel mixture.

Since the engine and coolant ARE warm, AND your gage mis-reads, AND the PCM is telling you it's not getting a signal of 'engine is warm', then the problem is in the sender and its electrical circuit.
Or with the PCM itself, but I doubt it.

Check-out thos ground cables, and verify that the new sender was installed in accordance with insturctions. Then, closely examin the wires from the sender into the wiring loom; even a tiny nick in the insulation could cause this problem.

Meantime, as long as the PCM is sending this code, it's staying in 'open-loop' mode, running VERY rich to prevent engine damage that comes from a lean mixture.
So your gas milage is really gonna suck, and the extra richness may be destroying your O2 sensors and the cat.

Good luck.
-Rick

[rixGAphx]

Originally posted by jarhed

Thing is, the error states that there is INSUFFICIENT coolant temperature, which leads me to believe that it's just flat out too cold for whatever reason, or the sensor is not picking up properly
It only needs to register 140*F, then the 'puter takes it from there.
Even if there were a protective plastic cap on the end of the new sender (which shoulda been noticable), then the sender WOULD STILL 'feel' at least 140* if the coolant were at operating temp (180-195*F).

(perhaps ANOTHER faulty sensor from Autozone?. Definitely makes sense.
Bite your tongue!!! :D :D

They gave me warranty papers on it when I picked it up (course I threw it away - part was only $15 or so). I guess that should have tipped me off that it was a part that goes bad and is frequently bad right out of the box.
Mebbe.

But your problem is VERY ODD.
The coincidence of a New Faulty Sender having the SAME FAULT as an old sender is EXTREMELY unlikely IMO.

Mebbe the socket into which the sender wires plug has some crud in it, or wire nicks, etc.
How many wires come from the sender?

-Rick

PS: Today's my birthday, gotta go to lunch, catch you later. :bye:

[jarhed]

Happy Birthday Rick!!!!

Actually, I never got that code before I replaced the sender and flushed/filled the system. And there was no plastic cap on the end of the new part either. The only problem I had before was never getting the guage to show the temp and of course, never actually seeing the electric fans working.

Yep, I definitely burped the system through the bleed valve when I flush/filled. Perhaps I didnt do it enough. I did it until the fluid started turning orange. Never got much air through it.