Code 15 - Low coolant temp?

phoonTy

Truckless. For now.
So my truck has been running fine lately. better than usual i think, as it has been idleing much smoother. Anyway, I'm out driving it today and get a check engine light. Pulled over to check it, and it's a code 15.

There was a little discussion on this before, but i was unable to dig up the topic, and can't find it in my bookmarks. I know my truck runs like crap when it comes up, because it's happened before.

It pops up about once a year, I reset the computer to verify it's a legit code, and it doesn't come up again for a year. But that wasn't the case today. It came up 3 times in my driving around town, and then, just as I came home, it didn't come back on.

I believe in the old topic, Mike Lee was explaining to me that it has more to do with with intercooler system than the engine coolant system. So my next question is, what should I look at in terms of causing a low coolant temp to register, and what steps am I looking at to "fix" the problem?

I regularly check the coolant level in the intercooler system, my pump is hotwired, and I can hear it running. I can feel the coolant flowing through the lines, although I'm working on doing the soft lines, johnson pump. I would think if anything, on my truck, i would get a high coolant temp, not low.

I'm at a total loss here and as always, will appreciate any input you guys can give me.

thanks!
 

ItsMyTy

Life is beter at 25 PSI
that code is for the ECT sensor, not intercooler system.

check the ECT sensor on the front of the intake manifold, they like to get brittle when old and the plastic comes apart, giving an intermittant connection.

also, unplug the sensor and take a look at the connector for the sensor and make sure it looks ok. could be some bent terminals or lots of corrosion.

if everything looks ok then get a new sensor
 

phoonTy

Truckless. For now.
hmmm. okay. i'll check it this evening after work. i know i replaced that sensor in august of 2002, so it's not even 2 years old yet. i guess it's not big deal though, it's only like $13 or something.

we'll see if the check engine light comes on this morning when i go to work. other than that, sounds like i have some wire tracing to do.

on a side note, any ideas on what could be causing mine to go bad so often? unless i just have some old brittle wires causing false signals?
 

ItsMyTy

Life is beter at 25 PSI
i would put my money on a bad connection at the ECT sensor pigtail

check those terminals on the harness plug in at the sensor

you can get a new pigtail from the dealer to splice in if you find it's corroded or the terminals are spread apart, making intermittant contact

really doubt the sensor is bad since you've replaced it recently
 
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