REPLACE CHT SENSOR?

2016 F150 4x4 Crew Cab Platinum 5.0 engine. Just under 60K miles. Regular maintenance done. Coolant was replaced on schedule.

I was gone over Labor day for 4-5 days. Truck is in garage. I try to drive it when I get home and it wont start. I needed to get somewhere so diagnostics at the moment was out. But figured the obvious. I jump it using a battery jumper and it starts right up. Drive it around but clearly when I start it over the next few days it seems weak. So I get around to multimeter and voltage if 12.36. Overnight it drops to 12.16. Still will start but clearly something is not right. Battery is 5 years old so I go to auto parts store. Cleark looks me up and says "Wow that battery is old (2020)." Ok, so I replace the battery and everything is fine for about 8 days or so.

Yesterday, I drove to an appointment about 10 minutes away. After my appointment I'm in parking lot idling as I have another appointment in 45 minutes but it's like 5 minutes away. I idled for about 10 minute then drove over there. I'm almost there and I get a coolant over temp warning and my coolant temp gauge shows nothing. I pull into parking lot within about 5 minutes. I shot down truck and wait for 10 minutes while I look up possible causes. I open hood, inspect reservoir. Seems fine. I power up accessory mode, temps look good. That's weird. I have code reader in the car. I pulled off 4 codes. 3 are obviously related to bad battery (which surprised me). 1 seems related to coolant warning and it is code P1289. (And yes I know what the code is) I decide to clear the DTCs (after seeing reports matching my symptoms).

I go into appointment and come back 30 minutes later. I drive for about 20 minutes and no problems. I park and go to an event for 2 - 2.5 hours, and drive home 15 minutes. Still no problems.

I took it to shop this morning about 10 minutes away. Still no problems. Shop can't find anything wrong so far. It's not kicking off any codes. (Which I figured would be the case).

I'm thinking I should just proactively replace the CHT sensor just because I don't want this happening again. But right now no codes are popping and nothing is happening. So sensor is obviously fine right now. Dubious it is wiring but that has to be checked. Sensor fixes this problem 99% of time according to some diagnostics videos.

I'm wondering if the low battery ruined the sensor or just caused problems but now they're clear. But the coolant warning came AFTER I replaced the battery. Proactive replace it or wait for sensor fault again?

Thoughts?

 

Well, you need some education on how to handle the trucks faults.
First your post, says there was a total of 4 codes set and only report one.
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Apparently, there are two or more separate issues.
The 1289 likely is an intermittent CHT Sensor or wire issue.
The CHT Sensor is located on the rear of the passenger side Head. Access is through the wheel well area. Once disturbed it should be replaced due to its design and location. There is no coolant directly involved.
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The other 3 codes might be for other faults including the charging system.
Don't just clear codes and/or dismiss them because clearing does not repair or reset any fault.
If the codes return, what are they? You need to know what systems they point to for repair.
Dealer would tell you the same thing.
Good luck.
.

 

I appreciate your cynicism and ego.

I cleared the codes because I knew what I was doing. I already knew the codes and why they’re faulted. In fact, I said as much when I said they were related to the battery.

And I would not take my truck to a dealer unless that were my only choice. Their diagnostic fee would cost more than the work at a reputable mechanic.

I already know what the code means. I told you what it means. It’s related to the sensor. The question is whether I should replace the sensor proactively. I’m unsure whether it can be a one time event that could be caused by a bad battery swap or a sign it’s definitely gone bad.

 

In a post like you made, one does not trust what you think all code mean.
We don't know if you did or not without posting them so others could learn.
If you're under control of everything, why post it?
I took you post at face value,
You object to it.
It took 2 hours before I answered as no one else gave it a try, SIR!
Just the way it goes sometimes.
Good luck.

 

It fascinates me why someone who knows what they are doing and knows what the codes mean cannot decide (on their own) if they should preemptively change the coolant head temperature sensor. @Bluegrass gave good advice but you dismissed it. It appears that whatever advice you are given, you will ignore it. There aren't any magicians here, the knowledgeable people here need all of the information, even the deleted codes, to provide credible help. Suit yourself "sir".

 

you have toi start with a good strong battery otherwise you cannot do any other diagnostics these trucks will throw codes and flash every light on your instrument cluster due to a weak battery it is so bad that if you get a flat tire i would suggest checking the battery first install a new fully charged battery do the bms reset and go from there driving and idling for 5-10 minutes is not sufficient to fully charge any battery if you do not drive a lot add a battery tender

 

He nor you have given any advice. What I'm asking for are people who have had experience with this sensor and its failure. What are the possible causes and the potential time frame. None of that was addressed by either one of you.

So if you're going to give advice, maybe give advice for the subjects being sought instead of berating the OP over issues he didn't seek counsel.

 

This is not about what I think the codes mean. That's not what I asked. I know what the codes mean. A one time sensor fault doesn't mean there is a bad sensor. It could mean the sensor fault was caused by other issues. My question is strictly about those who have issues with this sensor and what their experience was.

For example, this is the type of thing I am looking for. I am not looking for advice on what the codes meant.

 

I went ahead and did proactive service. I replaced the sensor as a strictly precautionary measure. It probably wasn't necessary but I think $100 was worthwhile for peace of mind. I also did coolant flush, inspected wiring, and with a new battery that should cover every possible base.

 

My "advice" was to post ALL of the codes to minimize guess work because you didn't understand what @Bluegrass had said. You "sir" like to complain and that is about it. Advice from others was to make sure your battery is Fully Charged and buy a battery tender if you don't drive enough to keep the system Fully Charged. You have done nothing but complain.