P0117 Code on '06 V6 4WD

After driving around town today off and on for about 150 miles, I suddenly had steam coming from my engine compartment. I found the overflow reservoir cap blown off and the steam was escaping from it. The Check Engine light had been on for about the past 200 miles, but shortly before the loss of fluid, the light had gone off for about ten miles, and then it came back on. The engine temperature gauge was showing normal operating temperatures the entire time. After slowly adding water to limp back home, I stopped at a auto parts store to check the code and got 3 different P0117 codes. The only difference is that the first one said "current"; the second one said "history" and the third one said "confirmed" (see images below). I don't understand this.

When I got to the parts store approximately 5 miles from first refilling with water, the overflow cap was blown off again and it was blowing steam again. I decided to fill it again, this time with diluted anti-freeze, and I hoped to limp the remaining 15 miles home. This time I ran the heater full blast as I drove. I stopped at another auto parts store about halfway home expecting to need to fill it again. This time, it appeared to have lost no fluid, as the overflow reservoir was full of the antifreeze I had added and the reservoir cap was in place. When I arrived home, it still seemed to have not lost any more fluid.

By the way, the temperature gauge didn't seem to move from its normal range even after I slowly filled it with water over approximately 30 minutes. Also, I guess the guy at the auto parts store reset the check engine light, as it was no longer on and it didn't come back on again.

• Does this seem to really be the Engine Coolant Temperature Sensor (ECTS), and not the thermostat?
• Is this sensor a tempermental electronic device that can fail intermittently and then mysteriously start working again?
• If it is the ECTS, must I remove the manifold to replace it?
• If I don't need to remove the manifold, is it a relatively easy job to complete?
• I have seen other posts about this, but it seems many are specific to the 4 cylinder engine not the V6, so I am posting relative to the V6.

Thanks in advance for your help!

 

Sorry for the huge images. I thought I was only posting thumbnails.....

Mods, if you can change to thumbnails, please do so.

 

On a cool engine. With the key On, engine OFF, what does your scan tool say the ECT is reading?

The 3 codes are normal.
You had the code in history (past), you have the code now, and code confirm in mode M$00.

 

Thanks for the response. I don't have a scan tool, so I may need to go buy one. I do have a Forscan adapter for my F-350 and the app loaded on my computer, but don't know if I can use that on my Taco and if so, if the adapter I have will work. I'll have to do some searching to figure that out.

 

I purchased a code scanner and with the key On, engine OFF I am getting one P0117 code (stored), and I am also getting a P0420 (pending) code.

 

Look at live data, and see what the coolant temp is reading Engine off, key on , cool engine.

 

Apparently with my Innova OBD II scanner, I need to connect to my smartphone via bluetooth in order to get live data. This should be easy and uncomplicated, yet Innova has made their app, the user interface, and the process of connecting via bluetooth very difficult and user unfriendly. I have followed their instructions to the letter and cannot get their scanner to perform the simple operation of connecting via bluetooth, so I have contacted their support team both by phone and by their online chat support and am waiting to hear back from a living breathing human being. I imagine you can sense my frustration in this post.

More will be revealed....

 

The only reason I ask is if it show like -40 or +270 degree we have an idea where the problem is.

The strange part is, you are apparently over heating yet the temp gauge says you temperature is “normal”. Is this correct?

The temperature gauge reads normal when the over flow blows the cap off?

 

You are correct on all counts. As I slowly added water and let it gradually circulate through the engine so as not to crack a block, I closely watched the temp gauge. I was surprised to see it didn't move from the normal position at all. It also remained the same when I added the diluted anti freeze. When I stopped to check it the third time, the overflow cap was still in place and it didn't appear to have lost any fluid.

You got me thinking, so I just went out to see what it says. It is now pegged on cold, which makes sense, as I haven't warmed it up since I got home and parked it Friday night when this debacle started.

 

Finally got a reading after buying another scanner. The first one was supposed to have live data, but after about 2 hours of trying to connect via bluetooth and finally talking to a living breathing human being at Tech Support, I was advised that despite their claims on their website, the model I chose didn't have live data.

Anyhoo, the ECT is reading 275 °F while the truck has not been warmed up for 3 days. The ambient temp where it is parked is currently 37 °F.

Houston... we have a problem.

 

Unplug the ECT sensor. If the temp stays the same, It is NOT the sensor.
If the Temp drops to like -40, its the sensor.

 

Thanks. Too dark and cold tonight. I'll check it tomorrow. I appreciate your prompt reply!

 

No problem.
Same here, I'm a fair weather mechanic myself too.

 

I am trying to figure out where it is. Is it tucked behind the passenger side cylinder bank?

 

It's not in a fun spot, it's on the coolant crossover manifold at the rear of the engine.

 

Ouch. I am getting too old and fat to do that kind of stuff.

 

See here for pics and more
https://www.tacomaworld.com/threads...-you-get-to-this-sensor.813612/#post-29180403

 

Yea if you pull the heads off it's right there

 

I wish I had a good excuse why I can't do stuff.
Is "I don't want to" good enough.....

 

Works for me!