P1110- the code that wont go away!!

[CanuckQx4]

Could a faulty coolant temp sensor cause the hard starts Im having??

So this is a mighty job on its own for me in my driveway. Ive had the upper half of the intake manifold off, and Im fine with that, its digging to something that I cant even see let alone feel, on my own kinda worries me. As Im sure you can already tell, Im just trying to do my best with limited knowledge just alot of drive to have a nice running Nissan!!

Would the oem sensor happen to use a standard pipe thread? Maybe I could buy a new oem sensor, but install and wire it on the T in my upper rad hose that I have for my aftermarket temp gauge?? And make it function as stock or does it need its reading from that specific point? Could hold me off til summer weather

My temp gauge jumping to almost half as soon as I turn the key is getting quite bothersome though

Im open to anything right now, especially further diagnosing this sensor if I have to, or if you think I should just go ahead and replace it.

Happy wednesday

[SteveTheTech]

What does your other gauge say about the temperature?

Was there ever a P0115 or P0217

Getting an erroneous reading is one thing. Could be a separate electrical issue, unless there was a dtc.

Before you pull anything out check the resistance of the sensor.

Adding a gauge sensor elsewhere will not work at all. The temperature swing in the system can and will throw off an add on gauge.

[CanuckQx4]

It DID throw a P0217 Engine Overtemp Condition last week

The car was cold started from -10 and I was trying to get air bubbles out of the system, it threw that code at 110degrees, maybe 10 min of idling and the rad was full the entire time. I cleared it about 50km ago and it never came back in this weeks commutes to work

Ok Ill check the resistance of the male pins of that connector, in the morning I guess its 4:30am

Actually, maybe I should check that now since the engine will still be warm hmmm

bundle up

[CanuckQx4]

I checked resistance today on the male ends, weird readings.

I would only get my meter to change form "infinity" when touching the #1 and #2 terminals, and even then it gave a reading Ive never seen before. It usually reads .5 / 1.5 / 14.7 or whatever.

But it displayed 001K (then an ohm symbol dont know how to write that)

I did the test after running the car for 5 min, temp of coolant was about 80*

[SteveTheTech]

Is that -10C?

I cannot fathom an overheating vehicle in temperatures like that.



Here is the reference chart for that coolant temperature sensor.

I wanted to see what you had as a reading but I am not encouraged to see the results. Lets keep in mind the decimal point and symbol next to the ohm sign mean a great deal here.

The 001K ohms was most likely preceded by a decimal point which would make the reading plausible, bad but plausible. The reading would be converted to be easily read. One one thousandth of a K (thousand) ohms would equal 1 plain old ohm.

Loooking at the chart thats about 2 thousand ohms is considered minimum when completing the circuit. Think about how a DMM measure resistance. It sends a minuet electrical charge through the circuit and measure the opposition of electron flow. You always have to connect the leads in series (complete the circuit).

Kudos to you on your determination or stubbornness.

[CanuckQx4]

Yes it was -10C, very cold here where I live in canada, was -17 today plus wind chill, she definetely wasnt overheating.

I was a little stumped on the reading aswell, Ive never seen it show a display like that. But there definetely was no decimel point on the display at all, I put the positive lead on the furthest left male pin, and the negative on the middle male pin. It settled on 001k everytime, while any other combination including the 3rd pin or any other combos resulted in no reading, only got that number when touching 1 & 2



If youd like, I can do the test again with the car at operating temps and just shut it off and do the test right away?

Whatever makes this work, thanks for applauding my stubborness, I hear that alot, kudos for returning and helping me through this.

I want to buy things for you

[SteveTheTech]

I think at that temperature your "huevos" would literally freeze. That alone could mess with even a normally running car. I guess I should stop complaining about it being ~-1C.





Try this and let me know what you get.

[CanuckQx4]

Few new things today, I was a little irritated by my test leads of my DMM being so short, so I bought some 4foot leads. When the DMM is set to resistance and I touch the leads together, it shows .36ohm. So my resistance numbers will already have that ammount subtracted.

First I did the voltage check on the female end of the connector with the ignition ON

Red/Green = 4.82 V
Black = 22.1mv
Red/Yellow= 1.65 V

Then I went to check the resistance of the male end pins of connector F112 between the red/green and black pins. And got .207 ohms, this was with my aftermarket temp gauge reading about 100* farenheit

Then about 5 min later I checked again, dont think I checked the temp gauge this time, and got .340 ohms, and I held the test leads on the pins for about 30 seconds and watched the number climb and climb gradually about .001 every 2-3 seconds

I also did a little snooping for the actual temp sensor itself trying to follow the harness unsuccessfully back to the sensor, dont think I even came close lol. Not looking forward to that job if it indeed is a coolant temp sensor failure.

EDIT- and for kicks, I tried with my old test leads again on the resisitance, and got the same bunk number as yesterday, so I think those leads had seen there days. Glad I spent the $14 on new ones today

[SteveTheTech]

Few new things today, I was a little irritated by my test leads of my DMM being so short, so I bought some 4foot leads. When the DMM is set to resistance and I touch the leads together, it shows .36ohm. So my resistance numbers will already have that ammount subtracted.

Then I went to check the resistance of the male end pins of connector F112 between the red/green and black pins. And got .207 ohms, this was with my aftermarket temp gauge reading about 100* farenheit

Congrats on the new leads. You have less resistance in yours than I have in my several hundred dollar Fluke leads.
I also think my meter is getting a old.

Are you sure about your scaler there?
.207ohms is nothing .207K ohms is good for 100F according to the chart above.

Today in Washington DC is was a high of -15C w/o the wind. That kind of cold just sucks.

[CanuckQx4]

Oh sorry I guess I wrote that wrong, I didnt notice a K on the screen next to it, but its was 3am and snowing, so I might have just not noticed it while jotting down the numbers

Does that somewhat say that the sensor may be good? That graph to me says that at 100 farenheit it should have read like 1.5 ohm, my purple dot is where I figured my reading was



I dont know if I typed this or not so I'll write it again. Even though I havent ran the car all day today, if I were to go turn the ignition to ON, the temp gauge would go to 3/8ths the way up the gauge towards hot, even though its dead cold and should be at the bottom I figure

[SteveTheTech]

Oh what the hell, I looked at it wrong, my decimal point was off one. ha

What happens if you disconnect the the blue connector and turn the key on?

Next step would be performing the checking the gauge.

[CanuckQx4]

With the ignition ON, gauge goes to just under half, when I unplugged the connector in the engine bay nothing changed on the gauge. Stayed in the same place

Then I looked in the FSM for a meter gauge check and found one on pg100 in the EL section of my 01 manual. I did the test and the gauges all jumped to half mass like the test said they should. So I think the gauge cluster itself is fine.

I emailed my friend about this problem as hes pretty good at reading the manuals a few weeks ago but hes on deployment but he got back to me tonight and said this.

"The connector looks to be on the passenger side above the valve cover near the firewall, which is Sky Blue and should have (at least) the following wires:
yellow with red stripe. This goes to the "thermal sensor" which runs the temperature gauge. This is the one you care about.
light green with red stripe. These next two go to the "engine coolant temperature sensor" which is an input to the computers that run the engine and transmission.

You likely have a wiring fault somewhere between the instrument cluster and that plug. It looks like that wire runs a short distance forward and joins a fat (1" OD) cable then runs in the fat cable back to the firewall, across behind the engine, then through the firewall.

Start with the car cold.
Turn the ignition on, but don't start the car.
Give what you say above, the temp gauge should read half.
Now unplug the sensor.
If you have a bad sensor, the gauge will go to zero.
If you have a short in the wiring (other than the bit from the plug to the sensor),
the gauge will stay the same.

Cheers buddy let me know"


I dont expect a reply from him anytime soon but I told him the same info I posted above. Seems were onto something!! My fiancee wants to just start throwing my money at the car, but I feel this coolant temp reading being off could be affecting the cars performance, so Id love to resolve it and there see where it leaves me with any outstanding codes.

Thanks Steve

[SteveTheTech]

Seems like we are working toward the same thinking here. Now you get to get into harness diagnosis. This type of stuff is not easy to do remotely. This is the first time I can think of trying to attack an issue like this with and you knew this wasn't going to be easy.

Do you have any electrical add on or a history of main harness alterations?

Something like a damaged main harness could be route cause of some if not all of your problems. Unintended consequences can be an SOB.

We have been slowly trying to rule out the easy things now it gets fun.

You still might have a timing issue, or an actual over heating problem. I think we are getting strayed from the original topic or are we just moving onto something different?

Have you ever had a water leak?

[CanuckQx4]

Well I can safely say that I havent messed with an OEM wire myself since I owned the car other than the washer fluid pumps (solderred new pumps and wires, works perfect though).

And the gauge used to work fine for quite some time after we bought the vehicle, I think one day it just went loopy on me, but there may be a pinched wire or something.

Is there a common wiring section that could be damaged that could cause all my issues electrically?
passenger front 02 sensor tripped but hasnt come back
P1165 was something about inactive fuel trim, hasnt returned this week though
temp gauge reading high
P1110 solenoid

Ive never had a water leak I wasnt aware of, and I definetely never drove with one. As far as I know timing has never been touched, the truck has never seen a dealer or service station since I owned it. I try and do everything

I havent even attempted to go full throttle in a while until I get some problems resolved (Im back to using an oem MAF sensor just heavily cleaned) but I have a feeling it still is very sluggish on the top end for some reason, falls on its face after 4k rpm. I only drive the truck 50km a week so I dont think I even give the car much time to think or cycle lol

Today Im actually taking my aftermarket water temp gauge out, I want an OEM upper hose, and hopefully I have better luck getting ALL of the air bubbles out. My vacuum coolant tool you recommended should be here, and oem spring clamps

Is there a way I can maybe test rig a wire from the coolant sensor to the ecu or gauge cluster to check if a piece of wiring is faulty in the harness? Or another best way to do that? I cant see any pinched wires anywhere, possibly a faulty ground controlling all of these?

[CanuckQx4]

Could there possibly be a bad ground or a common wire circuit that could cause this temp sensor gauge give false readings, aswell as my swirl valve error, and even possibly P1110??

I checked what I could see against the firewall for wiring or any chance of any pinched wires when I did my plug swap or took my plenum off to tighten the swirl valve screws, but didnt see any damaged wires or any chance of anything being pinched, but I only looked from the top, both sides.

Just a thought

[SteveTheTech]

You might very well be onto something.





Check the brown connector under the radio. This is a common connection point between the main harness and engine control harness. If there were corrosion on the connector illustrated in the first picture, although it may be hard to see it looks like it is under the radio. From the outside you would follow the engine harness to the bulkhead and then continue from the inside looking for a large brown connector.

Fingers crossed, there is green moss looking crap inside of there.

Oh and heres another M32 related system

That may impact your WOT issue

Oh and the O2 sensor heater issue, I thought I remember you talking about...

If the connector passes your visual inspection we will need to isolate the segments and figure out the issue.

[CanuckQx4]

Thats nice to hear!! Will I have to remove the radio and front of the dash to get at that or is it accessible looking under the drivers side or passenger side footwell?? That diagram looks like connector may on the drivers side of the center

I'll definetely be checking that after work, other than green moss and cleaning the connector best I can if I can find it with electrical cleaner, should I tighten the connecting pins if possible?

[SteveTheTech]

Your guess is as good as mine on the location of the connector. The image is a vague 3d image you have a general area and a connector color. My suggestion would be to remove the front finisher piece and radio and look down. Today I would only perform an inspection and unless you see something glaringly wrong put everything back and let me know. Pin adjustment is not recommended unless there is a proven issue.

Next we will work on a few test and conditions to test the circuits that run though this connector, but this is directly connected to the computer. There have been a few quick shorts to the ECM already and we should try to minimize these.

[CanuckQx4]

Ok I will take an early lunch and pop the radio and trim pieces off and see what I can see. Looking for a 24 pin brown connector, gotcha

Thanks!

[CanuckQx4]

Found it, removed the radio and seen a brown plug off to the left tucked away, couldnt access from that point so I took the lower part of the dash off under the steering wheel.



Appeared in perfect condition but I disconnected it to look anyways, and it looks perfect inside aswell. Almost wanted to see corrosion

[SteveTheTech]

Appeared in perfect condition but I disconnected it to look anyways, and it looks perfect inside aswell. Almost wanted to see corrosion

Damnit yeah me too.

Back to the manual. At least you know where it is we might need that.

It still might be something similar still there are too many things that happen to run through there not be raise a few flags. But...
ARGH!!!

I wish you had another engine computer to try.

Next time your under there near that brown connector remove and inspect the ECM connector which is right near there. Just for fun.

I'll mull this over when this afternoon.

[CanuckQx4]

Thanks, does the engine ECM happen to be the white connector 2" to the right of the brown, you can barely see it in the picture, I believe that was the only other major connector I seen in the area. I left it unassembled since I ran out of time on lunch, so I guess Ill leave it that way for now

I just checked ebay for engine ecm's, and there are 2 listed in the $200 range, would that be an avenue worth exploring?

[SteveTheTech]

You found the ecm. The connector is locked in using the black clasp. It's kind of a PITA to unlock and remove the first time so doing that at work might not be the way to go, just in case.

I wouldn't recommend a questionable guess on an ebay computer just yet.

It's probably time to test some of the ecm signal.
check out ec-127 start with power supply and make a list of what you get where. Since we have little data monitor ability we
have to verify signals must be done at the source to prove what is actually working.

[CanuckQx4]

They dont seem like tests I can preform outside in this weather so I will clean up the garage and bring it in I suppose to try this out, the tests seem a little advanced for me, but Ill read it over many more times and see what I can accomplish thanks.

[SteveTheTech]

I know I'm havin a hell of a time working on a few simple tests we can knock out. I wanted to give you some idea of what we are working with. This is getting into some pretty advanced stuff.

It really sucks at this point it would seem that if there were a common issue it is going to suck and probably be expensive and difficult.

I'm still working on a few things I'll get back to you most likely in the morning.
Cheers

[CanuckQx4]

Well Chuck was helping figure out why my temp gauge was reading wrong, and asked me to check this:

"Measure the resistance between M24 pin 16 and ground. It should show an open circuit (same as holding the probe in air)."

I did that test by disconnecting the coolant temp sensor connector in the engine bay, and the gauge cluster, and probed that Pin#16 (YLW/RED) and I showed 137ohms resistance, not open like it was supposed to be.

If that perhaps narrows down what path and place the wiring fault could be at I thought I would mention it.

[CanuckQx4]

Car threw a P0115 today, first time Ive ever seen that one I believe.

P0115 Engine Coolant Temperature Circuit Malfunction

Havent done much on the diagnostic myself, we got 10" of snow here today, and aparently another 10" tomorrow!

[SteveTheTech]

Hey man sounds like your having some fun there. I've had a hell of a week thus far but only ice so far.

137ohms sounds a little odd. If it were a short you would think it would be more resistance.

Did you plug the sensor back in?
-Sorry hate to question but I can't see

What was the gauge doing?

The next step in the resistance test is to break the suspect wire into smaller segments.



Next I would isolate the combo meter and M33 pin 4.
M33 is located right next to the brown connector under the radio.

[CanuckQx4]

No the sensor was disconnected when I got 137 ohms

He told me to disconnect the sensor harness in the engine bay, disconnect the gauge cluster, find pin#16 (YLW/RED) from the big harness behind the tach on the gauge cluster and probe it with positive, and ground the other probe. It should have said no resistance as that wire wasnt plugged into anything as both ends of the harness were disconnected, but I showed 137 ohms resistance

Unless I messed that test up

[SteveTheTech]

No you didn't do anything wrong. You performed a short to ground test.

The next step is to go from the disconnected female blue connector terminal 1 to the yellow/red wire.