Air Intake Temp Sensor

hkpierce

'02 140 Hi BlueBlk Pass
From YahooSprinterVan:

#33911 From: Delton Tuchscherer <d_tuchscherer@...>
Date: Fri Oct 13, 2006 11:10 am
Subject: Re: Re: Air temp sensor problems (many)
The air intake sensors marked with blue don't seem to have any issues. The sensors on the recent new vans are plain black.


----- Original Message ----
From: gentleimages <
To: sprintervan@yahoogroups.com
Sent: Thursday, October 12, 2006 1:32:45 PM
Subject: [sprintervan] Re: Air temp sensor problems (many)


Is blue the most recent color? We have had white, brown, and several
other colors. The white ones were the worst. We're going to get a
bunch of spares this time.

We're wondering if we should keep the sprinter after reading about so
many problems with it. But I have no idea what could compare with the
2500.

Sheila
 

abittenbinder

Doktor A (864-623-9110)
This was DCs VERY subtle way of alerting
technicians to the now, all too well known, problem with the type
0M647('04-'06) Intake Air Temp sensor. DC was concerned that symptoms
and DTCs would be incorrectly interpreted as a problem with another
sensor(especially the MAF sensor)-this TSB was the result. They also stressed the ambient air temp sensor being unrelated to engine operation-technicians must have been replacing those as well. The problem with the turbo resonators generated an equally suble TSB- without capital letters and exclamation marks. Doktor A
 
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metalman

New member
Hello everyone,
We have a 05 greatwest sprinter rv van with l-5 and 11,000 miles, second owner.
First off, I am NOT a mechanic, it might take a couple tries, but I normally figure it out. We thought a small 500 mile trip for first outing would be good and on the way home, 150 to go, we get engine light, near by auto store read the code p2199.
They didn't have the temp sensor, it was running but under power, we drove it home just fine. Got on the pc and found these great site, seems I'm not the only one this is happening too. One member said it is a easy fix and travels with extras,
sounded like a great idea, no one carries these guys in stock and most can't even order one. Found a site online,I'm going to order two, they only had one and didn't know when they would be getting more. It's been two months and they are still out, but I got one!! and in it goes.
Off we go one trip two, going rving for 5 weeks in SW of USofA with a code reader, get Phoenix,AZ ,1200 miles, code goes off, wow its p2199,
I don't have spare, found Benz dealer, don't have it and maybe in a couple days, call every auto parts, know one has it, some have no clue. I was near a Checker auto parts, stopped in, young kid was putting 25% into looking for it and was giving up, but a female worker there said let me look, she was on the phone, calling here and there, and hot dam she found one, yes only ONE and I waited 3 hours for that part. She knew a good mechanic down the block and said I should see him as I waited, thanks I'll do that.
Told the mechanic about code, showed him my first temp sensor, His Snap on showed same code, put ohm meter on sensor, he said it should read 5 ohms, it was at 0 ohms, took out sensor in van, it was 0 ohms too. He said on gas engines will run just fine with a bad temp sensor, but did not know why desiel motors ran, but lost power. I said thanks for info, he said no charge, I said lunch is on me and handed over 20 bucks and waited for my part.
If you look at the pic hkpierce put on here, you will see a lite film of oil, that oil shorts out the temp sensor, my bad sensor all look like that one pictured. So why do they get oil on them????? and no my oil is not over filled.
I got my NEW temp sensor and there was no way in hell I was going to just replace the bad one with no spare one and 4 more weeks to go on our trip. So this is what I did, I left the bad sensor in its spot in the tube, but I unplugged the wires to it, I then plugged the wires in the new sensor and I tie strapped in front of the battery. Guess what?? I drove it 7000 miles, up and down mountains, snow and rain, and it ran GREAT, avg.22-23.5 mpg to boot.
I am not changing a thing!!! We love this Sprinter RV!!
But still want to know why oil gets on the temp sensor, sorry for the live story on our rv LOL
 

talkinghorse43

Well-known member
But still want to know why oil gets on the temp sensor, ...
Just trace the path of the engine breather from the top of the engine down to the turbo intake, you'll see that oil from the breather flow will coat the whole intake tract - perfectly normal and not to worry.
 

autostaretx

Erratic Member
Oil doesn't "short out" a temperature sensor.
Oil is -very- non-conductive of electricity.
(stick an ohmmeter's probes into a puddle of oil and see...)
However, i could see that the soot-laden oil that's bypassing the turbo seals could be more conductive than clean oil.
When i measured mine, i didn't see that as the dominant source of failure.

The "room temperature" resistance of the sensor mb uses is about 5000 (five thousand, not "five")
If you had a scangauge, it reports the iat's reading that the Sprinter is seeing
(i'm now on my fourth IAT, the first failed 300 miles into ownership of my 2005 Sprinter,
the next failed one year later... the 3rd one a year after that... and -that- time i didn't have time to drop off the Sprinter for a warranty swap, so i just bought one (my local, dearly departed, Dodge dealer always had them in stock).
Once i'd bought one, i could analyze both the new and old units to see how they worked and were failing.
My last sick one was down around 600 ohms at room temperature, so the Sprinter thought the IAT was about 145F.
(at an ambient of 40F)
Hanging a good one "outside" is certainly one good workaround.
Another $1 workaround is to plug a 5000 ohm resistor into the connector.

As others have posted, the oil coating is "normal"... it may certainly be seeping into the thermistor's ceramic coating and contaminating the actual sensor element.
When i cleaned my sick thermistor, it only affected the resistance by a few ohms (perhaps 550 (dirty) becoming 600 (clean)).

good luck
--dick (now 2.5 years since the last IAT failure)
 

metalman

New member
Thanks to all for the info, I thought it was the oil killing the sensor, I do like the 5000 ohm resistor idea. But since hanging the new one in a safe spot has done the trick. I'll post how long it will last where I have it. I'll keep reading and learning! Thanks again
 

220629

Well-known member
It would be interesting to know how much the Intake Air Temperature deviates from ambient. Correct me if I'm missing something.... Ambient air is drawn through the side of the van through the air filter (no appreciable temperature change), it gets heated going through the turbo (ambient temp +turbo gain), passes through the turbo resonator (if you have one) and tubing/piping (still ambient + turbo gain for practical purpose), to the charge air cooler (ambient + turbo gain - cooler drop), to the intake piping (ambient + turbo gain - cooler drop + EGR gain?) and into the engine. Depending upon how efficient the cooler is you might just be back closer to ambient than might be expected? Remember we're dealing with ambient effect on a relatively hot engine/combustion temperature.

If the above is basically true a sensor hanging out in ambient is better than a fixed resistor. What about taping the sensor to the piping and insulating it? Not as quick a response time, but out of the contamination area and maybe better data than hanging in ambient breezes.:2cents:

That said, I've had no trouble so far with my IAT sensor. (Knock/touch wood) AP/vic
 

baldeagle

Member
I have a year 2000 208cdi. Are all the sensors the same part number? Just got one off Ebay for 99p just taking a chance. Part Number: A651 153 00 28 new in box.
 

metalman

New member
Auqa Puttana, I don't know about air ambient, and I was worried too about just hanging it anywhere under the hood.
But when we were at our friends in AZ on our trip, he opened up a cigar in a plastic tube, he was throwing it a way. I said I need that plastic tube, I cut the tube down and you slide it over the end of the sensor and I then tie strapped it in front of the battery. I did drive it for a couple days without the plastic tube on it, but when I saw that cigar tube, the idea to protect it more clicked in. Through snow, rain and 6000 miles, it is still working great. I'm NOT saying that this is a fix, but I am giving it a try. I just wanted to share this on the road repair, so you can get home or to a dealer, seems that there is something tripping the sensors on some vans more than others.
 

220629

Well-known member
...

I just wanted to share this on the road repair, so you can get home or to a dealer,

...
update
Well we put on 30,000 plus miles with the so called sensor fix, still working great.
You really need a GPS. 30,000+ miles and you still haven't made it home or to a dealer??? :tongue:

Seriously, thanks for the update. Not that it really matters, but have you tracked fuel use? vic
 

gggGary

gggGary
kind of mid stream but I had posted on the "other side" and got booted out.

Syopsis; ecm light is on pretty regular I have a DAD the code I am getting is P2032 upstream O2 sensor TWC (KAT) Van runs but lacks power.
While clutching at straws I did a pretty thorough check out of the IATS and it is normal in all respects. ohms vary with temp, 11K in ice water on down to 5k at room temp in accordance with the chart. I have +5volts on the hot wire and ground on the ground. One of the DAD module's live data streams shows the correct IAT temperature now. DAD is bit flaky connecting not connecting, showing, not showing, showing some data streams. I will have to test drive the van tomorrow. I did get a coolant temp not present warning but on a rescan and wire wiggle that was gone. So more testing tomorrow evening maybe.
Methinks i need to pull and check out the upstream O2 sensor where ever that is.
Thanks for all the help so far.
 

220629

Well-known member
kind of mid stream but I had posted on the "other side" and got booted out.
I hear you. Those "other people" can be tough. :lol:
Syopsis; ecm light is on pretty regular I have a DAD the code I am getting is P2032 upstream O2 sensor TWC (KAT) Van runs but lacks power.
While clutching at straws I did a pretty thorough check out of the IATS and it is normal in all respects.
...
I was wondering how an O2 sensor code took you to the IAT. Clutching at straws makes sense. Been there... done that.

Methinks i need to pull and check out the upstream O2 sensor where ever that is.
Thanks for all the help so far.
There is only one O2 sensor on my 2004 T1N that I know of. I don't think it's upstream because it's in the exhaust pipe. I need to remove the aluminum heat shield to access it.

I've never seen more than one each listed for T1N parts. Let me know if you find another one somewhere. vic
 

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gggGary

gggGary
Thanks for the help and great tech postings AP. Methinks "upstream" refers to located before the cat. If I remember correctly many gas systems have an "upstream" and a "downstream" sensor located before and after the cat, so in this case upstream means "before the cat". My latest straw to clutch at is that my glow plug circuit is dodgy, some glow plugs heat some don't, I think perhaps I have dirtied up the O2 enough during last winter's starts that it is giving the ECM bad numbers and the ECM is giving the low power drill like it does with a bad IAT sensor. My next plan is to remove, look at and perhaps clean the o2, after that, if it keeps throwing codes, replace it. I see they use some fancy damned thing so I cant just wire some cheap ebay O2 sensor in as the fix. I will move this and subsequent info over to a new "P2032 code" thread.
 

220629

Well-known member
AP,

wheere did you obtain the book that you're posting from? I'd like to purchase one.

thanks
This is an automated response.

The 2 each spiral bound books are titled:

2001 - 2006 VA Sprinter Body Electrical

2004 - 2006 VA Sprinter OM647 Diesel Fuel System

There is no ISDN number or other ID.

Jon said they came from Tech Authority. He also said they were expensive. You could contact Tech Authority and ask by title I suppose.

Tech Authority Website

https://www.techauthority.com/en-US/Pages/Country.aspx

I selected "Dodge" and then used "Sprinter" as a search word figuring that would get all the hits.

The descriptions with the red color training manual for a picture seem to be like the spiral bound books I have. I didn't notice any VA series, but there was a VB gas engine training book.

There is a free book Jon pointed out to me here.

https://www.techauthority.com/en-US/Pages/ItemDetail.aspx?itemID=1022&catID=106

Use the flipbook link in the lower left.

Actually the fuel system CD which Doktor A started offering is the same format as my books and contains much of the same information. I recommend that book (on CD). Sprinter Hot Line 864-623-9110. Doktor A

Please don’t contact JD Caples (Jon) because he has no more information than I give here. He really does deserve mention and credit for giving me the books with the thought that I would help people by using them. The books just may not be available anymore?

Sorry I don't have more. vic
 
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metalman

New member
Just wanted to let every one know, air intake temp sensor is working GREAT,
48,000 miles and it is still tie strapped in front of battery, with old one still in intake tube.
 

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