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ecowhale
04-04-2017, 06:38 PM
I'm in need of the Ohm reading for the EGR temperature sensor wiring harness in the photo shown below so I can get a resistor of similar Ohms as I cannot install a sensor on the EGR due to EGR cooler damage.

If that didn't make much sense, my EGR cooler has damage where the sensor connects and I cannot re-install a sensor there, so I need to attach a resistor to the harness where the sensor connects to fool the ECU into thinking the sensor is there.

This is for a 2007 Dodge Sprinter, so any 2007+ reading should work (preferably 2007).

Thanks

autostaretx
04-05-2017, 01:04 AM
Didn't i post a few thermistor curves in your earlier thread?

Pick the temperature you'd like it to think it's at ... read across the graph and there's the resistance.

OR: tell us what temperature you'd like it to think it's at.

--dick

autostaretx
04-05-2017, 01:22 AM
I forget... did you measure the resistance of your current sensor?

If it was above 200 ohms, then these values might work:
Temp Resist
68 F 3000 ohms
104 F 1300 ohms
150 F 500 ohms
200 F 250 ohms
250 F 100 ohms

--dick

ecowhale
04-05-2017, 04:57 AM
I forget... did you measure the resistance of your current sensor?

If it was above 200 ohms, then these values might work:
Temp Resist
68 F 3000 ohms
104 F 1300 ohms
150 F 500 ohms
200 F 250 ohms
250 F 100 ohms

--dick

Thanks, but I'm not advanced enough to know what to do with that info, all I know is to buy a resistor and solder to the wire harness (2 wires). I just need to know which resistor to buy available on Amazon for example. They have a lot of them for sale there. Then I have to know which end of the resistor gets soldered to which pin.

Otherwise I would have to spend about $150 for a new sensor. Expensive due to being made in Germany, but obviously could be made in China for 1/10 cost and probably made better.

autostaretx
04-05-2017, 04:26 PM
If it was above 200 ohms, then these values might work:
Temp Resist
68 F 3000 ohms
104 F 1300 ohms
150 F 500 ohms
200 F 250 ohms
250 F 100 ohms
Thanks, but I'm not advanced enough to know what to do with that info, all I know is to buy a resistor and solder to the wire harness (2 wires). I just need to know which resistor to buy available on Amazon for example. They have a lot of them for sale there. Then I have to know which end of the resistor gets soldered to which pin.
You have to pick which temperature you'd like the ECU thinks the EGR is at.

Let's say that you choose 150 F. Then you'd buy a 500 ohm resistor. (resistors come in various wattages... anything 1/8th watt or higher (1/4, 1/2) would work).
I'd go to RadioShack (there are still a few around), Fry's, or any stereo/computer fix-it place.

Since it looks like the sensor has pins (instead of holes), that tells me that the cable's connector probably has holes... instead of soldering, i'd just poke the resistor leads into the connector's holes and tape it in place.

Resistors do not care which end goes into which hole.
Otherwise I would have to spend about $150 for a new sensor. Expensive due to being made in Germany, but obviously could be made in China for 1/10 cost and probably made better.
If it's like my IAT sensor, they're using a Seimens thermistor held in a plastic holder.
My IAT sensor is about $30 or so. (i haven't looked recently).

The ECU knows what to do if it doesn't see a sensor in place, or if it thinks the sensor wires are shorted together or to ground. Giving it a resistor to chew on will (instead) confuse it. I'm certainly curious as to how well it will perform and whether or not it'll throw a different error code and/or turn on the CEL light again.

good luck
--dick

sprint2freedom
04-05-2017, 04:38 PM
If it's like my IAT sensor, they're using a Seimens thermistor held in a plastic holder.
My IAT sensor is about $30 or so. (i haven't looked recently).

The ECU knows what to do if it doesn't see a sensor in place, or if it thinks the sensor wires are shorted together or to ground. Giving it a resistor to chew on will (instead) confuse it. I'm certainly curious as to how well it will perform and whether or not it'll throw a different error code and/or turn on the CEL light again.

The Sprinter ECU seems to care a lot about whether sensor readings are "plausible" and tends to throw codes when they are not. It may be smart enough to see a fixed resistance value as an indication that the sensor has failed.

For the money and hassle of a potential stranding later on, I'd pony up and replace the sensor, but I too am curious how this turns out..

avanti
04-05-2017, 04:38 PM
My best guess is that you will get a "plausibility" fault if the perceived temperature never changes. It is one thing to spoof the thermistor that controls the display on your dash or the Espar heater, it is another matter when it is in an engine-control loop.

Good luck, though.

OrioN
04-05-2017, 04:50 PM
:wtf:



:popcorn:





.

ecowhale
04-06-2017, 07:04 PM
I too am curious how this turns out..

Since most of you are very curious if tricking the ECU with a resistor will work or not... the answer is... dom dom dom.... YES!, the CEL is off... see photo. I used a 470 Ohm 1/2 watt resistor based on Dick's info (thanks, Dick [Ohm suggestion] & GDE [resistor idea]).

Since the CEL often comes right back on upon second time the vehicle is driven, I drove more than three times, no CEL!

This saves me up to a few thousand dollars! in parts and labor as well as a few days down time vs. replacing the EGR cooler and sensor (if the same code doesn't reappear.

sprinterthad
05-18-2017, 08:11 PM
I have a question. I believe my ERG heat sensor might be bad. Using the figures above, the ohms lower as the temp gets hotter. Mine does the opposite. I tested it cold (70 deg f) and it read 248 ohms. I then heated it up (using a propane torch) and the ohms raised, not lowered.. Is that correct? The highest they went were 500. Any opinions?

Munmile
05-18-2017, 11:33 PM
I have a question. I believe my ERG heat sensor might be bad. Using the figures above, the ohms lower as the temp gets hotter. Mine does the opposite. I tested it cold (70 deg f) and it read 248 ohms. I then heated it up (using a propane torch) and the ohms raised, not lowered.. Is that correct? The highest they went were 500. Any opinions?

It's probably a PTC thermistor not a more common NTC thermistor. PTC was probably chosen for the higher temp range it must live at.

cheers
Munmile

autostaretx
05-18-2017, 11:37 PM
I have a question. I believe my ERG heat sensor might be bad. Using the figures above, the ohms lower as the temp gets hotter. Mine does the opposite. I tested it cold (70 deg f) and it read 248 ohms. I then heated it up (using a propane torch) and the ohms raised, not lowered.. Is that correct? The highest they went were 500. Any opinions?
Bad thermistor

When my IAT sensor died, i tested both the old and the new part.
The new one responded as the curves suggest: about 5000 ohms at 68F (20C) and lower when hotter (to 212 F). Dipping it in ice water raised it to 6000 ohms.

The bad one was at 600 ohms at 68F, and didn't really respond much to reasonable heat or cold.

"negative temperature coefficient" (NTC) Thermistors are far cheaper than PTCs, and are what's usually used for measuring temperatures below 200 C (think 400 F).

--dick

edfrompa
05-18-2017, 11:50 PM
[QUOTE=ecowhale;543063]Thanks, but I'm not advanced enough to know what to do with that info, all I know is to buy a resistor and solder to the wire harness (2 wires).


Maybe this is not a good DIY project for you!

lindenengineering
05-19-2017, 02:03 AM
[QUOTE=ecowhale;543063]Thanks, but I'm not advanced enough to know what to do with that info, all I know is to buy a resistor and solder to the wire harness (2 wires).


Maybe this is not a good DIY project for you!

Maybe this is not a good project mod for anyone!
BUT Its all down to the road to no re-gen and frantic posts about doing EGR and cooler deletes because the bloody thing isn't running right!
:laughing:

All i can say from where I sit its great for business !
Plus its great for college education.
One daughter degree in Bio Medicine at Georgetown U Thanks to Ford F250 Superduty
One daughter a medical doctor degree with Hons--UMTB Galveston--Thanks to Bavarian Money wasters & Landrovers ! ( and for those charges in tuition fees extended thanks to BMW and the crap you build! 3 and X Series wow! )

Now along comes #2 son just graduated & wants to study mechanical engineering!
Neglect & botch ups of light duty diesel engines is the source of the next education expense wave I suppose --Guess what brands ?

And i have yet another young daughter and my youngest son who want to be a big animal vet! Crikey have you seen the college tuition fees??--London Royal Vet College is obscene!! More than a Med doctor!!!
Keep dicking them up guys I need the business revenue--BUT please FFS, don't buy Toyota or Lexus PLEASE!
All the best Dennis

sprintguy
05-19-2017, 05:33 PM
First you do not have to replace the whole cooler to fix the sensor hole (or protrusion) you just need the front EGR housing. Next I cannot believe that the resistor even worked for it does not vary in resistance when the EGR valve is opened.. I would like to see how long that vehicle is fault free. I agree with Dennis, keep messing around with these vans and not truly fixing them, I will just wait around until the repairs that need to be made result in way too much money to be worth it, then listen to these same people tell me how much of a garbage can these vans are. When the only issue stemmed from a Engine tune that was supposed to "fix all your worries". I challenge these tuning companies ... If the result from there "fix all" tune ends up costing an engine 50k miles down the road , are they going to pay for it? The answer is in my best guess .. "not our problem" you should have read the disclaimer that the tune was for off road use only.
Guys, buyer beware, I would hate to see a good van go south due to a program. It does happen more than we all may know.
until then keep on messing with it , I need to put 5 kids through college.:cheers::cheers:

Carl

ecowhale
05-28-2017, 08:00 PM
The resistor finally failed (engine light on, OBD says EGR temp sensor). I replaced the sensor (was very hard to find the right part) and no engine light for 8k miles, but the sensor is still not installed, just resting on top of engine.

Now I have less than half the problem solved: Senor now working, but not installed.

Unfortunately contrary to your statement, the sensor hole is in the cooler which spans across the engine / long in size, so I don't plan to replace the cooler since I plan to sell the RV in mid 2018 upon buying a next gen Sprinter (I can't fit in Dodge - too short, or Ford - cabin too small, products).

ecowhale
05-31-2017, 12:15 AM
First you do not have to replace the whole cooler to fix the sensor hole (or protrusion) you just need the front EGR housing.
Carl
I stand corrected... I see the EGR housing houses the sensor and is separate from the cooler!

autostaretx
05-31-2017, 01:07 AM
Eco: while you have the new part not solidly installed, why not unplug it and *measure* its resistance at a few temperatures?

I'd suggest 32F (0C): water containing melting ice; 20C (68F) or close to it; and anything close to boiling (212F (100C)).
From those 3 temperatures we can pretty much determine the device's full curve (and won't risk damaging the sensor with a propane torch).

Then we'd all know for the future...
--dick

lindenengineering
05-31-2017, 03:56 AM
I suggest fix the bloody thing properly and forget it !
Dennis

ecowhale
06-07-2017, 03:17 AM
I suggest fix the bloody thing properly and forget it !
Dennis

Thanks, and normally that's the best option, but I plan to sell my van within a year and due to living in it full time, don't want to deal with a hotel for several days. I believe I can fix it myself, but am not sure; might end up having it towed if I try (some other cheap part might break).