Need IAT sensor range specs
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Super Member
Joined: Feb 2013
Posts: 659
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From: SE MI
2005 Mercedes E55 AMG
Need IAT sensor range specs
Does anyone have the ability to get me the operating range for the stock IAT sensor? Voltage and resistance
Mercedes: 651 153 0028
Standard: AX129
MOPAR: 5174042AB
I've called 6 MB dealerships and no one wants to help
Mercedes: 651 153 0028
Standard: AX129
MOPAR: 5174042AB
I've called 6 MB dealerships and no one wants to help
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From: Orbiting the planet
This place is a joke.
I'll see what I can find for you. BTW I've found a way to mount the stock sensor in the surge tank runner using a brass fitting and circlip. Can't post pics from my phone Ill for it later when I'm home.
Thread Starter
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Joined: Feb 2013
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From: SE MI
2005 Mercedes E55 AMG
To give a little more clarity on my request, I want to use one sensor for both my datalogging and my ecu input. I have the Zeitronix sensor and I want to see if this operates within the same range as the stocker. Not likely, but it's worth a shot. If I have to run two, I would prefer to move the stock sensor further downstream so those pictures would be nice
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From: West
2005 E55 Wagon
Yes, please post pics! Sorry for the stupid question, but what is the benefit of moving the IAT sensor for its OEM location?
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Joined: Feb 2013
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From: SE MI
2005 Mercedes E55 AMG
For my application, the sensor isn't realizing the cooling effects of my water injection well enough because I flow too much air. With the sensor closer to the engine, it gives the water a chance to mix with the air more completely.
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From: Orbiting the planet
This place is a joke.
Here's what I found for you.
Its an NTC resistor. The resistance drops with increasing temperature.
ECU sends 5v signal and monitors the return voltage on the other wire.
20C/68F = 2.7v
40C/104F = 1.8v
60C/140F = 1.1v
Polarity of the sensor itself is not important/random.
Resistance of the sensor:
68F = 5800-6300 Ω
86F = 3700-4110 Ω
104F = 2500-2700 Ω
122F = 1700-1850 Ω
140F = 1100-1350 Ω
158F = 800-920 Ω
176F = 550-700 Ω
Its an NTC resistor. The resistance drops with increasing temperature.
ECU sends 5v signal and monitors the return voltage on the other wire.
20C/68F = 2.7v
40C/104F = 1.8v
60C/140F = 1.1v
Polarity of the sensor itself is not important/random.
Resistance of the sensor:
68F = 5800-6300 Ω
86F = 3700-4110 Ω
104F = 2500-2700 Ω
122F = 1700-1850 Ω
140F = 1100-1350 Ω
158F = 800-920 Ω
176F = 550-700 Ω
Last edited by E55Greasemonkey; Jun 12, 2014 at 06:45 PM.
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This place is a joke.
This is my second IAT location. I am still testing so I don't have any announcements yet, but I believe the stock IAT location is getting wet when spraying meth and causing a large temperature drop after letting off the gas, as the liquid evaporates off the sensor. Likewise during boost/spray, the sensor is being coated with the water/meth and reading the temperature of the liquid, not the actual air temperature. I wanted to verify the actual air charge temp by eliminating this possibility. Hopefully moving it farther away directly out of the spray will be more accurate. I still have the factory IAT installed to easily switch back to to prove my theory.
Last edited by E55Greasemonkey; Jun 12, 2014 at 06:47 PM.
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From: Florida
A Merc
I connected my zt2 to the iat line and I was getting voltage, I contacted dashdaq and they told me they needed the voltage to degrees to make a formula for it, this seems like what they need
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Thread Starter
Super Member
Joined: Feb 2013
Posts: 659
Likes: 25
From: SE MI
2005 Mercedes E55 AMG
Here's what I found for you.
Its an NTC resistor. The resistance drops with increasing temperature.
ECU sends 5v signal and monitors the return voltage on the other wire.
20C/68F = 2.7v
40C/104F = 1.8v
60C/140F = 1.1v
Polarity of the sensor itself is not important/random.
Resistance of the sensor:
68F = 5800-6300 Ω
86F = 3700-4110 Ω
104F = 2500-2700 Ω
122F = 1700-1850 Ω
140F = 1100-1350 Ω
158F = 800-920 Ω
176F = 550-700 Ω
Its an NTC resistor. The resistance drops with increasing temperature.
ECU sends 5v signal and monitors the return voltage on the other wire.
20C/68F = 2.7v
40C/104F = 1.8v
60C/140F = 1.1v
Polarity of the sensor itself is not important/random.
Resistance of the sensor:
68F = 5800-6300 Ω
86F = 3700-4110 Ω
104F = 2500-2700 Ω
122F = 1700-1850 Ω
140F = 1100-1350 Ω
158F = 800-920 Ω
176F = 550-700 Ω
This is my second IAT location. I am still testing so I don't have any announcements yet, but I believe the stock IAT location is getting wet when spraying meth and causing a large temperature drop after letting off the gas, as the liquid evaporates off the sensor. Likewise during boost/spray, the sensor is being coated with the water/meth and reading the temperature of the liquid, not the actual air temperature. I wanted to verify the actual air charge temp by eliminating this possibility. Hopefully moving it farther away directly out of the spray will be more accurate. I still have the factory IAT installed to easily switch back to to prove my theory.
I had the same suspicions with regard to the water to close to the IAT. Then again, you know this because we've been texting (just realized it was the same screen name). I'll be installing all of my datalogging equipment this weekend, hope to get you an update
I have the resistance tables for the sensor provided with the ZT-2. This was quite a pain in the *** to get out of Zeitronix because it doesn't sound like they want it shared with the public. I can respect that but since I bought the product, I see nothing wrong with getting all of the needed specs so anyone with a ZT-2 feel free to PM me for the table if you need it. What I CAN say is now that GreaseMonkey has provided the resistance values, I see that these two sensors would not be interchangeable. The aftermarket sensor has FAR more resolution so its scale is greater.
Last edited by rockthemullet; Jun 13, 2014 at 02:39 PM.
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From: Florida
A Merc
I mean I hardwired into the iat sensor wire from the ecu, on one of my user inputs for the zt2 and when I was talking with dashdaq they said they needed the values for example what 1 volt is equal to in degrees so they could do the math equation via dashdaq via their SW and we could use a signal via zt2 instead of obd
Thread Starter
Super Member
Joined: Feb 2013
Posts: 659
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From: SE MI
2005 Mercedes E55 AMG
I mean I hardwired into the iat sensor wire from the ecu, on one of my user inputs for the zt2 and when I was talking with dashdaq they said they needed the values for example what 1 volt is equal to in degrees so they could do the math equation via dashdaq via their SW and we could use a signal via zt2 instead of obd
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From: Houston
2003 W211 E55, 2003 W220 S600
I have a GM temp probe on one surge tank and I have a gauge display in the cabin. Simple and easy.
Some guys also relocated the ambient temp display on the surge tank and get the IAT reading on the dash.
Some guys also relocated the ambient temp display on the surge tank and get the IAT reading on the dash.
Last edited by shardul; Jun 13, 2014 at 05:07 PM.
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From: Orbiting the planet
This place is a joke.
I think the ambient temp sensor reads too slow for this application. But who knows until you try it. Bad weather here (heavy rains) has slowed down my testing with the relocated IAT sensor. It appears to be working good so far.
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05 E55 AMG, E320 CDI, Turbo E46 M3,IS300 2JZGTE,VQ35 Turbo Maxima, Mercedes 300D
Best thing I've found if you are looking for values is to use OBD 2 readings, connect volt meter and if possible use a power supply to vary input voltage from 5V down to 0V. You can then get a good correlation between the two.
If you have none of these then use input from Dashdaq/ZT to log a voltage reading and temp reading via OBD from cold to warm ... You can extrapolate the curve on each side.
If you have none of these then use input from Dashdaq/ZT to log a voltage reading and temp reading via OBD from cold to warm ... You can extrapolate the curve on each side.
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From: Florida
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No tried the using the obd and using voltage, it doesn't work, user input is very fast, it might go up or down but obd is the same
With what greasemonkey has posted I'll contact dashdaq and see of they can come up with an equation for the rescaling calculator
With what greasemonkey has posted I'll contact dashdaq and see of they can come up with an equation for the rescaling calculator
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From: South Africa
2018 E63s AMG (Current) 2011 CL63 AMG (Sold) 2005 CLS55 AMG (Sold) 2004 C32 AMG (Sold)
Wish this thread kept going, some interesting stuff here. Was hoping to see the results by greasemonkey after the relocation of the iat vs the readings in the stock location with spraying meth.
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2005 e55 AMG
In my tune temperature correction has been eliminated . Only way to get away with that is to know exactly what your IAT's are under all conditions or you can damage the engine.
Mine was pulling timing way to much for really no reason so it is set up like this now and will hold 21-22 degrees timing nice and solid now.
Nitrous also wrecked havoc on the IAT reading's just like Meth does in some circumstance's.
Mine was pulling timing way to much for really no reason so it is set up like this now and will hold 21-22 degrees timing nice and solid now.
Nitrous also wrecked havoc on the IAT reading's just like Meth does in some circumstance's.
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Joined: Jan 2007
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From: South Africa
2018 E63s AMG (Current) 2011 CL63 AMG (Sold) 2005 CLS55 AMG (Sold) 2004 C32 AMG (Sold)
In my tune temperature correction has been eliminated . Only way to get away with that is to know exactly what your IAT's are under all conditions or you can damage the engine.
Mine was pulling timing way to much for really no reason so it is set up like this now and will hold 21-22 degrees timing nice and solid now.
Nitrous also wrecked havoc on the IAT reading's just like Meth does in some circumstance's.
Mine was pulling timing way to much for really no reason so it is set up like this now and will hold 21-22 degrees timing nice and solid now.
Nitrous also wrecked havoc on the IAT reading's just like Meth does in some circumstance's.
Super Member
Joined: Jan 2007
Posts: 979
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From: South Africa
2018 E63s AMG (Current) 2011 CL63 AMG (Sold) 2005 CLS55 AMG (Sold) 2004 C32 AMG (Sold)
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From: SoCal
2006 E55, Various other German and ‘Murican
This is my second IAT location. I am still testing so I don't have any announcements yet, but I believe the stock IAT location is getting wet when spraying meth and causing a large temperature drop after letting off the gas, as the liquid evaporates off the sensor. Likewise during boost/spray, the sensor is being coated with the water/meth and reading the temperature of the liquid, not the actual air temperature. I wanted to verify the actual air charge temp by eliminating this possibility. Hopefully moving it farther away directly out of the spray will be more accurate. I still have the factory IAT installed to easily switch back to to prove my theory.
There is no reason I see why this alone would not at least modestly work, to avoid the spray cooling problem. A second sensor is needed for logging and other purposes anyway really.
Only other improvement would be to find a sensor that can output same voltage ratios for the ECU to see. Maybe it would be quicker.
But getting more accurate readings on stock temp probe in ECU expected ranges would be best.
