Analog Oiltemp Sensor - no curvation

[6nfanatic]

Hello,

i want to connect two Bosch kombisensors (with pressure and temp in one). Pressure is easy, you got all the data you need. Problem is the temp.

Since you need to use a Pullup resistor, the temp / voltage curve is not linear. Thats a problem since in the analog inputs on teh kpro i can only add a linear with two values. How can i build that to make my oiltemps reading accurate?

Thanks

[Hondata]

The conversion needs to use the Steinhart-Hart equation.

http://www.hondata.com/help/kmanager/in ... rature.htm

There are two supported Bosch sensors; not sure what you have.

[6nfanatic]

Hi,
thanks for the answer.
The sensor is that one:

bosch 0261230340

I can do the Steinhart equation but i do need 3 points to set. In the krpo analog under custom, i can only set 2 values.

Also the curvation changes when you have a different resistor. In the Hondata manual it says 1.1kohm is recommended while bosch says a 4.7kohm is recommended.
Usually thats not a problem, i was using a ECUMASTER Black before and you can plot the curvation using the wizard with the different resistors.

But yeah, unsure now of how i should use the values.

[Hondata]

There is no way to enter custom points for the curve. We support the two Bosch sensors but not the combined sensor you mention.

I would test with it set to each of the supported sensors using a 1.5k pull up and see if the conversion is the same.

[6nfanatic]

Hey, i looked the Bosch CLT and the one i have up. The resistant is pretty close. I guess it will work. But how can i verify it? It would be literally quite bad if the ECU thinks the oil is 130°C while in reality its more like 150°C.

Id like to see more sensors in the kmanager. The Bosch 0261230340 is pretty much the one people are buying nowadays since its pressure and temp in one. Its the same sensor thats used in the Porsche 918 Spyder so i guess its a good one :)
You can consider it.

[Hondata]

The 0280130026 0280130039 0261230340 have the same resistance according to the datasheets. Nominally 2.5k @ 20C, but the full curves are published for comparison.

If you are concerned about accuracy then I would test in ice water and very hot water with another thermometer to verify the temperature.

[6nfanatic]

okay then i should be good to go.
Can you tell me which pullup i should use? 1,5k ohm as said in the hondata manual or 4,7k ohm as said at bosch?

Thanks for clarification

[Hondata]

1.5k if you want it to work.

[6nfanatic]

That was a very helpful thread.

Thank you very much. Glad i bought the kpro :)