Bias resistor consistency

[Marek]

I am about to install a few more temperature sensors. Not all of them are by the same maker and not all of the ones that are already installed are consistent with each other.

Since I suspect that all of them are simple NTC type thermistors, would a sensible policy be to adjust all of the bias resistors to equal each individual sensor at ambient conditions during the a day when the car has not been driven?

I notice that the sensor calibrations (usually locked) have various 3point calibrations. Are all of these settable individually and is it these 3points that are stored for each thermistor type?

I notice that in MS3, I have the choice of several calibrations for CLT and MAT, but for generic sensors, a non linear sensor can only have same as CLT, MAT, GM calibration or same as MAF - this seems quite restrictive.

Finally, as I don't use MAF, I did think to install a custom.inc file with a custom calibration for all 1024 values and have a coolant sensor in generic sensors set to "same as MAF" but this didn't give the expected value. Ought this not to be a way to always be able to get one custom calibrated sensor into generic sensors any time MAF is not in use?

kind regards
Marek

[jsmcortina]

Upgrade to the current firmware, you get to choose "custom#1" sensor calibration instead of MAF.

James

[Zaphod]

I haven't found a hint in the manuals on how to set up such a custom.inc for a sensor - can you give me a hint please?
(I'd like to use a generic VDO oil temp sensor)

Thanks
Sven

[jsmcortina]

That's more of a TunerStudio question as that software parses your supplied file and then sends it on to the firmware.

James

[Zaphod]

That's more of a TunerStudio question as that software parses your supplied file and then sends it on to the firmware.

James

I found out what the inc-file has to look like and how to input it in the calibrations menu - but what does the MS expect me to have in the file

volts vs. temp ?
resistance vs. temp?

I am sorry but I am not such an electronics guy - how do I calculate the correct value with a 2490 ohm bias resistor to +5v in place?
(I guess you have to calculate, because if I try to load the custom.inc in the calibrations menu, there is no way to tell the MS the value of the bias resistor anymore (as is, when you put in a 3-way calibration or other known sensor))

Thanks for the help!