Bosch Dual Sensor 0 261 230 340 temperature issue.

Hello there!

I’m having some issues with Bosch “0 261 230 340” Dual sensor installation and temperature information that I get from it.

Right now, I have a “Chinese” Defi Dash with oil pressure and temperature data (plus other data), but I’m installing a Ecumaster ADU dash and I wanted to use the Bosch Dual sensor to take this data.

After all the wiring and installation (with a 1K pull up resistor for temperature sensor), I have the following situation:

Oil pressure: Data between Defi and Busch sensor (ADU) are the same à OK (I guess)

Oil temperature: I get a weird difference between the Defi and ADU datas.

When starting the car for the first time temperatures are the same between them.As the cars warms up, the Defi starts to get higher temperature than the ADU, up to 10-15ºC. For example, Defi 60ºC and ADU 50ºC, or 95ºC vs 80ºCIf I turn off the car, as the cars cools down, the temperatures equalize. Even they both can show 50ºC when during the warm-up they had a difference of 10º (60ºC Defi vs 50ºC ADU) I think that if the problem were a wiring/calibration table issue I should always have the same problem, but it’s like the Bosch sensor takes longer to “warm up” and longer to ”cool down”.

The point is that, since is my very first time doing this, I cannot say directly that the problem is the “Chinese” Defi. I’m not sure which one is getting correct data.

Additional information:

When coolant temperature is about 89-95ºC, Defi shows oil temperature about 95ºC-97ºC, ADU shows max 80ºC. (I’m worried since it seems that Defi temperature have more sense?) Both sensors are mounted in an Oil Sandwich (around 4cm between them).Bosch is mounted with an adaptor from M10 to 1/8NTP. Could it be that the oil flow is not reaching the Bosch sensor correctly and that is why it takes more time to warm up and also to cool down? Don’t know if this has sense since oil pressure seems to be OK (at least same between Defi and ADU).

Any ideas about what can I do to tests things or what could be the problem?

Thank you!