MembersPage/Norbitron/VemsEcuNarrowbandOxygenOutput (2017-07-31 11:02:31)

V3 to send a linear wideband output signal to a 3rd party device

Page title is misleading: originally it was narrowband sensor emulation, but wideband output is also possible of course


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V3 with lambda output was used in Fefe's Lada Samara which historically had 3 ECU:

Fefe's HW had a 5V output and a voltage divider of 5.7: 1k/(1k+4.7k)

It was a bit special, we need to check how it can be configured currently (possibly adding some config options is justified ?).

It seems to be still active if NBO2_OUT is defined in my_make..., as PWM on S259_OUT2 output. This pin is inside VEMS v3, on the s259 chip.


An OEM ECU in this case. This can already be done with a Round

display, but as discussed, this would be possible to do with a

custom (or new standard with some new options) firmware on the V3 as well. If possible we would like to get

the same signal that the round can send on the analog output when

vout_conf=5, which is a wideband high resolution linear output

(0..5V) There is really no need for any configuration options for

this, everything can be hardcoded if such feature is not wanted in the main-line firmware.


This v3 ECU (serialnr... ) has two EGT sensors however egt2 reads 30C higher

even when testing outside of the car. Giving a constant heat for the thermocouple then switching it from egt1 to egt2 in

the harness, gives an instant increase of the reading by 30C.

However the difference is not linear, the issue manifests over around 300degC.

The given calibration is for EGT1, but egt2 should be very close (definitely much closer than 30C).

Can you check the sensor cable ground connection ?

Possible options:

hint: Connect the same calibrator or K-thermocouple to both inputs simultaneously, and take note of some actual readings to see the calibration curve.