MoTeC Global Forum

HI, we get a racing car with the motec system (ECU M400) from US, this car had a Bosch LSU 4.0 wide band lambda sensor, we decide change this sensor, and when i see the calibration number put in the system was 1020, i didn't see this number on the outside of the old sensor. well on the new sensor i dint see a number like a calibration number, for this i use the air calibration option, i wait 10 minutes and then, the number was between 1145 and 1157, what i do wrong ? or what number i can put ?

note i put the sensor in the air when i calibrate.


and another thing,for a test, i put the old sensor in the air and see that the calibration number that this do was between 1345-1370

The numbers you have mentioned sound about right. The sensor calibration will change as it ages so using the number written on the sensor, only applicable if you bought it from MoTeC, will be OK when the sensor is new, but I would recommend checking the calibration after a period of running.
Remember this must be performed with the sensor in free air in an open space not in the garage/dyno where fumes can accumulate and affect the reading.

ok thank you, for this reason is that the old sensor in the air calibration was in 1345 and in the system was 1020.

but what interests me is the new sensor, i fail to identify the number of calibration on the sensor,I compare the numbers in the body of the old sensor with the number that was in the system and any combinations, was closest on the sensor body a circle with the number 020 and the system was 1020, but the new sensor also have the circle with the same number 020 and I have understood that the number of calibration varies with each sensor, so choose to air calibration, as explained above, the number as it leveled off after ten minutes was between 1145 and 1157, at the end i put the system in 1148. say is right then?

I've found a bug with the air calibration with the latest version.

If you come from a Fuel or Ign table to the air calibration setting the value displayed will be from the last cursor position from that table with the decimal place different. I haven't tried it from other tables but I'm not sure i trust it with the latest version.
I did mention this to motec but have not had a response yet.

whrdnsx wrote:I've found a bug with the air calibration with the latest version.

If you come from a Fuel or Ign table to the air calibration setting the value displayed will be from the last cursor position from that table with the decimal place different. I haven't tried it from other tables but I'm not sure i trust it with the latest version.
I did mention this to motec but have not had a response yet.

Nevermind, found the problem.

Bosch sensors are not delivered ex factory with written calibration data on the bodies. The 020 in a circle is irrelevant, it has no bearing on the sensor calibration. The Bosch sensors have a laser-trimmed resistor in the plug which is how some systems evaluate the calibration. We read this value and inscribe the measured value on the body as a service for users who buy the sensors from us.

As these sensors age this value changes, thus the need for regular free-air calibration of the sensor.

Also please note that if you change the sensor type with an M800 you need to change the setting in ECU manager, as each sensor has slightly different behaviour and running a sensor with the wrong defined type may result in sensor failure.

I have acquired a box of used NASCAR LSU 4.9 sensors.

Is there a way of converting the Rcal(measured) value to the M800 calibration number?

Hi,

I would do free air calibrations on the sensors before using them, especially if they have been used since the Rcal number was measured.