Wideband probe Bosch LSU ADV is a next-in-line product after the popular LSU 4.9. LSU ADV is used in modern BMW turbo engines as the primary (pre-cat) probes.
The most significant, compared to LSU 4.9:
- more extensive temperature range. The allowed range of the exhaust gases stays the same: 930 oC (1030 oC for a short period), but the temperature range of the body of the probe is increased from 600 oC till 820 oC;
- “lights off” stage is shortened. ADV probe is entirely ready to work already 5 seconds after starting of the heating;
- the robustness of the probe is improved. Here though, I am a skeptic – the ceramic plate has got even thinner than it was for LSU 4.9. The widened temperature range of the whole body of the probe may be the basis of such a statement.
LSU ADV is specially intended for vehicles with turbo engines, which are equipped with Start/Stop system, and which should fit in the EU6 exhaust norms. That’s why the high allowed temperatures, the requirement for readiness for work.
LSU ADV doesn’t have the trim resistor in the body of the plug anymore. The probe trimming operation is done for the sensor element itself. Accordingly, the probe has only five wires.
Also, the Lambda/Ip map of the probe has changed. But, and this is more significant – in the datasheet, the curve which describes the dependence of the data of the probe from the pressure of the exhaust gasses. For LSU 4.9 probes, this error was smaller and it could be ignored.
From specific changes – the allowed load on the Nernst cell is reduced four times. So, without illusion – these probes are/will be more sensitive to any kind of contamination (with oil, fuel products).
Algorithms of the probe management are not changed, Bosch uses the standard connection with
Uo = 1.50 V by Lambda = 1.00 in their DME.
Here, the table, which describes U vs. Lambda:
In the data range, in which Lambda is different from 1.00, the error created by the pressure of the exhaust gasses should be taken into account, but the table can be used for an approximate result.