There are many similar types. Often the difference is just the length of the cable.

Here is a link about the pinout of the WBO2 sensor with the little connector. Theese sensors used by MOTEC.

Bosch LSU4.7 / 4.2 Technical specification


LSU4.9 - with smaller connector

This (currently not used by us) sensor has smaller (but same "U" shape) connector.

Measurements seem to show that it requires

If it's used, ever, it requires special care during configuration (since connector is different, this might not be that big problem).

Bosch LSU 4.9 vs. 4.2 (fex. '6066' sensor) indeed differs somewhat technically.

  • Exhaust gas temp 930 C vs. 850 C deg (allowable continuous ? - datasheet does not give a clue).
  • Heater supply / power; 7.5 V / 7.5 W vs. 9 V / 10 W
  • Lambda measuring range from 0,65 vs. 0,70

Mini-LSU 4.9 sensor seems to be (temp etc. vise) similar to LSU 4.2.

Bosch has AWS_LSU 4.9 unit to connect/interface two Mini-LSU 4.9 sensors to CAN.

The connector housing itself is a problem. Only possible to buy from VW (part dealers). The MPT receptracles and small rubber seals shouldn't be a problem.


google search (no success; maybe someone who speaks Japanese ?):


PINOUT: This link should give L1H1 pinout: http://techedge.com.au/vehicle/wbo2/wbsumi.htm

http://www.vems.hu/files/MembersPage/LevaiJozsef/ has drawing for the known Bosch:


5,1,6,2 are respectively pump-, nernst, pump+, rcal

(and 3,4 are heater).

The not-so-well-known NTK WBO2 sensor connection:


But no signal names, only pins of an unknown (VAG, audi?) ECU. Might give hint for pump- and nernst. Rcal is very different from Bosch, maybe inverted pump current and rcal ?

NTK sensor with small connector working :

In v3.x with pump PI values (instead of orig 0x15, 0x37 that we traditionally use for LSU4) 0x0F, 0x17 reached regulation (This is not tuned in exhaust, just with 0x15, 0x37 pump fluctuated wildly). D=0 as always.

Note that wbo2_calibration=0xB1 was good for NTK_RCAL=287 Ohm. TODO: check if this is close to bosch LSU4 or very different.