# External WBO

* External controller with analog output, like then AEM 30-4110 and similar products.
* External controller with CAN interface, like the AEM X-Series wideband controller/gauge.


# rusEFI Wide band oxygen

rusEFI has two probably working implementations for Bosch wideband oxygen control:

* We have cj125 integration 
* We like https://github.com/mck1117/wideband even more. See https://rusefi.com/forum/viewtopic.php?f=4&t=1856

# rusEFI wideband module

rusEFI own wideband module requires one time initial programming. Self contained version of the board relies on custom USB header while module integrated into Hellen requires usage of ST-Link programmer hardware via TC2030 or breakout SWD pins.

initial programming binary at https://github.com/mck1117/wideband/tree/master/for_rusefi

At the moment only known to work using stm32cube software not ST Link utility (weird). In case of Hellen 5v via USB is required.

TODO: document it better


# cj125 troubleshooting



We have a few rusEFI console commands relevant for cj125

``cj125_info``

``cj125_restart``

``cj125_calibrate``



![x](Overview/wbo/cj125_heating_4_9.png)


AndreiKA says Prometheus works

Matthew says 0.3 SOIC-24 boards works

Wideband controller based on Bosch CJ125 chip

green is vUr, temperature feedback

red is duty cycle

yellow is vUa, the lambda current measurement

white is converted AFR

fully operating in <30 seconds

in to closed loop in ~18 seconds

P=30

I=5

D=0.3

though you could probably use D=0 since the system is already damped so hard

50Hz


[Older SOIC-24 board - double sided assembly](https://github.com/rusefi/hw_modular/tree/master/cj125_Module)

[Newer LQFP-32 board - single side assembly](https://github.com/rusefi/rusefi/tree/master/hardware/CJ125_board)


# Naming Convention

IP=Pump Current

VS/IP=VM=common virtual ground for VS and IP

R Trim=Calibration resistor

H+ Constant +12v

H- Heater control, low-side

UN = Vs = sensor voltage output

4.9 pinout courtesy of https://www.wbo2.com/cable/lsuconns.htm

![x](FAQ/LSU-4-9-17025hcon.gif)



![x](FAQ/LSU_42_LSU_49_Plug_Comparsion.jpg)

With SOIC-24 rusEFI module W1=W10=0R means LSU 4.2

With SOIC-24 rusEFI module W1=W10=Do not populate means LSU 4.9

Q: Any troubleshooting hints when things do not work?

A: VM wire between CJ125 and sensor is virtual ground, should measure 2.5v when sensor is connected and when sensor is disconnected.