BL49

Wideband Lambda Controller with Bosch CJ125 and LSU 4.9 with 0-5V output and CAN-Bus Interface

Feature list

• CAN output, compatible with AEM X-Series UEGO
• analog output for lambda 0.65 to 1.3 (0.25v to 4.8V)
• debug messages over CAN (pid, heater status, diag registers, ...)
• activatable via TTL input (INPUT 1)
• fast: 10ms refresh rate (reading the probe, calculation lambda and O2, sending CAN message and setting analog output)
• Bosch recommended heating strategy

04.01.2023 - Current status of firmware development

• analog output for lambda 0.65 to 1.3 (0.25v to 4.8V): done
• CAN output (AEM X-Series UEGO protocol): done
• debug messages over CAN: done
• Bosch recommended heating strategy: done
• PID controller for heating the probe: done
• activation per GPIO (pull IN1 to GND): done
• activation per CAN: open

29.04.2020 - Version 0.0.1 - only hardware released / no software available at the moment

Interactive BOM for easier hand-soldering you can download from the github (BL49/hardware/V0.0.1/bom)
or access online here: https://oelprinz.000webhostapp.com/BL49/V0.0.1/iBOM/ibom.html
Quick link to schematic: https://github.com/oelprinz-org/BL49/blob/master/hardware/V0.0.1/schematics.pdf

Bosch CJ125 (LQFP32 package) part numbers

Bosch part number
30615
40103
30522

Suitable Bosch lambda probes

Basically, the Bosch probes whose numbers start with 0 258 017 will fit, also Bosch 0 281 004.
Bosch numbers beginning with 0 258 007 are LSU 4.2 probes and will not fit.

Bosch number	Length overall	Comment
0 258 017 012	1060mm
0 258 017 025	1000mm	Bosch motorsport part, tested during development
0 281 004 028	540mm	common probe for diesel engines, Used during development
0 258 017 029	620mm	grey, used by BMW after 09/2006 (1178 7539124)
0 258 017 038	340mm	grey, used by BMW (11787537984)
0 258 017 092	950mm	black, used by BMW (1178 7540167)
0 258 017 126	680mm	black, used by BMW after 09/2006 (1178 7561410)
0 281 004 150	1215mm
0 281 004 184	1000mm
...

LSU4.9 probe pinout

Pin#	Color	Description	Symbol
1	red	Pump current APE	IP
2	yellow	Virtual ground IPN	VM
3	white	Heater voltage H-	Uh-
4	grey	Heater voltaget H+	Uh+
5	green	Trim Resistor RT	IA
6	black	Nernst voltage UN	RE

Hardware

MCU Fuses

AEM X-Series CAN layout

Assembled Prototype

PCB Layout