Hellen 128 Mercedes

This development board is PnP for Mercedes with the 128 Pin ECU (could be used on M104, M111, M112 and M113 engine; late 90s-early 2000s. confirm your ECU harness)

Download release firmware Snapshot firmware bundle

Pinout & Google Sheet & Another Google Sheet

Issue Tracker

[Schematics rev a]](Hardware/Hellen/hellen128mercedes-a-schematic.pdf)[iBom rev a

[Schematics rev b]](Hardware/Hellen/hellen128mercedes-b-schematic.pdf)[iBom rev b

Hardware features

• ME 2.0 pinout
• supports both smart and dumb coils
• ?

4 cylinder configuration

With R80 on the back side

test points

Rev B naked board

Rev A naked board

Extension Pads (rev. a)

Pin	Type	Comments
	Outputs
P33	Bridge driver B	3 A peak
P34	Low side	0.5 A
P35	Low side	0.5 A
	Inputs
P30	Analog pull up
P31	Analog pull down
P32	Analog pull down
	MCU
J1	SPI, UART/GPIO	See schematic for details
	WBO1
J9	XH-8 WBO1 connector
P19	GND
P21	H-
P22	R Trim
P23	Ip
P24	Vs/Ip
P25	Vs
J7	SWD
	WBO2
J18	XH-8 WBO2 connector
P18	GND
P20	H-
P26	R Trim
P27	Ip
P28	Vs/Ip
P29	Vs
J19	SWD

Extension Pads (rev. b)

Pin	Type	Comments
	Outputs
P19	Low side	0.5 A
P33	Bridge driver B	3 A peak
P34	Low side	0.5 A
P35	Low side	0.5 A
	Inputs
P30	Analog pull up
P31	Analog pull down
P32	Analog pull down
P36	Analog pull down
P40	Analog pull up
P41	Analog pull up
	MCU
J1	SPI, UART/GPIO	See schematic for details
	WBO1
J9	XH-8 WBO1 connector
	WBO2
J18	XH-8 WBO2 connector

Ignition jumpers (rev. a, rev. b)

Vehicle	F2	F3	F4	F5	F6	F7	F8	F9	F10	F11	F12	F13	F14	F15	F16	F17
Connctor pin (NOT jumper designator!!!)	F4	F5	F6	F7	F9	F10	F11	F12	F13	F14	F16	F17	F18	F19	F20	F21
IGNx signal	IGN5	IGN5	IGN3	IGN3	IGN7	IGN7	IGN8	IGN8	IGN4	IGN4	IGN2	IGN6	IGN6	IGN2	IGN1	IGN1
4 cyl 2 coil	🟡	🟡	🟡	🟡	🟡	🟡	🟡	🟡	✔️	🟡	🟡	🟡	🟡	🟡	✔️	🟡
Other model	?	?	?	?	?	?	?	?	?	?	?	?	?	?	?	?

🟡 - it doesn't matter, the specified pin is not connected

Coil type	R43	R59	R67	R60	R79	R66	R74	R62	R76	R63	R77	R64	R78	R65	R73	R61
Dumb	❌	✔️	❌	✔️	❌	✔️	❌	✔️	❌	✔️	❌	✔️	❌	✔️	❌	✔️
Smart	✔️	❌	✔️	❌	✔️	❌	✔️	❌	✔️	❌	✔️	❌	✔️	❌	✔️	❌

4 cylinder application

• uses inj 5-6-7-8 for INJ
• two IGBT: Q1 & Q3
• one MOSFET soldered instead of IBGT for clutch solenoid
• INJ3 with fly-back for boost control solenoid

M104

• three IGBT: Q1, Q3 & Q5

Vault-Of-Mercedes-OEM

Mercedes-C230-and-SLK230

FAQ

Would this work on my all original Mercedes?

Hellen 128 was originally designed for M111 swaps into W201. Depending on the year some W202, R170 and other models could be driven with different amount of supporting mods:

• Somewhere around 99 Mercedes has transitioned from just plain wires on C40 and D3 to CAN-bus starter security. For those later models one would have simplify starter wiring and add a start button

• And obviously your engine harness should use this ME 2.0 style of plug not this 134 pin style of plug.

Changelog

rev C

• wastegate diode

rev B Aug 27, 2021

• better provisions for high-current control of supercharger clutch solenoid on M111 Q6 R80
• ignition fuse changed from 36915000000 5A to 2010-T10A0V2T11192AM5G 10A. 0697H9100-02 could be use for refitting of rev A

rev A June 10, 2021

• good to drive, great success!

Spare Parts

ISL9V3040S3S is the large IGBT driver (same thing as ISL9V3040S3ST)

Smaller NGD8201AN or ISL9V3040D3ST could probably be used as well.