This development board is PnP for Mercedes with the 128 Pin ECU (could be used on M104, M111, M112 and M113 engines; late 90s-early 2000s. confirm your ECU _harness_)
If you want to control the clutch on a Mercedes supercharger, some hardware modifications are required. The following modifications will result in pin F21 being able to control the supercharger clutch:
By design Rev. A and Rev. B boards are designed to drive the VVT coil. On Rev. C hardware E1, E2, E3 and E4 can all be used as solenoid control. They have the internal diodes needed for protection.
Using the Interactive pinout, Test Points are documented that are connected from the Car connector to the PCB. These can be connected with wires to the Test Points that are available in TunerStudio.
E17 is Test Point P17 (In some variants this is oil level).
In case we would like to use this as an oil pressure sensor, in Tuner Studio: Sensors > Oil Pressure > Oil Pressure ADC input drop down would display a list where we can see P30_IN_AUX4. By selecting this input, the user needs to connect a wire from P17 to P30.
The end user should keep track of mods, since there is no way for us to do this. Dedicated connections are available in Tuner Studio with Car connecter Pin cod in the name.
todo: add a picture with board/TunerStudio config.
### Extension Pads
| Pin | Type | Comments | Hardware revision |
|---|---|---|---|
||**Outputs**|||
| P18 | Low side | 1.5 A | C |
| P19 | Low side | 0.5 A | B, C |
| P33 | Bridge driver B | 3 A peak | A, B, C |
| P34 | Low side | 0.5 A | A, B, C |
| P35 | Low side | 0.5 A | A, B, C |
| | **Inputs** | | |
| P30 | Analog pull up | | A, B, C |
| P31 | Analog pull down | | A, B, C |
| P32 | Analog pull down | | A, B, C |
| P36 | Analog pull down | | B, C |
| P40 | Analog pull up | | B, C |
| P41 | Analog pull up | | B, C |
| | **MCU** | | |
| J1 | SPI, UART/GPIO | See schematic for details | A,B,C |
Since a narrow band lambda (O2 sensor) was used in the original ECU, Hellen includes an onboard wideband controller. A harness is needed to connect the lambda sensor, these lines are not possible to wire in to the car connector.
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 to simplify starter wiring and add a start button
* And obviously your engine harness should use <ahref="Images/mercedes-128.png">this ME 2.0 style of plug</a> not <ahref="Images/mercedes-134.png">this 134 pin style of plug</a>.
As of April 2022 we know nothing about m111 automatic transmission control. All successful swaps so far were using manual gearboxes. 722.6 automatic transmission
* better provisions for high-current control of supercharger [clutch solenoid on M111 Q6 R80](https://github.com/rusefi/hellen128merc-issues/issues/10)
