Island emergency power generator with a 1.7L naturally aspirated diesel engine from a VW Lupo

Hello everyone,

I'm reaching out to you because I believe that, as professionals, you might be able to help me best with this.

I built a backup generator/mini CHP system using a 1.7L SDI engine. The engine is mounted on a frame, and the engine control is managed by the original Bosch EDC15 system. A generator is connected to the engine's flywheel via a flexible coupling, and the accelerator pedal is simulated by a small PLC (Siemens Logo) to regulate the speed. So far, everything is working as it should.

Now, I wanted to buy an ATS (Automatic Transmission System) that would control the engine starting process.
"Strictly speaking, this part:"
https://www.smartgen-america.com/catalog/products/electric-generator-controllers/hgm61xx-series/smartgen-hgm6120nc-generator-controller-amf-one-mains-one-gen-system-rs485/

This device initiates the startup process and, in addition to monitoring the coolant temperature, also monitors oil pressure, speed, etc.

Unfortunately, I would have to install additional sensors in addition to the ones already providing data to the EDC15, for this control unit. I would prefer to avoid this by using the CAN bus version of this generator control.
https://www.smartgen-america.com/catalog/products/electric-generator-controllers/hgm61xx-series/smartgen-hgm6120can-generator-controller-amf-one-mains-one-gen-system-canbus-interface/

This can directly access all the required sensor values from the CAN bus.

Unfortunately, I can hardly find any information about whether this control unit is compatible with the VW protocol. As far as I know, the diagnosis for the first generation Lupos was initially performed exclusively via the K-line, and later also via the Motor-CAN bus.

My engine already has a Motorcan interface, and the Smart-Gen control unit can read CAN bus data from the J1939 protocol, which is apparently used in construction equipment, etc. Can my Motorcan device, which is compatible with EDC15, also support this protocol?

Thank you in advance.
Best regards, Pierre.

Hello,

No J1939 and no specific VW transport protocol. You can find the sensor data in the data bytes of the corresponding CAN IDs on the CAN bus (motor CAN).

Best regards, Rainer.

Unfortunately, you cannot use the CAN variant of the ATS because the J1939 protocol cannot be used in the passenger car sector.

One option would be to use a gateway that converts signals from CAN 2.0 to J1939. Since you only need the engine temperature, oil pressure and level, and the RPM signal, a gateway is somewhat oversized.

Especially since you also need to connect the signals to the CAN bus, as the manual states that it is only intended for engine control.

Hello.

Can't you use the UPS (Uninterruptible Power Supply) for an automatic startup?

A 230V relay (there are also more energy-efficient electronic solutions) disconnects from the power supply when the power is interrupted, and signals the PLC (is it powered by 12V?) that the power is out.

The PLC then starts the generator by activating another relay connected to the starter. And a transfer relay switches the power supply of the devices from the mains to your generator.

Best regards, Rainer.

Hello you two,

Thank you for your responses; I was almost certain it had something to do with the J1939 protocol.

@Rainer, my plan now is also to do everything via PLC, since it already simulates the accelerator pedal, including the startup process and network switching.

I would visualize all the data on a Siemens HMI display, as I no longer need a speedometer. I could even tap into and display all relevant parameters such as oil pressure sensor, RPM signal, coolant temperature, generator signal, glow plug timing signal, engine check light, etc. This can be done in a fairly traditional way without a bus system (at least, that's what the pin configuration of my speedometer suggests).

As a data enthusiast, if necessary, I could even build an Arduino that reads parameters like engine load, intake air temperature, injection angle, etc. via the K-line and transmits the values via Ethernet to the PLC for visualization on the HMI.

Sure, go ahead and ask your question.

The CAN high and CAN low signals from the engine control unit are transmitted via the gray connector at the central electronics module (ZE) to the speedometer (green connector) on pins 27 and 28.
The CAN high and CAN low signals (green connector, pins 19 & 20) from the speedometer connect to the OBD connector.
In addition, pin 27 on the instrument cluster (blue connector) connects to the OBD connector via the K-line.

Now I wanted to ask if I can directly access the CAN bus of the engine with VCDS to read out the engine control unit, or if I absolutely have to use the indirect route via the K-line from the speedometer?

In the VW wiring diagrams, there's always mention of a CAN gateway, which seems to be located on the instrument cluster circuit board and apparently acts as an interface between the CAN bus and the K-line. I'd like to bypass the instrument cluster and directly connect the CAN high and CAN low lines from the engine control unit to the OBD connector.

Hello,

You can connect directly to the CAN bus of the engine control unit for diagnostics.

Best regards, Rainer.