MCP-2515: Connect CAN-Low line to ground

Translated on 08-07-2026, 9:19.

hello,
Is there a command to ground the CAN low line of the MCP2515 to wake up the ECUs in a car?

Translated on 08-07-2026, 9:19.

jaja508 wrote:

hello,
gibt es ein command um beim mcp-2515,dessen can low leitung auf ground zu schalten um so die Steuergeräte im Auto aufzuwecken?

Hello,

Wouldn't the CAN transceiver used and its wiring configuration be the correct area to investigate?

https://www.canhack.de/en/viewtopic.php?t=1963
already found?

Best regards, Rainer.

CAN-Diagnose · Translated on 08-07-2026, 9:21.

According to the datasheet, the MCP2515 goes into BusOff mode if a signal line is disrupted. You would then need to read the error register. If you can do that, the control unit is already active, so you don't need to wake it up.

I suspect you want to passively wake up the control unit. Instead of pulling a bus level to ground (which it already is in low-power mode), you send a CAN frame that wakes up the transceiver. The transceiver then wakes up the SBC (System Basic Chip) via an inhibit signal.

Alternatively, you could use a wake-up line, similar to what VW uses, but instead of connecting it to the transceiver, it would be directly connected through a low-side switch (OBD wake-up bypass).