This is information and example code to control speed on Volvo/TRW electro hydraulic power steering pumps. Below is an outline of the CAN IDs and message structure needed to turn the pump on, and control the pump speed. volvoEHPSCANBasic is a basic example arduino sketch intended for ESP32. The sketch sets the pump to a fixed speed.
The volvo pump communicates at 500kbps and uses extended CAN IDs.
| CAN ID | DLC | Period | Description |
|---|---|---|---|
| 0x1ae0092c | 8 | 2000 ms | "keep alive" message, possibly from ECU/ignition/security/BCM? Byte 1 appears to be a counter, and is the only byte that seems to matter. Byte 1 changes each time the keep alive message is sent. Byte 1 only seems to rotate through [0x00, 0x40, 0x80, 0xC0] indefinitely Sample Frame: 00 00 22 E0 41 90 00 00 |
| 0x02104136 | 8 | 72 ms | Bytes 7 and 8 of this frame are likely vehicle speed and varies from 1 - 6000 decimal or 00 01 - 17 70 hex. A hex value of 00 01 turns the pump on full speed Sample Frame (full speed): BB 00 3F FF 06 E0 00 01 |