# 5.4 | Connecting COMMAND to the ISOBUS

### ECU Mounted In-cab[![image.png](https://docs.t3rra.com/uploads/images/gallery/2025-05/scaled-1680-/prQimage.png)](https://docs.t3rra.com/uploads/images/gallery/2025-05/prQimage.png)

With the **COMMAND** ECU mounted in-cab:

1. Locate the in-cab 4-way ISOBUS connector.
2. Connect the 4-way ISOBUS connection on the **T3H-C006** cab breakout to the connector.
3. Use an additional adapter if connecting to 9-way cab ISO receptacle.

### ECU Mounted at Rear of Tractor

With the **COMMAND** ECU mounted at the rear panel or near the ISOBUS breakaway plug:

1. Disconnect the existing 4-way plug from the ISOBUS implement breakaway connector.
2. Connect the disconnected plug to the receptacle on the ISOBUS "T" connection on the T3H-C005 external breakout.
3. Connect the 4-way ISOBUS "T" plug into the ISOBUS implement breakaway connector.

[![image.png](https://docs.t3rra.com/uploads/images/gallery/2025-07/scaled-1680-/ePVWoCuJGpPFqvGH-image.png)](https://docs.t3rra.com/uploads/images/gallery/2025-07/ePVWoCuJGpPFqvGH-image.png)