# How to DIY a SuzyQ Cable

### How a SuzyQ Cable Actually Works

Chromebooks with a Titan C / Cr50 / Ti50 security chip monitor the USB Type-C Configuration Channel (CC) lines for a specific resistor combination:

* **CC1 (pin A5):** Pulled to VBUS via a **22 kΩ** resistor.
* **CC2 (pin B5):** Pulled to VBUS via a **56 kΩ** resistor.

When the Chromebook detects these exact pull-up values upon insertion, it enters Debug Accessory Mode. The internal multiplexer redirects the security chip's USB lines to the USB-C **Sideband Use (SBU)** pins:

* **SBU1 (pin A8)** becomes **USB D+**.
* **SBU2 (pin B8)** becomes **USB D-**.

Once connected to your PC, the Chromebook's security chip enumerates natively on your host system as a Google USB composite device (VID:PID `18d1:5014`), exposing serial consoles for the AP and EC, as well as the CCD interface used by `gsctool` and `flashrom`.

---

### How to Build a DIY SuzyQ (No Microcontroller Required)

To build one, you only need:

1. **A male USB-C breakout board** with access to individual pins (all 24 pins exposed, or at least VBUS, GND, CC1, CC2, SBU1, and SBU2).
2. **Two resistors:** 1x 22 kΩ (1% tolerance) and 1x 56 kΩ (1% tolerance).
3. **A sacrificial USB 2.0 cable** (USB-A or USB-C on the PC side).

#### Wiring Diagram

| USB-C Male Plug (to Chromebook) | Connection / Resistor | Host USB Cable (to PC) |
| --- | --- | --- |
| **VBUS** (A4, A9, B4, B9 bridged) | Direct wire | **5V (Red)** |
| **GND** (A1, A12, B1, B12 bridged) | Direct wire | **GND (Black)** |
| **CC1** (A5) | **22 kΩ resistor** to VBUS | *(No connection to host)* |
| **CC2** (B5) | **56 kΩ resistor** to VBUS | *(No connection to host)* |
| **SBU1** (A8) | Direct wire | **D+ (White)** |
| **SBU2** (B8) | Direct wire | **D- (Green)** |

> **Crucial build note:** You **must** use a **male USB-C plug breakout** inserted directly into the Chromebook. Standard USB-C to USB-C or extension cables do not wire both CC lines end-to-end (only one CC wire exists in standard Type-C cables, with the other line used for VCONN). Splicing an existing USB-C cable will fail.

---