Dell XPS 13 9340 Intel Core Ultra 7 155H Thunderbolt 4 Not Working Fix Windows 11

The Thunderbolt 4 ports on your Dell XPS 13 9340 Intel Core Ultra 7 155H do not detect connected devices — a Thunderbolt dock shows no devices, an external GPU enclosure is not recognized, or the Thunderbolt port works for USB but not Thunderbolt-specific features. Intel Thunderbolt driver updates and BIOS security settings restore full Thunderbolt 4 functionality on the XPS 13 9340.

“Dell XPS 13 9340 Core Ultra 7 155H Thunderbolt dock showed nothing in Device Manager. Dell SupportAssist had Intel Thunderbolt Controller firmware and driver updates pending. After installing both and restarting, dock detected immediately with all USB ports and display output working.” – Syafiq, consultant from KLCC

Update Intel Thunderbolt Driver via Dell SupportAssist

Open Dell SupportAssist and run System Update. Install Intel Thunderbolt Controller Driver and Intel Thunderbolt Firmware updates together — both components must be current for Thunderbolt 4 device enumeration to complete correctly. After installation, restart the XPS 13 9340 and connect the Thunderbolt device. Verify in Device Manager – System devices that Intel Thunderbolt Controller appears without a yellow warning icon. The updated Thunderbolt firmware fixes PCIe tunnel initialization timing that determines how quickly new devices are detected and how reliably multi-device Thunderbolt daisy chains enumerate on the Dell XPS 13 9340 Intel Core Ultra 7 155H platform.

Set Thunderbolt Security in Dell BIOS

Restart and press F2 to enter Dell BIOS. Navigate to Connection – Thunderbolt Adapter Configuration or Security – Thunderbolt Security Level. Options include No Security (all devices allowed without authorization), User Authorization (each new device must be approved once), and Secure Connect (requires certificate). Set to No Security for personal use or User Authorization for corporate environments. Secure Connect mode requires device certificates not present on consumer docks and eGPU enclosures, causing them to appear as USB devices only without full Thunderbolt PCIe bandwidth on the XPS 13 9340.

Frequently Asked Questions

How do I fix Thunderbolt 4 not working on Dell XPS 13 9340 Intel Core Ultra 7 155H?

Update Intel Thunderbolt Controller Driver and firmware via Dell SupportAssist. Set BIOS Thunderbolt Security to No Security. Use certified Thunderbolt 4 cable. Restart after each change and reconnect Thunderbolt device.

Why does Dell XPS 13 9340 Intel Core Ultra 7 155H not detect Thunderbolt devices?

Thunderbolt BIOS security set to Secure Connect (most common in enterprise setups). Change to No Security or User Authorization. Also update Intel Thunderbolt driver via Dell SupportAssist before testing again.

Does Dell XPS 13 9340 Intel Core Ultra 7 155H support Thunderbolt 4?

Yes – two Thunderbolt 4 USB-C ports at 40Gbps. Supports dual 4K display, Thunderbolt docks, eGPU, NVMe storage, and USB 3.2 Gen 2 10Gbps. USB Power Delivery up to 100W for laptop charging via dock.

Why does Dell XPS 13 9340 Thunderbolt dock not charge the laptop?

Dock adapter below 65W, or USB-C cable is charge-only without data pins. Use dock’s original adapter (90W+ recommended). Use certified Thunderbolt 4 cable with full pin implementation for both data and charging.

Conclusion

Dell XPS 13 9340 Intel Core Ultra 7 155H Thunderbolt 4 not working in Windows 11 resolves by updating both Intel Thunderbolt Controller Driver and firmware via Dell SupportAssist to fix PCIe tunnel enumeration failures. BIOS Thunderbolt Security Level change from Secure Connect to No Security or User Authorization allows consumer docks and eGPU enclosures without device certificates to fully enumerate at Thunderbolt 4 bandwidth. Certified Thunderbolt 4 cable use confirms the physical connection supports full pin implementation required for Thunderbolt data transfer alongside USB Power Delivery charging on the Dell XPS 13 9340 Intel Core Ultra 7 155H platform.