Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2004 Cadillac CTS VFACTORY OEM SERVICE PROCEDURE
Data Link Communication DTCS
DATA LINK COMMUNICATION DIAGNOSTIC TROUBLE CODE (DTC) LIST
| DTC | Description |
|---|---|
| DTC U0001 | Transmit Error Counter Above Threshold |
| DTC U0100 To U0299 | Lost Communications With U0XXX |
| DTC U1000 and U1255 | Class 2 Communication Malfunction |
| DTC U1001 To U1254 | Lost Communications With U1XXX |
| DTC U1300, U1301, or U1305 | Class 2 Data Link Shorted |
| DTC U2100 | Controller Area Network (CAN) Bus Communication |
| DTC U2102 | More Controllers On Bus Than Programmed |
| DTC U2106 | Lost Communications With Transmission Control System |
Factory Service Tools
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.
Rather have a pro handle this?
A certified mobile mechanic comes to your home or office. They bring the tools, you stay comfortable. No tow truck, no waiting room, no surprises.
Comes to youSame-day available12-month warranty
Get a Free QuoteNo obligation. See pricing before you book.