WARNING: This page is about a different car, the 2020 Cadillac CT4. However, it is still accessible from the selected car via links, so may be relevant.

NOTE:

Before attempting to perform the Serial Data Authentication Configuration procedure,

Make sure all CAN control modules are connected and communicating.
Diagnose the following communication DTCs first: DTC U0073-U007E, U0100-U02FF, U1100-U12FF, U1600-U17FF, U1977, U1978, U2200-U23FF, and U2400-U25FF.

If DTC U1962 is stored only as a history DTC and not retrieved as a current DTC, do not perform the Serial Data Authentication Configuration procedure.

Ignition/Vehicle OFF, keep the key inside the vehicle.
Access the Service Programming System (SPS) and follow the on-screen instructions.

NOTE:

The Serial Data Authentication Configuration button is located in the following location:

To the left side of the SPS Supported Controllers screen in the TIS system.
In the lower right corner of the SPS Supported Controllers screen in the Techline Connect system.

On the SPS Supported Controllers screen, select Serial Data Authentication Configuration button and follow the on-screen instructions.
Ignition/Vehicle OFF, all access doors closed, all vehicle systems OFF, and all keys at least 3 m (9.8 ft) away from vehicle. Disconnect the scan tool from the vehicle. It may take up to 10 min for all vehicle systems to power down.
Ignition ON/Vehicle In Service Mode.
Using a scan tool, clear DTCs.

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.

Safety Warning

Serial Data Authentication Configuration

Use the Manual With the Right Hardware

When to See a Mechanic