What it means
The cryptographic key or certificate used to authenticate inter-module communication is missing or invalid.
At a glance
- Usually lights the warning light of the system that lost communication
- The engine or gearbox may go into limp mode
How it works
Modules use an authentication key or certificate to verify that messages exchanged across the vehicle network come from an authorized source. The receiving system checks that credential; this code sets when the key or certificate is missing or invalid, potentially restricting communication.
Common causes
Most likely first.
- Key not provisioned
- Gateway module routing CAN messages incorrectly
- CAN terminating resistor (120 Ω) drifted out of spec
Symptoms
- Multiple warning lights may illuminate
- Affected modules may go into limp mode or shut down
- Specific functions inoperative depending on module
- Diagnostic tools may show communication faults
How to diagnose it
- Scan all modules for authentication and network codes, and identify where the missing or invalid credential is reported.
- Save freeze-frame and live status data, including which modules are offline or in a restricted mode.
- Review recent module replacement, programming, or configuration work that may have left the communication credential unprovisioned.
- Inspect gateway and network connectors, wiring, power, and grounds for faults that could interrupt credential exchange.
- Check credential provisioning and gateway message routing using supported diagnostic procedures; compare network termination with the manufacturer's specification if network faults remain.
Common fixes
- Restore the correct module configuration after programming or replacement.
- Provision the required authentication key or certificate through the supported procedure.
- Repair confirmed gateway, wiring, connector, power, or ground faults.
- Correct a confirmed CAN termination fault or replace a module only when testing shows it cannot authenticate.
Can I keep driving?
This fault can restrict module communication and trigger limp mode, so avoid demanding driving and stop if essential controls or safety features are affected. Have the authentication fault diagnosed promptly.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.