No Communication With Traffic MasterModule
Your vehicle's main computer can't talk to the traffic management module, like a radio that won't pick up the signal. This usually means a wiring problem, loose connection, or a failed module that handles traffic sign recognition and related safety features.
The ECU sends periodic CAN bus messages to the Traffic Master Module and expects acknowledgment responses within a specific timeframe. If no valid response is received after multiple attempts, the ECU logs a communication timeout fault. The system continuously monitors signal integrity and message sequencing.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| CAN Bus Response Time | < 100 ms per message | > 500 ms or no response after 3 attempts |
| Module Detection Status | Module identified at startup | Module not detected or invalid signature |
Code B2201 is a low-severity fault. Your vehicle is generally safe to drive to a workshop for diagnosis. However, do not ignore it indefinitely — low-severity codes often indicate developing problems that become expensive if neglected. Book a diagnostic appointment within 2–4 weeks. If you notice any additional symptoms (rough running, power loss, unusual smells), treat it as higher priority.
Once the fault is repaired, B2201 can be cleared using any OBD-II scanner. Connect the scanner, navigate to "Clear Codes" or "Erase DTCs," and confirm. The check engine light turns off immediately.
The code will return if the root cause was not actually fixed. The ECM re-detects the fault within 1–3 drive cycles and sets the code again.