Lost Communication With Information Center A
Your vehicle's main computer has lost contact with an information center module, like a phone losing signal to a tower. This communication breakdown prevents proper system coordination and data sharing between control modules.
The ECU monitors CAN bus communication frames from the Information Center module at regular intervals, typically every 100-500 milliseconds. When expected messages fail to arrive within the timeout window or checksums fail validation, a communication fault is recorded.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| CAN Bus Message Timeout | Message received within 500ms intervals | No valid message received for >1 second |
| Message Checksum Validity | Checksum matches expected calculation | Checksum mismatch or corrupted data detected |
Code U0156 is a moderate fault. You can generally drive to a workshop, but avoid long trips or high-load driving (motorway, uphill towing) until it is diagnosed. If the code keeps returning after clearing, or if you notice the symptoms listed above worsening, do not delay professional diagnosis. Many moderate codes have multiple possible root causes — a mechanic with live OBD data can identify the exact fault more efficiently than part-by-part trial and error.
Once the fault is repaired, U0156 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.