Lost Communication With Information Center B
Your vehicle's main computer lost contact with an information center module, like a phone losing signal to a tower. This is a communication network fault that prevents data sharing between critical control modules.
The ECM monitors CAN bus communication signals to Information Center B at regular intervals. When expected messages fail to arrive within a defined timeout period, the ECM detects a loss of communication and sets this fault code.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| CAN Bus Message Timeout | Message received every 100-500ms | No message received for >2 seconds |
| CAN Bus Voltage | 0-5V digital signal with proper oscillation | No signal activity or stuck high/low state |
Code U0157 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, U0157 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.