U142100: Control module for emergency call module and communication unit no communication (Unauthorized)
Diagnostic trouble code U142100 — what it means, the common
causes, and how to confirm the real fault before replacing parts.
What does U142100 mean?
U142100 indicates: Control module for emergency call module and communication unit no communication (Unauthorized).
This relates to the Network / communication system.
Common causes of U142100
No communication with emergency call module control unit and communication unit J949
Loss of communication on infotainment CAN bus or Ethernet connection to J949
Missing wake-up signal on CAN bus connection
What to check (live data)
Infotainment CAN bus communication status
Ethernet connection status between J949 and gateway/J794
CAN bus wake-up signal to J949
Emergency battery charge status
Parts often involved in U142100
Emergency call module control unit and communication unit J949
Data bus diagnostic interface J533
Emergency battery (integrated in J949, fixed 7-year replacement interval)
GPS aerial (FAKRA connection)
LTE aerial connections (FAKRA connections)
Infotainment CAN bus wiring
Ethernet wiring to J949
Don't replace parts until the root cause is confirmed — many of these codes are caused by wiring, a connector or an upstream fault, not the part itself.
Get the confirmed root cause for U142100 — on YOUR vehicle
A code is a symptom, not a diagnosis. AutoDX Pro cross-checks several
independent assessments, pinpoints the actual root cause, gives you the
exact tests to confirm it, and shows the parts — only after the cause is
confirmed. Reads your scan-tool photo and decodes your VIN with open
recalls.
U142100 is a diagnostic trouble code: Control module for emergency call module and communication unit no communication (Unauthorized).
What are the common causes of U142100?
Common causes include: No communication with emergency call module control unit and communication unit J949, Loss of communication on infotainment CAN bus or Ethernet connection to J949, Missing wake-up signal on CAN bus connection. The exact cause depends on the vehicle — confirm it before replacing parts.
Can I keep driving with U142100?
It depends on the fault and your symptoms. Some causes are minor, others can damage components or affect safety. Get the root cause confirmed before deciding.
How do I fix U142100?
Confirm the actual root cause with targeted tests first, then replace only the part that's at fault. AutoDX Pro gives you the root cause, the exact tests, and the parts for U142100 on your specific vehicle.