Diagnostic trouble code U16A700 — what it means, the common
causes, and how to confirm the real fault before replacing parts.
What does U16A700 mean?
U16A700 indicates: CAN data bus 4 No communication.
This relates to the Network / communication system.
Common causes of U16A700
Open circuit in CAN-High wire
Open circuit in CAN-Low wire
Short circuit between CAN-High and CAN-Low
Short circuit between CAN-High and positive voltage
Short circuit between CAN-High and Ground
Short circuit between CAN-Low and Ground
Short circuit between CAN-Low and positive voltage
Control module disconnected from bus (bus OFF) at least twice due to internal error counter threshold exceeded
Message time-out triggered by at least 10 messages not received
What to check (live data)
CAN-High wire voltage (DSO Channel A)
CAN-Low wire voltage (DSO Channel B)
Single-wire vs two-wire CAN transmission pattern via DSO
Message cycle timing (delays indicating missed messages; threshold: at least 10 messages not received triggers message time-out)
Parts often involved in U16A700
CAN-High wire
CAN-Low wire
CAN bus control module(s)
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 U16A700 — 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.
U16A700 is a diagnostic trouble code: CAN data bus 4 No communication.
What are the common causes of U16A700?
Common causes include: Open circuit in CAN-High wire, Open circuit in CAN-Low wire, Short circuit between CAN-High and CAN-Low, Short circuit between CAN-High and positive voltage. The exact cause depends on the vehicle — confirm it before replacing parts.
Can I keep driving with U16A700?
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 U16A700?
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 U16A700 on your specific vehicle.