C139EF0 on Audi: Maneuver braking with steering assist Status feedback for HMI implausible (Unauthorized)
Diagnostic trouble code C139EF0 on Audi vehicles — what it means, the common
causes, and how to confirm the real fault before replacing parts.
What does C139EF0 mean?
C139EF0 indicates: Maneuver braking with steering assist Status feedback for HMI implausible (Unauthorized).
This relates to the Chassis system.
Common causes of C139EF0
Status feedback for manoeuvre braking with steering assist to HMI is implausible or unauthorized
Fault in communication between driver assist systems control unit J1121 and MMI/instrument cluster
ABS control unit J104 reporting a fault (which can deactivate manoeuvre braking)
PDW sensors failure
System unavailable due to technical fault causing function symbol not to be shown on MMI
What to check (live data)
Manoeuvre assist function symbol status on MMI (white/not crossed out = active; white/crossed out = temporarily deactivated; not shown = switched off or technical fault; grey/crossed out = speed exceeded 10 km/h reversing)
Vehicle speed (manoeuvre braking active between 1.5 km/h and 10 km/h)
Parking aid (PDW) activation status
Door/tailgate open status
ABS control unit fault status
PDW sensor status
Parts often involved in C139EF0
Driver assist systems control unit J1121
ABS control unit J104
Ultrasonic sensors (PDW sensors)
Overhead view cameras
MMI display unit
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 C139EF0 — 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.
C139EF0 is a diagnostic trouble code: Maneuver braking with steering assist Status feedback for HMI implausible (Unauthorized).
What are the common causes of C139EF0 on an Audi?
Common causes include: Status feedback for manoeuvre braking with steering assist to HMI is implausible or unauthorized, Fault in communication between driver assist systems control unit J1121 and MMI/instrument cluster, ABS control unit J104 reporting a fault (which can deactivate manoeuvre braking), PDW sensors failure. The exact cause depends on the vehicle — confirm it before replacing parts.
Can I keep driving an Audi with C139EF0?
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 C139EF0 on an Audi?
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 C139EF0 on your specific Audi.