U0039low severityNetwork
LIN Bus A (-) Open
on 2021 Audi S5 3.0L Turbo V6 · AWD
What this code means
The LIN bus A ground reference is open, preventing proper LIN communication.
Symptoms
- LIN slave devices not responding
- Erratic LIN device behavior
Common causes
- LIN ground wire open
- Corroded ground connection
- Broken ground splice
Diagnostic steps
- Check LIN ground continuity
- Inspect ground connection points
- Test for proper ground at LIN devices
Repair notes
Repair the open ground on the LIN bus circuit.
Other Network codes on this vehicle
U0001
High Speed CAN Communication Bus
U0002
High Speed CAN Communication Bus Performance
U0003
High Speed CAN Communication Bus (+) Open
U0004
High Speed CAN Communication Bus (+) Low
U0005
High Speed CAN Communication Bus (+) High
U0006
High Speed CAN Communication Bus (-) Open
U0007
High Speed CAN Communication Bus (-) Low
U0008
High Speed CAN Communication Bus (-) High
U0009
High Speed CAN Communication Bus Shorted Together
U0010
Medium Speed CAN Communication Bus