U2023low severityNetwork
Fault Received from External Node
on 2007 Chevrolet Impala 3.5L V6 · FWD
What this code means
A control module has received a fault notification from another module on the network, indicating a dependent system has a problem.
Symptoms
- Warning light for secondary system
- Cascading DTCs across modules
- Feature limited due to external fault
- System in reduced functionality mode
Common causes
- Primary fault exists in another module
- Dependent system has active DTC
- Communication issue causing fault propagation
- Software glitch sending false fault signal
Diagnostic steps
- Scan all modules for DTCs
- Find the primary fault code
- Address the original fault first
- Clear codes after primary repair
- Retest all systems
Repair notes
This is a cascading code. Find and fix the original DTC in the source module first.
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