U1000high severityNetwork
CAN Communication Circuit
on 2003 Infiniti FX45 4.5L V8 · AWD
What this code means
A control module lost communication over the CAN bus network. No direct OBD P-code equivalent, but similar to U0100-series generic codes.
Symptoms
- Multiple warning lights on
- Erratic gauge readings
- Systems not responding
Common causes
- Faulty CAN bus wiring or connector
- Bad ground connection
- Failed control module
- Corroded terminals
Diagnostic steps
- Scan all modules for stored codes
- Inspect CAN bus wiring and connectors
- Check CAN resistance (should be ~60 ohms)
- Test module power and grounds
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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