U1000
CAN Communication Bus Fault
1999-2000 BMW 323i E46 2.5L I6 🇬🇧
Moderate SeverityNetwork
Description
General manufacturer-level CAN bus communication fault detected. Multiple modules may report this code simultaneously.
Symptoms
- Warning lights on
- Multiple communication DTCs
- Intermittent electrical features
- Scan tool intermittent connection
Common Causes
- CAN bus wiring damage
- Module failure corrupting bus
- Poor ground connection
- Aftermarket device on CAN bus
- Termination resistor fault
Diagnostic Steps
- Check CAN bus resistance (should be ~60 ohms)
- Scope CAN bus signals
- Remove aftermarket devices
- Check all CAN bus connectors
- Isolate modules to find fault source
Repair Notes
Systematic CAN bus diagnosis required. Start with bus resistance measurement and visual inspection.
Related Codes
Other Network Codes
- U0001High Speed CAN Communication Bus
- U0002High Speed CAN Communication Bus Performance
- U0003High Speed CAN Communication Bus (+) Open
- U0004High Speed CAN Communication Bus (+) Low
- U0005High Speed CAN Communication Bus (+) High
- U0006High Speed CAN Communication Bus (-) Open
- U0007High Speed CAN Communication Bus (-) Low
- U0008High Speed CAN Communication Bus (-) High
- U0009High Speed CAN Communication Bus Shorted Together
- U0010Medium Speed CAN Communication Bus
U1000 on Other Vehicles
Common Questions
What does code U1000 mean on a 1999-2000 BMW 323i E46?
U1000 stands for "CAN Communication Bus Fault". General manufacturer-level CAN bus communication fault detected. Multiple modules may report this code simultaneously.
What are the symptoms of U1000 on a BMW 323i E46?
Common symptoms of U1000 include: Warning lights on, Multiple communication DTCs, Intermittent electrical features, Scan tool intermittent connection.
What causes U1000 on a 1999-2000 BMW 323i E46?
Common causes of U1000 include: CAN bus wiring damage, Module failure corrupting bus, Poor ground connection, Aftermarket device on CAN bus, Termination resistor fault.