U0073
Control Module Communication Bus A Off
1999-2000 BMW 323i E46 2.5L I6 🇬🇧
Critical SeverityNetwork
Description
CAN bus A is not communicating. Complete loss of communication on the primary bus.
Symptoms
- Multiple systems down
- Multiple warning lights
- Vehicle may not start
- No scan tool communication
Common Causes
- CAN bus wiring shorted or open
- Termination resistor failure
- Module failure shorting the bus
- Major wiring harness damage
Diagnostic Steps
- Check CAN bus voltage levels
- Measure bus resistance
- Isolate bus segments
- Check for physical damage to wiring
Repair Notes
Major network failure. Systematic diagnosis required.
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
U0073 on Other Vehicles
Common Questions
What does code U0073 mean on a 1999-2000 BMW 323i E46?
U0073 stands for "Control Module Communication Bus A Off". CAN bus A is not communicating. Complete loss of communication on the primary bus.
What are the symptoms of U0073 on a BMW 323i E46?
Common symptoms of U0073 include: Multiple systems down, Multiple warning lights, Vehicle may not start, No scan tool communication.
What causes U0073 on a 1999-2000 BMW 323i E46?
Common causes of U0073 include: CAN bus wiring shorted or open, Termination resistor failure, Module failure shorting the bus, Major wiring harness damage.