U0046
Vehicle Communication Bus B Off
1992-1996 BMW 318is E36 1.8L I4 🇩🇪
High SeverityNetwork
Description
CAN bus B is completely offline. No communication on the secondary CAN bus.
Symptoms
- Secondary systems inoperative
- Body control functions down
- Climate control offline
- Entertainment system not communicating
Common Causes
- CAN bus B wiring shorted or open
- Bus B termination resistor failure
- Module pulling down bus B
- Major connector failure
Diagnostic Steps
- Measure bus B resistance
- Check bus B voltage levels
- Isolate bus B segments
- Inspect bus B connectors
Repair Notes
Complete bus B failure requires systematic wiring diagnosis.
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
U0046 on Other Vehicles
Common Questions
What does code U0046 mean on a 1992-1996 BMW 318is E36?
U0046 stands for "Vehicle Communication Bus B Off". CAN bus B is completely offline. No communication on the secondary CAN bus.
What are the symptoms of U0046 on a BMW 318is E36?
Common symptoms of U0046 include: Secondary systems inoperative, Body control functions down, Climate control offline, Entertainment system not communicating.
What causes U0046 on a 1992-1996 BMW 318is E36?
Common causes of U0046 include: CAN bus B wiring shorted or open, Bus B termination resistor failure, Module pulling down bus B, Major connector failure.