U1900moderate severityNetwork
CAN Communication Bus Fault - Received Error
on 2014-2021 Mazda Mazda6 2.5L I4 · FWD
What this code means
A module received corrupted or invalid data over the CAN bus, indicating a communication error on the network. This is similar to generic P-code U0001 for high-speed CAN bus issues.
Symptoms
- Multiple warning lights on dash
- Intermittent gauge or feature failure
- Modules not communicating
Common causes
- Faulty CAN wiring or connector
- Corroded or loose ground connection
- Failing control module on bus
- Failed CAN transceiver
Diagnostic steps
- Scan all modules for stored U-codes
- Inspect CAN wiring and connectors for damage
- Check CAN bus resistance and voltage
- Isolate faulty module by disconnecting nodes
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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