Control Module Communication Bus A Off
2018-2025 Fiat Cronos 1.0L I4 Flex Firefly
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
Fiat 124 Spider
2017-2020 1.4L I4 Turbo
Fiat 126p Maluch
1973-2000 0.65L I2 Air-Cooled
Fiat 126p Maluch
1987-2000 0.7L I2 Air-Cooled
Fiat 500
2012-2019 1.4L I4
Fiat 500 Abarth
2012-2019 1.4L I4 Turbo
Fiat 500 BR
2011-2020 1.4L I4 Flex Fire Evo
Fiat 500 PL
2007-2025 1.0L I3 Hybrid FireFly 70
Fiat 500 PL
2007-2025 1.2L I4 Fire 69
Common Questions
What does code U0073 mean on a 2018-2025 Fiat Cronos?
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 Fiat Cronos?
Common symptoms of U0073 include: Multiple systems down, Multiple warning lights, Vehicle may not start, No scan tool communication.
What causes U0073 on a 2018-2025 Fiat Cronos?
Common causes of U0073 include: CAN bus wiring shorted or open, Termination resistor failure, Module failure shorting the bus, Major wiring harness damage.