U0101
Lost Communication with TCM
2018-2025 Fiat Cronos 1.3L I4 Flex Firefly
High SeverityNetworkGeneric (SAE)
Description
Cannot communicate with the Transmission Control Module.
Symptoms
- Check Engine Light
- Transmission in limp mode
- Harsh shifting or no shifting
- Trans warning light
Common Causes
- TCM power/ground failure
- CAN bus wiring to TCM
- TCM failure
- Fuse blown
Diagnostic Steps
- Check TCM fuses
- Test power and ground at TCM
- Check CAN bus wiring
- Try direct communication with TCM
Repair Notes
Check fuses and power supply. Verify CAN bus.
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
U0101 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 U0101 mean on a 2018-2025 Fiat Cronos?
U0101 stands for "Lost Communication with TCM". Cannot communicate with the Transmission Control Module.
What are the symptoms of U0101 on a Fiat Cronos?
Common symptoms of U0101 include: Check Engine Light, Transmission in limp mode, Harsh shifting or no shifting, Trans warning light.
What causes U0101 on a 2018-2025 Fiat Cronos?
Common causes of U0101 include: TCM power/ground failure, CAN bus wiring to TCM, TCM failure, Fuse blown.