U0138
Lost Communication with All Terrain Control Module
2014-2021 Mazda Mazda6 2.5L I4
Moderate SeverityNetworkGeneric (SAE)
Description
Cannot communicate with the off-road or terrain management control module.
Symptoms
- Off-road mode not available
- Terrain select not working
- 4WD features limited
- Terrain response warning
Common Causes
- Terrain module failure
- CAN bus wiring
- Module power loss
- Fuse blown
Diagnostic Steps
- Check terrain module fuse
- Test power and ground
- Check CAN wiring
- Test terrain mode switch
- Scan for terrain module DTCs
Repair Notes
Check fuses and mode selector switch. Module may be integrated with transfer case controller.
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
U0138 on Other Vehicles
Common Questions
What does code U0138 mean on a 2014-2021 Mazda Mazda6?
U0138 stands for "Lost Communication with All Terrain Control Module". Cannot communicate with the off-road or terrain management control module.
What are the symptoms of U0138 on a Mazda Mazda6?
Common symptoms of U0138 include: Off-road mode not available, Terrain select not working, 4WD features limited, Terrain response warning.
What causes U0138 on a 2014-2021 Mazda Mazda6?
Common causes of U0138 include: Terrain module failure, CAN bus wiring, Module power loss, Fuse blown.