Lost Communication with ECM/PCM B
2008-2008 Mazda Tribute 2.5L I4
The 2008 Mazda Tribute is equipped with a 2.5L inline-4 engine. Below you'll find detailed u0115 diagnostic code information including labor time estimates, cost ranges, and technician notes specific to this engine configuration.
Description
Cannot communicate with the secondary Engine Control Module on vehicles with dual ECMs.
Symptoms
- Partial engine management failure
- Some cylinders not controlled
- Reduced power
- Check Engine Light
Common Causes
- ECM B power failure
- CAN bus wiring
- ECM B failure
- Fuse blown
- Connector issue
Diagnostic Steps
- Check ECM B fuse
- Test power and ground
- Check CAN wiring
- Try direct communication with ECM B
- Compare ECM A and B communication status
Repair Notes
Dual ECM vehicles are less common. Check power supply to secondary ECM.
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
U0115 on Other Vehicles
Common Questions
What does code U0115 mean on a 2008-2008 Mazda Tribute?
U0115 stands for "Lost Communication with ECM/PCM B". Cannot communicate with the secondary Engine Control Module on vehicles with dual ECMs.
What are the symptoms of U0115 on a Mazda Tribute?
Common symptoms of U0115 include: Partial engine management failure, Some cylinders not controlled, Reduced power, Check Engine Light.
What causes U0115 on a 2008-2008 Mazda Tribute?
Common causes of U0115 include: ECM B power failure, CAN bus wiring, ECM B failure, Fuse blown, Connector issue.
Last updated: March 2026