U0115
Lost Communication with ECM/PCM B
2004-2007 Buick Rainier 4.2L I6
Critical SeverityNetworkGeneric (SAE)
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 2004-2007 Buick Rainier?
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 Buick Rainier?
Common symptoms of U0115 include: Partial engine management failure, Some cylinders not controlled, Reduced power, Check Engine Light.
What causes U0115 on a 2004-2007 Buick Rainier?
Common causes of U0115 include: ECM B power failure, CAN bus wiring, ECM B failure, Fuse blown, Connector issue.