U0127
Lost Communication with Parking Brake Control Module
2002-2009 GMC Envoy 4.2L I6
High SeverityNetworkGeneric (SAE)
Description
Cannot communicate with the electronic parking brake module.
Symptoms
- Parking brake warning light
- Electronic parking brake inoperative
- Brake warning message
- Cannot release parking brake
- Hill hold not working
Common Causes
- EPB module failure
- CAN bus wiring
- Module power loss
- Fuse blown
- EPB actuator failure
Diagnostic Steps
- Check EPB module fuse
- Test module power and ground
- Check CAN wiring
- Try manual EPB release procedure
- Test EPB actuator motors
Repair Notes
If parking brake is stuck engaged, use manual release procedure first. Check fuses.
Related Codes
Other Network Codes
- U0001High Speed CAN Communication Bus
- U0001High Speed CAN Communication Bus
- U0002High Speed CAN Communication Bus Performance
- U0002High Speed CAN Communication Bus Performance
- U0003High Speed CAN Communication Bus (+) Open
- U0003High Speed CAN Communication Bus (+) Open
- U0004High Speed CAN Communication Bus (+) Low
- U0004High Speed CAN Communication Bus (+) Low
- U0005High Speed CAN Communication Bus (+) High
- U0005High Speed CAN Communication Bus (+) High
U0127 on Other Vehicles
Common Questions
What does code U0127 mean on a 2002-2009 GMC Envoy?
U0127 stands for "Lost Communication with Parking Brake Control Module". Cannot communicate with the electronic parking brake module.
What are the symptoms of U0127 on a GMC Envoy?
Common symptoms of U0127 include: Parking brake warning light, Electronic parking brake inoperative, Brake warning message, Cannot release parking brake, Hill hold not working.
What causes U0127 on a 2002-2009 GMC Envoy?
Common causes of U0127 include: EPB module failure, CAN bus wiring, Module power loss, Fuse blown, EPB actuator failure.