Lost Communication With Gateway B
What does U0147 mean?
The U0147 code means the vehicle's onboard diagnostic system has detected: Lost Communication With Gateway B. This is a critical severity code.
Common Symptoms
- Some vehicle systems not communicating
- Scan tool missing certain modules
- Partial system failures -- some features work, others do not
- Warning lights for affected systems
- Intermittent module communication errors
Probable Causes (Ranked by Likelihood)
- Failed secondary gateway module Very High
- Damaged CAN bus wiring between gateway A and B High
- Power supply or ground failure at gateway B Moderate
- Gateway B software corruption Moderate
- Aftermarket device interfering with gateway communication Low
Step-by-Step Diagnostic Procedure
-
Scan all modules -- identify which ones are unreachable via gateway B
-
Check power supply and ground at the secondary gateway module
-
Inspect CAN bus wiring between gateways A and B
-
Check for aftermarket devices connected to the OBD-II port that may interfere
-
Verify gateway B software version and check for updates
Frequently Asked Questions
Can I drive with code U0147?
You may be able to drive short distances if the engine and transmission are still communicating. However, some safety systems may be disabled. Determine which systems are affected before driving.
What is gateway B?
In vehicles with multiple communication networks, gateway B is a secondary router that bridges specific CAN bus segments. It typically handles comfort or body electronics networks.
Can aftermarket devices cause U0147?
Yes. OBD-II plug-in devices, aftermarket remote starters, and other devices can interfere with CAN bus communication through the gateway. Try removing any aftermarket devices connected to the OBD-II port.