Secondary gateway module offline on multi-gateway architectures.
Common symptoms
- Partial vehicle function loss
- Cluster of U-codes
Typical causes
- Failed gateway B
- CAN wiring between subnets
- Aftermarket accessory on secondary bus
What scanner do you need?
Full-system scanner (engine, ABS, SRS, transmission, service resets)
Use live data and freeze frame to confirm the fault before replacing parts. ABS, SRS, and network U-codes usually require a full-system scanner.
Diagnostic tips
- Record freeze frame data when the code first sets
- Clear the code only after fixing the root cause
- Check for related pending codes that point to a common issue
- Verify battery voltage is above 12.4V before chasing sensor codes