U0148
Lost Communication With Serial Data Gateway Module C
Network / communication
Generic OBD-II
Medium
What it means
U0148 sets when modules lose communication with serial data gateway module C. The gateway routes messages between the vehicle's separate data buses, so losing it can block communication across whole networks — expect multiple warning lights and several unrelated features failing together, not just one.
Medium
Can I keep driving? Uncertain — because the gateway links networks, losing it can disable many features and light up multiple warnings at once; diagnose before relying on the car.
Common symptoms
What you'll notice
- Several warning lights on at once
- Multiple modules unreachable with a scan tool
- Widespread feature loss across different systems
- A cluster of lost-communication U-codes
Common causes
Most likely first
- Blown fuse or lost power/ground to the gateway moduleLikely
- Damaged or corroded wiring/connector at the gatewayCommon
- CAN bus fault on one of the buses the gateway linksCommon
- Failed gateway moduleLess often
- Low system voltageLess often
How to diagnose & fix
Work through it in order
- Scan all modules and note the full set of communication codes to see the scope.
- Check the gateway's fuse, power, and ground.
- Inspect the gateway connectors and the buses it links for damage or corrosion.
- Measure bus resistance on the affected networks (about 60 ohms when terminated).
- If power and bus wiring are good, the gateway module is the likely fault.
FAQ
Quick answers
Is it safe to drive with U0148?+
Be cautious — the gateway ties networks together, so its loss can disable features across the car. Get it diagnosed before depending on the vehicle.
Can I just clear U0148?+
It returns while the gateway is offline. Restore power, wiring, or the module first, then clear and retest.
Related codes
Often seen with U0148
Read & clear U0148 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX