OBD-II Diagnostic Trouble Code
U0147 — Lost Communication With Gateway B
U0147 means modules lost communication with Gateway B, a secondary gateway that connects network buses on vehicles that use more than one gateway. Its messages stopped arriving within the allowed time. Where this gateway sits and which buses it connects depend on the manufacturer.
Severity 3/5
Truck-relevant
Service this week
Severity
Service this week
Lost Communication With Gateway B
Code
U0147
Category
Network
Subsystem
Network
Truck-relevant
Yes
What this means for truckers
U0147 (Lost Communication With Gateway B) — second gateway offline.
Before you replace parts — try this first
U0147 on the Network system is most often fuse, power or ground problem at gateway b — not a dead part. On commercial diesels especially, work these in order before spending money on parts:
- Confirm the symptoms. Match what your truck is doing to the Symptoms section below. If the code is set but the symptoms are not there, clear the code and re-test after a drive cycle — it may not return.
- Clean and dry the sensor connector. Water, road salt, or oil seeping into a connector is the #1 fake sensor failure. Disconnect, look for green corrosion or moisture, spray with electrical contact cleaner, dry, reseat. Many faults clear here for $0.
- Inspect the wiring harness. Trace the wire from the sensor toward the ECM — look for chafing against the engine block, melted insulation near the turbo or exhaust, or pinch points where a clamp has rubbed through.
- Test the sensor before swapping it. Most Common Causes (below) list the expected voltage or resistance range — a $20 multimeter saves a $300 sensor swap that does not fix the problem.
- Only then, replace the part. Use the OEM or a tier-1 aftermarket. Cheap sensors throw the same code in two weeks.
Symptoms
Multiple U-codes, warning lamps or missing features for modules on the bus served by Gateway B. Some modules may not respond to a scan tool. Driveability depends on which networks the gateway connects.
Common causes
- CommonFuse, power or ground problem at Gateway B ($50–$300)
- CommonDamaged network wiring or corroded connector ($150–$700)
- OccasionalLow battery or charging voltage ($100–$900)
- RareFailed Gateway B module ($600–$2500)
How to fix
Check batteries, fuses, power and grounds at Gateway B
When to use: First check
Test the network buses on both sides of the gateway for correct voltage and termination
When to use: When the module is powered but modules behind it are unreachable
Check for updates and reprogram the gateway
When to use: For intermittent dropouts with good wiring
Replace and program Gateway B
When to use: After all other checks pass
Affects most
No specific vehicle pattern found in our complaint database. This code can appear on any vehicle that supports OBD-II diagnostics.
Related
- → Browse all DTC trouble codes
- → Decode a VIN to check codes for your truck
- → Owner-operator maintenance guides
- → U0100 — Lost Communication With ECM/PCM A
- → U0101 — Lost Communication With TCM
- → U0102 — Lost Communication With Transfer Case Control Module
- → U0103 — Lost Communication With Gear Shift Module
- → U0104 — Lost Communication With Cruise Control Module
Frequently Asked Questions
Can I drive with code U0147?
U0147 is severity 3 — plan service within a few days. Performance is likely degraded already (you may feel reduced power, harsher shifts, or slightly worse fuel economy). Continuing to drive risks additional damage to adjacent components.
How much does it cost to fix U0147 on a commercial truck?
Total repair cost ranges $50–$2500 depending on the root cause. The cheapest fix is usually the first one listed below — Fuse, power or ground problem at Gateway B — which is also the most common. On commercial trucks the cost is usually higher than passenger vehicles due to part availability and shop labor rates ($120–185/hour at most truck shops, vs $90–130 at general auto shops). DIY-capable fixes (sensors, hoses, filters) are at the low end; major component replacements (turbo actuator, high-pressure fuel pump, transmission solenoid pack) are at the high end. Always diagnose with a scan tool BEFORE replacing parts — guessing wrong on a $1,500 turbo actuator when the actual issue was a $30 boost hose is a common expensive mistake.
Will U0147 fail a DOT inspection?
U0147 is generally not a direct DOT inspection fail item by itself. Inspectors focus on safety-critical systems (brakes, steering, tires, lights, hours-of-service). However, the check engine light alone can trigger additional inspection scrutiny. Best practice: fix the code and clear it before a planned inspection.
What's the difference between U0147 and related codes?
U0147 is closely related to: U0100 (Lost Communication With ECM/PCM A), U0101 (Lost Communication With TCM), U0102 (Lost Communication With Transfer Case Control Module), U0103 (Lost Communication With Gear Shift Module). These codes share the same subsystem (network) and often appear together. If you see this code, scan for the full code list — fixing the root cause usually clears multiple companion codes at once. If only U0147 is set without the companions, the issue is more isolated.
How do I prevent U0147 from coming back after a repair?
For U0147 (Lost Communication With Gateway B), prevention centers on the network system. Pay attention to ground connections at every PM — bad grounds are 70% of communication codes. Inspect harness routing for chafe points. Don't disconnect modules with the key on.