U0147: Lost Communication with Gateway B Module
The U0147 code indicates that the vehicle's control module has detected a loss of communication on the data bus with the Gateway 'B' module. The Gateway acts as a communication hub that translates and transfers data between different vehicle networks (e.g., high-speed CAN, low-speed CAN, LIN, or Ethernet). The 'B' designation typically refers to a secondary or zone-specific gateway module, depending on the manufacturer's network architecture. This fault prevents control modules from exchanging critical information, potentially affecting multiple vehicle systems.
1. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.
2. Most Common Causes
- Internal failure of the Gateway 'B' module
- Open or short circuit in the data bus wiring (CAN High, CAN Low, or specific communication lines)
- Faulty power supply or ground circuit to the Gateway 'B' module
- Corrosion or damage to the module connectors or pins
- Electromagnetic interference affecting signal integrity
- Another module on the network causing a bus communication collapse
3. Symptoms You Will Notice
- Multiple warning lights on the dashboard (e.g., Check Engine, ABS, Airbag)
- Malfunction of systems that rely on network communication (e.g., infotainment, climate control, driver assistance features)
4. Step-by-Step Diagnosis
Scan for all stored codes and freeze frame data to identify related faults
Inspect the Gateway 'B' module connectors and wiring for corrosion, damage, or loose connections
Check power and ground circuits at the Gateway 'B' module using a multimeter
Perform a network communication test (e.g., using a scan tool to monitor CAN bus activity)
If wiring and power are okay, suspect a failed Gateway 'B' module and replace it
5. Frequently Asked Questions
Is it safe to drive?▼
No, this is a high-severity fault. Driving with a loss of communication can lead to unpredictable behavior of critical systems (e.g., brakes, transmission, airbags). It is recommended to have the vehicle towed to a repair shop.
How much does it cost to fix?▼
The cost varies widely depending on the root cause. Diagnosing the issue typically costs $100-$200. If the Gateway module needs replacement, parts and labor can range from $400 to $1,200 or more, especially if programming is required.