Lost Communication with Gateway A
The powertrain control module (PCM/ECM) has detected a loss of serial communication with Gateway 'A' over the vehicle's data bus (CAN, LIN, etc.). The Gateway acts as a bridge, translating and routing messages between different-speed buses (e.g., high-speed CAN, medium-speed CAN, LIN, FlexRay). A failure of this module can isolate entire sub-networks, leading to multiple system malfunctions.
1. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.
2. Most Common Causes
- Faulty or internally damaged Gateway 'A' module
- Open circuit, short to ground, or short to battery on the CAN bus (High/Low) to the Gateway
- Loose, corroded, or damaged connectors at the Gateway (bent or retracted terminals)
- Missing or defective CAN bus termination resistors
- Loss of power (B+) or ground at the Gateway module
- Software or calibration error in the Gateway or master module
- Excessive electromagnetic interference (EMI) on the wiring harness
3. Symptoms You Will Notice
- Multiple warning lights on the dashboard (e.g., Check Engine, ABS, Airbag)
- Non-functional or erratic operation of several electronic systems (e.g., infotainment, climate control, power windows)
4. Step-by-Step Diagnosis
Scan all modules for communication-related DTCs and note which modules are offline
Check for power and ground at the Gateway module using a multimeter
Inspect the CAN bus wiring and connectors for damage, corrosion, or shorts
Measure CAN bus resistance at the Gateway connector (should be ~60 ohms with termination resistors intact)
Test the Gateway module by swapping with a known-good unit (if possible) or using a scope to check bus activity
5. Frequently Asked Questions
Is it safe to drive?▼
No, it is not safe to drive. The loss of communication can cause critical systems (e.g., ABS, airbags, engine management) to fail or behave unpredictably, increasing the risk of an accident.
How much does it cost to fix?▼
Repair costs typically range from $200 to $1,200, depending on whether the issue is a simple wiring repair (low end) or requires replacing the Gateway module and reprogramming (high end).