Lost Communication with DC/AC Converter 'A' Module
The U0288 code indicates that the main control module (PCM, ECM, or gateway) has lost serial communication, typically over the CAN bus, with the DC/AC converter 'A' module (inverter). This inverter converts DC voltage from the high-voltage system or 12V battery into AC voltage to power 120V/230V outlets. Loss of communication prevents the inverter from being managed and monitored, usually disabling the AC outlet function.
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 unpowered DC/AC converter 'A' module
- Open, short-to-ground, or short-to-voltage in the CAN bus (High/Low) wiring to the inverter module
- Damaged, corroded, or loose connectors at the inverter module or gateway
- Internal CAN bus fault (bus-off) in the inverter module
- Power or ground supply issues (B+/Ignition) to the inverter module
- Software/calibration update needed for the gateway or inverter module
3. Symptoms You Will Notice
- Inoperative 120V/230V AC power outlets
- Check Engine Light or warning message on the dash
4. Step-by-Step Diagnosis
Scan for all stored codes and note any related U-codes
Inspect the inverter module connectors and wiring for damage, corrosion, or looseness
Check power and ground circuits at the inverter module (B+ and ignition)
Test CAN bus continuity and resistance between the inverter module and the gateway
If wiring is intact, attempt to communicate with the inverter module using a scan tool; if no response, suspect a faulty module
Check for available software updates for the gateway or inverter module
5. Frequently Asked Questions
Is it safe to drive?▼
Yes, the vehicle is generally safe to drive, but the AC power outlets will not work. The issue is of medium severity and should be diagnosed soon to avoid potential battery drain or other electrical problems.
How much does it cost to fix?▼
Diagnosis typically costs $100-$200. Repair costs vary: a simple connector fix may be $50-$150, while replacing the inverter module can range from $300 to $800 or more, depending on the vehicle.