how to troubleshoot U1120 code in my Genesis G70 IG (2017-2023)

Learn how to troubleshoot and fix U1120 communication issues in Genesis G70 (2017-2023). Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative terminal of the battery to ensure safety.
• Ensure the vehicle is on a level surface and secured with jack stands if working underneath.

2. Inspect Wiring and Connectors

• Sub-steps:
  • Visually inspect the wiring harnesses connected to the affected modules for signs of wear, fraying, or shorts.
  • Check connectors for corrosion or loose connections.
  • Use a multimeter to measure resistance across the connectors to ensure proper connectivity.
• Tools Required: Multimeter, flashlight

3. Repair or Replace Damaged Components

• Sub-steps:
  • Repair any damaged wires by splicing in new wire and using heat shrink tubing to protect the repair.
  • Clean corrosion from connectors using electrical contact cleaner and reconnect securely.
  • Replace any connectors that are beyond repair with OEM parts.
• Tools Required: Wire cutters/strippers, soldering iron (if splicing), electrical tape

4. Check Module Power and Ground

• Sub-steps:
  • Reconnect the battery and power on the vehicle.
  • Use a multimeter to check for voltage at the power and ground pins of the affected module.
  • If voltage is not present, trace back to the power and ground sources to identify and repair the issue.
• Tools Required: Multimeter

5. Reassemble and Clear Codes

• Sub-steps:
  • Once repairs are complete, reconnect any removed components.
  • Use the OBD-II scanner to clear any fault codes from the system.
  • Perform a test drive to ensure that the U1120 code does not return.
• Tools Required: OBD-II scanner