how to fix the P0138 code on my Genesis G70 IG (2017-2023)

Learn how to diagnose and fix P0138 high voltage signal from the oxygen sensor in Genesis G70 (2017-2023). Step-by-step guide with tools and procedures.

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Allow the vehicle to cool down if the engine has been running.

2. Inspect and Repair Wiring

• Tools Required: Wire strippers, electrical tape, multimeter
• Inspect the wiring harness leading to the bank 1 oxygen sensor for any signs of damage or wear.
• Repair any damaged wires by cutting them cleanly and splicing in new wire, ensuring a secure connection and covering with electrical tape.

3. Replace the Oxygen Sensor

• Tools Required: O2 sensor socket, ratchet and extension, torque wrench
• Locate the bank 1 oxygen sensor (usually found in the exhaust manifold or upstream of the catalytic converter).
• Use the O2 sensor socket to carefully remove the old sensor by turning it counterclockwise.
• Apply anti-seize compound to the threads of the new oxygen sensor to ensure a secure fit and prevent it from seizing in the future.
• Install the new sensor by threading it into the exhaust and tightening it to the manufacturer-recommended torque specification (typically around 30-40 ft-lbs).

4. Reconnect Battery and Verify

• Reconnect the negative battery terminal.
• Clear any stored error codes using the OBD-II scanner.
• Start the engine and allow it to reach operating temperature.