my Genesis G70 IG (2017-2023) has a check engine light with code P0780

Learn how to diagnose and fix P0780 transmission issues in Genesis G70 (2017-2023). Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Ensure the vehicle is parked on a level surface and secure with wheel chocks.
• Disconnect the battery to prevent electrical shorts.

2. Inspect and Replace Transmission Fluid

• Tools Required: Transmission fluid pump, fluid catch pan, socket set, funnel.
• Check the fluid level using the dipstick; add fluid if low.
• If fluid is dark or burnt, drain the transmission fluid:
  1. Remove the transmission pan bolts using a socket set.
  2. Carefully lower the pan and allow fluid to drain completely into the catch pan.
  3. Replace the transmission filter if applicable.
  4. Reattach the pan with new gasket material, tightening bolts to manufacturer specifications (typically around 9-12 ft-lbs).
  5. Refill the transmission with the correct type of fluid (consult the owner’s manual for specifications).

3. Inspect and Repair Electrical Connections

• Tools Required: Multimeter, dielectric grease.
• Inspect the TCM connectors:
  1. Remove the TCM from its mounting location.
  2. Clean the connectors with electrical cleaner.
  3. Use a multimeter to check for continuity in the wiring harness.
  4. Apply dielectric grease to the connectors before reinstallation to prevent future corrosion.

4. Reconnect Battery and Clear Codes

• Reconnect the battery terminals securely.
• Use the OBD-II scanner to clear the check engine codes and reset the system.

5. Road Test

• Drive the vehicle under various conditions to ensure that the transmission shifts smoothly and the check engine light does not reappear.