how to fix P0700 transmission code on Toyota Highlander XU70 (2020-Present)

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the engine is off.
• Disconnect the battery to prevent electrical shorts.

2. Fluid Check and Replacement

• Sub-steps:
  1. Locate the transmission dipstick (if equipped) or the fill plug.
  2. Remove the dipstick or fill plug and check the fluid level.
  3. If fluid is low, add the recommended transmission fluid (Toyota ATF WS).
  4. If the fluid is dirty or burnt, drain the transmission fluid by removing the drain plug or pan.
  5. Replace the old fluid with fresh Toyota ATF WS fluid and recheck the level.

3. Inspect and Repair Wiring

• Sub-steps:
  1. Inspect the wiring harness and connectors going to the TCM and transmission.
  2. Repair or replace any damaged wires or connectors.
  3. Ensure all connections are secure.

4. Replace Transmission Control Module (if necessary)

• Sub-steps:
  1. Locate the TCM, usually found near the transmission or under the dashboard.
  2. Disconnect the wiring harness from the TCM.
  3. Remove the mounting bolts holding the TCM in place.
  4. Install the new TCM, securing it with bolts and reconnecting the harness.
  5. Reconnect the battery.