how to diagnose P0700 code in Toyota Highlander XU70 (2020-Present)

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the battery to ensure safety while working on electrical components.

2. Check and Replace Transmission Fluid

• Sub-steps:
  1. Locate the transmission dipstick and pull it out.
  2. Wipe clean and reinsert to check the fluid level.
  3. If low, add the recommended ATF (Automatic Transmission Fluid) type (usually Toyota WS).
  4. If fluid is dirty or burnt, drain and replace the fluid.
• Tools Required: Transmission funnel, fluid pump.

3. Inspect and Repair Wiring/Connectors

• Sub-steps:
  1. Locate the TCM and inspect the harness for any signs of wear or damage.
  2. Clean the connectors with electrical contact cleaner.
  3. Repair or replace any damaged wires.
• Tools Required: Electrical contact cleaner, wire repair kit.

4. Replace Transmission Control Module (if necessary)

• Sub-steps:
  1. Remove any components obstructing access to the TCM.
  2. Unplug the TCM connector and remove the mounting bolts.
  3. Install the new TCM and secure it with bolts.
  4. Reconnect the wiring harness.
• Tools Required: Socket set, screwdrivers.