how to diagnose P0700 code in Toyota Highlander Third Generation (2014-2019)

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 before working on electrical systems.

2. Check Transmission Fluid

• Tools Required: Transmission dipstick, clean cloth.
• Remove the transmission dipstick and wipe it clean.
• Reinsert the dipstick and remove it again; check the fluid level.
• If low, add the recommended type of transmission fluid (e.g., Toyota ATF WS).
• Inspect the fluid for a burnt smell or dark color; if found, a fluid change may be necessary.

3. Inspect Wiring and Connectors

• Tools Required: Visual inspection tools, multimeter.
• Visually inspect the wiring harness and connectors leading to the TCM for any signs of wear or damage.
• Use the multimeter to check for continuity in the wires. Repair or replace damaged wiring as necessary.

4. Test Transmission Control Module

• Tools Required: Multimeter, OBD-II scanner.
• Ensure the TCM is receiving the correct voltage as specified by the manufacturer.
• If voltage is correct, check the output signals from the TCM to the transmission solenoids.
• If the TCM is not functioning properly, it may need to be replaced.

5. Clear Codes and Test Drive

• Tools Required: OBD-II scanner.
• Clear the P0700 code using the OBD-II scanner.
• Test drive the vehicle to see if the code returns and monitor transmission performance.