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

Solution

1. Preparation

• Gather tools: OBD-II scanner, multimeter, socket set, torque wrench, transmission fluid, and cleaning supplies.
• Ensure the vehicle is parked on a flat surface and the engine is turned off.

2. Inspect and Change Transmission Fluid

• Sub-steps:
  1. Raise the vehicle using jack stands for safety.
  2. Locate the transmission fluid dipstick or fill plug.
  3. Remove the dipstick or fill plug and check fluid level; add fluid if low.
  4. Inspect the fluid for discoloration or a burnt smell; if degraded, proceed to change the fluid.
  5. Drain the old transmission fluid using a drain pan by removing the drain plug.
  6. Replace the transmission filter (if applicable) by removing the transmission pan.
  7. Reinstall the pan with a new gasket and torque bolts to manufacturer specifications.
  8. Fill the transmission with fresh fluid through the dipstick or fill plug to the correct level.

3. Repair or Replace TCM

• Sub-steps:
  1. Disconnect the battery to ensure safety while working on electrical components.
  2. Locate the TCM, typically found near the transmission or under the dashboard.
  3. Remove the TCM connector by pressing the release tab and pulling it out.
  4. If testing, use a multimeter to check for proper voltage and continuity at the connector pins.
  5. If faulty, replace the TCM with a new or refurbished unit, ensuring compatibility with the vehicle’s VIN.
  6. Reconnect the TCM and battery.