how to fix P0700 transmission code in Toyota Highlander Fourth Generation (2020-present)

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the battery to prevent electrical shock.
• Ensure the vehicle is on a level surface and secured with wheel chocks.

2. Transmission Fluid Replacement

• Sub-steps:
  1. Remove the transmission fluid drain plug using a socket set and let the old fluid drain into a container.
  2. Replace the drain plug and tighten to the manufacturer’s torque specifications.
  3. Remove the transmission fluid fill plug and add new ATF (Automatic Transmission Fluid) that meets Toyota specifications using a funnel.
  4. Start the engine and let it warm up, then cycle through the gears to ensure fluid circulates.
  5. Check fluid level again and top off if necessary.

3. Wiring and Connector Inspection

• Sub-steps:
  1. Locate the TCM connector (refer to service manual for exact location).
  2. Disconnect the TCM connector and inspect for bent pins or corrosion.
  3. Clean the connector with electrical contact cleaner if necessary.
  4. Reconnect the TCM and ensure a secure fit.

4. TCM Testing and Replacement (if necessary)

• Sub-steps:
  1. Using a multimeter, measure the voltage at the TCM connectors while the ignition is on. Compare readings to specifications in the service manual.
  2. If readings are out of spec, replace the TCM. To replace, remove the mounting screws, disconnect the harness, and install the new TCM securely.
  3. Reconnect the battery after all repairs are completed.