my Toyota Highlander Third Generation (2014-2019) has a check engine light and a P0700 code what doe...

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Ensure the vehicle is parked on a level surface with the parking brake engaged.
• Disconnect the battery to ensure safety while working on electrical components.

2. Inspect and Replace Transmission Fluid

• Tools Required: Socket set, funnel, transmission fluid.
• Check the transmission fluid level using the dipstick.
• If low, add the recommended type of transmission fluid (typically Toyota ATF WS).
• If the fluid is dark or has a burnt smell, consider a transmission fluid change.
• To change, drain the old fluid by removing the transmission pan, replace the filter, and refill with new fluid.

3. Check and Repair Wiring/Connectors

• Tools Required: Multimeter, wire brush, electrical tape.
• Inspect the wiring harness and connectors leading to the TCM for any frays, corrosion, or loose connections.
• Clean any corroded connections with a wire brush and ensure they are tightly seated.
• Repair any damaged wiring by splicing in new wire or replacing connectors as necessary.

4. Test and Replace Transmission Control Module (if necessary)

• Tools Required: Multimeter, replacement TCM.
• Connect the multimeter to the TCM as per manufacturer specifications and test for appropriate voltage and continuity.
• If the TCM is found to be faulty, remove the old module (typically secured with bolts or clips) and install the new one, ensuring all connectors are properly reattached.