how to diagnose P0700 transmission code on my Volkswagen Golf MK7.5 (2020-Present)?

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the parking brake is engaged.
• Disconnect the battery to avoid any electrical issues during the repair.

2. Inspect Transmission Fluid

• Locate the transmission dipstick (if applicable) and remove it.
• Wipe the dipstick clean and reinsert it to check the fluid level; add fluid if low.
• If the fluid is dark or has a burnt odor, perform a transmission fluid change.

3. Repair or Replace Damaged Wiring

• Visually inspect the wiring harness connected to the TCM.
• If damaged, cut out the damaged section and splice in new wiring of the same gauge.
• Use heat-shrink tubing and electrical tape to secure the connections.

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

• Remove the TCM by unscrewing the mounting bolts and disconnecting the electrical connectors.
• If the TCM is faulty, replace it with a new unit.
• Reinstall the new TCM and secure it with bolts and connectors.

5. Reconnect Battery and Test Drive

• Reconnect the battery.
• Start the vehicle and allow it to reach operating temperature.
• Conduct a test drive, monitoring for any transmission issues or return of the P0700 code.