how to fix P0700 code in Volkswagen Passat B8 (2015-2022)

Learn how to diagnose and fix P0700 transmission issues in Volkswagen Passat B8 (2015-2022). Step-by-step guide with diagnostic procedures and repair instructions.

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, multimeter, torque wrench, fluid catch pan
• Ensure the vehicle is on a level surface and the engine is off. Disconnect the battery to prevent any electrical shorts.

2. Check and Replace Transmission Fluid

• Sub-steps:
  1. Locate the transmission dipstick or fill plug.
  2. Remove the dipstick or fill plug and check fluid level using the dipstick.
  3. If fluid is low, add the correct type of transmission fluid as specified in the owner’s manual.
  4. If fluid is dirty or burnt, drain the transmission fluid using a catch pan, replace the filter, and refill with new fluid.
  5. Torque the drain plug to the manufacturer’s specifications.

3. Repair or Replace Wiring and Connectors

• Sub-steps:
  1. Inspect the wiring harness leading to the TCM for any damage or corrosion.
  2. If damage is found, splice in new wire sections or replace the entire harness as necessary.
  3. Clean any corroded connectors using electrical contact cleaner and reconnect securely.

4. TCM Replacement (if necessary)

• Sub-steps:
  1. Locate the TCM, which is typically found near the transmission.
  2. Disconnect the electrical connectors carefully.
  3. Remove the TCM mounting bolts using a socket set and remove the TCM.
  4. Install the new TCM, ensuring it is mounted securely and reconnect all electrical connectors.
  5. Reconnect the battery.