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

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

Solution

1. Preparation

• Ensure the vehicle is parked on a level surface and the ignition is turned off.
• Gather all necessary tools and parts before beginning the repair.

2. Transmission Fluid Inspection and Replacement

• Tools Required: Transmission fluid pump, socket set, fluid catch pan.
• Sub-steps:
  1. Remove the transmission fluid dipstick and check fluid level.
  2. If the fluid is low, locate the transmission fluid fill plug and add the recommended fluid type (usually VW ATF).
  3. If the fluid is dark or has a burnt smell, drain the fluid by removing the drain plug and allow it to completely empty into the catch pan.
  4. Replace the drain plug with a new gasket and torque it to the manufacturer’s specifications.
  5. Refill the transmission with fresh, manufacturer-recommended fluid using the fluid pump.

3. Wiring and Connector Inspection

• Tools Required: Multimeter, wire brush.
• Sub-steps:
  1. Disconnect the battery to prevent electrical shorts.
  2. Locate the TCM and visually inspect the wiring harness and connectors for damage or corrosion.
  3. Clean any corrosion from connectors using a wire brush.
  4. Use a multimeter to test for continuity in the wiring to ensure there are no breaks.

4. TCM Replacement (if necessary)

• Tools Required: Socket set, torque wrench.
• Sub-steps:
  1. Disconnect the battery again and remove any covers obstructing access to the TCM.
  2. Unplug the TCM connector and remove the mounting screws.
  3. Install the new TCM by reversing the removal steps, ensuring to torque screws to specifications.
  4. Reconnect the battery.