how to fix P0700 code in BMW 3 Series G20/G21 (2019-2024)

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the engine is turned off.
• Disconnect the battery to prevent electrical shorts.

2. Inspect and Replace Transmission Fluid

• Tools Required: Transmission fluid pump, socket set, drain pan.
• Remove the transmission drain plug and drain old fluid into a pan.
• Inspect the old fluid for contamination; if it appears burnt or has metal shavings, further inspection of the transmission is warranted.
• Replace with manufacturer-recommended transmission fluid.
• Reinstall the drain plug and torque to specifications.

3. Inspect and Repair Wiring

• Tools Required: Multimeter, electrical connectors.
• Visually inspect the wiring harness to the TCM for any signs of wear or damage.
• Use a multimeter to check for continuity and proper voltage in the harness.
• Repair or replace any damaged wires or connectors.

4. Replace TCM (if necessary)

• Tools Required: Socket set, torque wrench.
• Remove the mounting bolts securing the TCM.
• Disconnect the electrical connectors from the TCM.
• Install the new TCM by reversing the removal steps, ensuring all connectors are securely attached.
• Torque the mounting bolts to manufacturer specifications.

5. Reconnect Battery and Clear Codes

• Reconnect the battery terminals.
• Use an OBD-II scanner to clear the P0700 code and any other related transmission codes.