how to fix P0700 code in BMW 3 Series E90/E91 (2005-2012)

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the negative battery terminal to ensure safety while working on the vehicle.

2. Fluid Change

• Sub-steps:
  1. Raise the vehicle securely on jack stands.
  2. Place a drain pan under the transmission pan.
  3. Remove the transmission pan bolts with a socket set and carefully lower the pan.
  4. Drain the old fluid completely and inspect the magnet for metal shavings indicating wear.
  5. Replace the transmission filter if applicable.
  6. Reinstall the transmission pan with a new gasket and torque the bolts to the manufacturer's specifications (typically around 8 Nm).
  7. Fill the transmission with the appropriate type and amount of fluid (usually BMW ATF, check specifications).

3. Wiring and Connector Inspection

• Sub-steps:
  1. Visually inspect the wiring harness and connectors for the TCM and solenoids.
  2. Clean any corrosion from connectors and ensure a tight connection.
  3. Repair or replace damaged wiring as needed.

4. TCM Testing and Replacement (if necessary)

• Sub-steps:
  1. Using a multimeter, check the voltage at the TCM connectors while the ignition is on.
  2. If voltage is absent, trace back to find the fault in the wiring.
  3. If the TCM is faulty, remove it by unscrewing the mounting bolts and disconnecting the harness.
  4. Install a new TCM by reversing the removal steps and ensuring proper connection.