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

Solution

1. Preparation

• Tools Required: OBD-II scanner, multimeter, socket set, torque wrench, transmission fluid, funnel, safety gloves, safety glasses.
• Safety Warnings: Disconnect the battery before working on electrical systems. Allow the engine to cool before draining transmission fluid.

2. Check and Replace Transmission Fluid

• Sub-steps:
  1. Locate the transmission fluid dipstick or fill plug and remove it.
  2. Check fluid level: If low, add the specific type of transmission fluid recommended by the manufacturer (consult the owner’s manual).
  3. If fluid is burnt or contaminated, drain the transmission fluid using a drain pan.
  4. Replace with new fluid: Refill with the appropriate fluid type until it reaches the proper level.
  5. Recheck the level after running the engine for a few minutes.

3. Inspect and Repair Wiring and Connectors

• Sub-steps:
  1. Visually inspect the wiring harness connected to the TCM and transmission solenoids for frayed wires or corrosion.
  2. Repair or replace any damaged wiring as necessary.
  3. Reconnect all connectors securely.

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

• Sub-steps:
  1. Test the TCM with a multimeter to ensure it is functioning correctly.
  2. If the TCM is faulty, remove it by disconnecting the connectors and unscrewing it from its mounting location.
  3. Install the new TCM by reversing the removal steps and ensuring it is securely mounted.
  4. Reprogram the TCM if needed, following manufacturer guidelines.

5. Test Drive and Monitor

• Sub-steps:
  1. Reconnect the battery and clear any stored codes using the OBD-II scanner.
  2. Start the engine and allow it to warm up.
  3. Test drive the vehicle to ensure smooth shifting and that the check engine light does not reappear.