how to fix P0730 incorrect gear ratio in BMW X5 G05 (2019-2024)

Solution

1. Preparation

• Gather necessary tools and parts.
• Park the vehicle on a level surface and engage the parking brake.
• Disconnect the battery to ensure safety while working on electrical components.

2. Inspect and Replace Transmission Fluid

• Sub-steps:
  1. Locate the transmission fluid dipstick and remove it.
  2. Check the fluid level; if low, fill with manufacturer-recommended ATF (usually Dexron VI or equivalent).
  3. If the fluid is dirty or burnt, proceed to drain and replace it.
  4. To drain, locate the transmission drain plug, remove it, and allow the fluid to fully drain into a catch pan.
  5. Replace the drain plug and torque to the manufacturer's specifications (typically around 8-10 Nm).
  6. Refill the transmission with new fluid through the dipstick tube until the correct level is reached.

3. Inspect Wiring and Connectors

• Sub-steps:
  1. Visually inspect the transmission wiring harness for frays, cuts, or signs of overheating.
  2. Disconnect and clean the electrical connectors to the TCM and transmission solenoids.
  3. Use a multimeter to test for continuity in the wiring.

4. Test Drive and Monitor

• Sub-steps:
  1. Reconnect the battery.
  2. Start the engine and allow it to reach operating temperature.
  3. Perform a test drive under various driving conditions to assess shifting behavior.
  4. Monitor the transmission performance and check for any new error codes.