my BMW X3 F25 (2011-2018) has no power to the rear wheels when accelerating

Solution

1. Preparation

• Gather all tools and parts needed for the repair.
• Disconnect the battery to ensure safety while working on electrical components.

2. Inspect Transfer Case

• Tools Required: Socket set, torque wrench
• Sub-steps:
  1. Remove the transfer case inspection cover (if applicable) using a socket set.
  2. Check for fluid leaks around the seals and inspect the fluid level; top off or replace fluid if low or contaminated.
  3. Inspect the transfer case for any internal damage by rotating the input shaft and listening for abnormal noises.

3. Inspect Driveshaft and Rear Differential

• Tools Required: Jack stands, socket set
• Sub-steps:
  1. Lift the rear of the vehicle securely on jack stands.
  2. Inspect the driveshaft for any signs of wear, such as cracks or play at the universal joints.
  3. Remove the rear differential cover and check the fluid level; replace it if it's low or contaminated.
  4. Inspect the ring and pinion gears for damage or excessive wear.

4. Check Wheel Speed Sensors

• Tools Required: Multimeter, socket set
• Sub-steps:
  1. Disconnect the electrical connectors from the rear wheel speed sensors.
  2. Use a multimeter to check for continuity and resistance; compare readings to manufacturer specifications.
  3. Replace any faulty sensors with new ones.

5. Transmission Fluid Check

• Tools Required: Transmission fluid dipstick (if applicable), funnel
• Sub-steps:
  1. Locate the transmission dipstick and remove it to check fluid level and condition.
  2. If the fluid is low, add the appropriate type of transmission fluid as per the manufacturer's specifications.
  3. If the fluid is burnt or contaminated, perform a transmission fluid change.