2016-2019 BMW 750e xDrive Rear Electronic Module: Decoding Failures and Programming

What is the Remote Power Distribution Module (REM)?

The Remote Power Distribution Module, or Rear Electronic Module (REM), is a crucial computer in your 2016-2019 BMW 750e xDrive. Think of it as a dedicated control center for all the electronic accessories and systems located in the rear of the vehicle. It takes your commands—like pressing the trunk release or activating a turn signal—and tells the corresponding part what to do. This module is responsible for operating the tail lights, brake lights, reverse lights, license plate lights, trunk lock, and sometimes interacts with the fuel pump and rear window systems. Because it controls so many different components, its failure can lead to a variety of strange and frustrating electrical symptoms.

Symptoms of a Failing REM

A faulty REM can make it seem like multiple unrelated parts have failed at once. The issue often isn't with the lights or locks themselves, but with the module that controls them. Watch for these common signs:

• Rear Light Malfunctions: One or more tail lights, brake lights, or turn signals may stop working, flicker, or stay on constantly.
• Trunk Release Failure: The electronic trunk latch may stop responding to the key fob or interior release button.
• Inoperative Rear Windows or Defroster: The module may fail to power the rear window motors or the defroster grid.
• "Key Not Detected" Warnings: Issues with the Comfort Access system can sometimes be linked to a faulty REM, as it's part of the vehicle's complex electronic network.
• Multiple Warning Lights: You may see various check control messages on the dashboard related to lighting and other rear-body systems.
• Complete Communication Loss: In severe cases, a diagnostic tool will be unable to communicate with the REM, indicating a total failure.

Common Diagnostic Trouble Codes (DTCs)

A professional scan tool may reveal specific fault codes pointing directly to an REM failure. These codes are strong indicators that the module itself is the problem.

Known Issues: Water Intrusion

One of the most common causes of REM failure in the G12 7-Series platform is water damage. The module is located in the trunk area, typically on the right side, which is vulnerable to moisture. Water can enter the trunk from several sources:

• Clogged Sunroof Drains: Drains that run from the sunroof down through the body of the car can become clogged with debris, causing water to overflow into the trunk.
• Failed Trunk Lid Seals: Aged or damaged rubber seals around the trunk opening can allow rainwater to seep in.
• Leaking Tail Light Gaskets: The seals around the tail light assemblies can degrade over time, letting water drip behind the trunk liner and onto electronic modules.

Buying a Used Remote Power Distribution Module

A used OEM module is an excellent, cost-effective alternative to a brand-new part, but careful purchasing is key. Because this is a sensitive electronic component, here’s what to look for:

• Verify the Part Number: Match the part number from your original module exactly. The numbers 9353742 and 61149353742 are common for the junction terminal associated with the REM on this platform. Using the wrong part number can lead to incompatibility, even if it looks identical.
• Inspect for Corrosion: Carefully examine the electrical connector pins on the used module. Any signs of green or white crusty residue indicate corrosion from moisture, and the part should be avoided.
• Check the Casing for Water Marks: Look for any discoloration or stains on the plastic housing. This can be a sign that the module was exposed to water in the donor vehicle.
• Buy from Reputable Sellers: Purchase from established sellers who offer a warranty and a clear return policy. This protects you if you receive a defective part.

Programming is Mandatory: What You Need to Know

You cannot simply swap a new or used REM into your 750e and expect it to work. The module must be programmed (also called coding or flashing) to match your car's specific features and Vehicle Identification Number (VIN).

• Why is programming required? The REM needs to know the exact configuration of your car. For example, it needs to know if you have standard tail lights or optional LED lights, a power trunk, etc. Without programming, these features will not work correctly.
• Who can program the module?
  • BMW Dealerships: They have the factory tools and can always perform the programming.
  • Independent BMW Specialists: Many independent shops that specialize in BMWs have the necessary diagnostic tools, like ISTA or Autologic, to program a replacement REM.
  • Remote Coding Services: Some companies offer remote programming services where a technician can code the module for you over the internet using a specific cable (ENET cable) and a laptop.

A general mechanic or a locksmith typically does not have the expensive, brand-specific software required for this job. You must confirm your chosen installer can perform BMW module programming before starting the repair.

Cost of Replacement

The total cost can vary significantly based on whether you use new or used parts and the labor rates in your area.

Frequently Asked Questions (FAQ)