E39 Top — Schema Electrique Bmw

Finding the right schéma électrique (wiring diagram) for a

is essential for fixing "electrical gremlins" that often plague this modern classic. Most owners rely on the BMW WDS (Wiring Diagram System), which was originally a browser-based tool but has been mirrored by community sites like BMW-Planet to work on modern systems. Common Electrical Hotspots

If you're chasing a specific problem, these areas are the most frequent culprits in the E39:

The "Water Problem" (Passenger Floor): A major cause of total electrical failure is water leaking into the passenger side footwell. Beneath the carpet sits a power distribution block that corrodes, cutting power to seats, windows, and the heater.

Power Seats: The power seat switches are notorious for failing or having corroded pins. You can test the DC reversible motors by checking for battery voltage between specific pins (e.g., pin 5 for power and pin 6 for ground).

Blower Motor & FSU: If your climate control is acting up, the Final Stage Unit (FSU) or "sword" is likely the issue. Accessing it requires disassembling parts of the lower dashboard and glove box area.

The I-Bus/CAN Bus: The E39 uses a complex digital communication network. A single failing module (like a radio or PDC unit) can "clog" the bus and cause unrelated symptoms like flickering dash lights or non-working steering wheel buttons. Essential Diagnostic Resources BMW E39 5 Series Blower Motor and FSU Replacement DIY

While the BMW E39 was never produced as a factory convertible (it was only available as a sedan or touring/wagon), owners seeking electrical guides for "top" systems typically refer to the sunroof (moonroof) or are searching for technical data from related models like the E36 or E46. Electrical Schema Overview for E39 Roof Systems

For the standard E39, the roof electrical system is centered on the sunroof module and the General Module (GMIII).

Main Components: The system includes the sunroof motor, a position-sensing potentiometer, and the roof switch. schema electrique bmw e39 top

Wiring Color Codes: Common BMW coding includes Red for power supply, Black for ground, Green for signals, and Blue for data lines.

Control Unit: The General Module (GM) manages comfort features, including the "one-touch" opening and anti-trap functions of the roof. Troubleshooting & Diagnostics

If you are experiencing issues with the roof mechanism, follow these standard diagnostic steps:

Check Fuses: For the E39, primary roof-related fuses are often located in the glove box or above the battery in the trunk. A blown fuse can cause the system to become completely unresponsive.

Manual Overide: If the electrical system fails, there is an emergency manual operation point. On the E39, you can remove the roof switch panel to access a hex-head bolt on the motor, allowing you to close the roof manually with a 4 mm hex tool.

Reset/Initialization: If the "one-touch" feature fails, you can often reset the module by holding the roof switch in the "tilt" position for 15–30 seconds until the mechanism cycles completely.

Wiring Inspection: Check for broken wires in the harness, especially near hinges or moving parts. A broken signal wire (often brown/white) is a common cause for the module losing track of the roof's position. Resources for Full Schematics

For detailed pinouts and full circuit diagrams, the most authoritative sources are:

BMW WDS (Wiring Diagram System): This is the official dealer-level software used for interactive schematics. Finding the right schéma électrique (wiring diagram) for

Bentley Publishers: Their E39 Service Manual is the "gold standard" for physical wiring diagrams and repair steps.

Community PDF Repositories: Sites like Scribd and Manuals.plus host community-shared wiring diagrams for various E39 systems. Convertible roof not opening

Le système électrique de la BMW Série 5 (E39) est réputé pour sa complexité, mais il suit une structure logique répartie sur plusieurs zones du véhicule. Pour diagnostiquer ou modifier votre E39, il est essentiel de localiser les principaux boîtiers de fusibles et modules de commande. Localisation des Boîtiers de Fusibles et Relais

La E39 ne possède pas un, mais jusqu'à six emplacements distincts pour les fusibles et relais :

Boîte à gants (Haut) : C'est l'emplacement principal pour les accessoires intérieurs (fusibles F1 à F45). Vous y trouverez également un carton de correspondance indiquant l'ampérage et la fonction de chaque fusible.

Compartiment moteur (E-Box) : Situé sous le filtre d'habitacle côté passager, ce boîtier abrite les fusibles critiques pour la gestion moteur (DME), les injecteurs et les capteurs d'arbre à cames (fusibles EF1 à EF5).

Coffre (Côté droit) : Directement au-dessus de la batterie, cette zone protège le verrouillage centralisé, le dégivrage arrière et la pompe à essence (modèles avant 2001).

Sous le siège passager (Plancher) : Un boîtier "caché" sous la moquette contient des fusibles de forte puissance (50A à 80A) pour l'ABS, le contacteur d'allumage et le module d'éclairage (LCM). Composants Électriques Majeurs

Module d'Éclairage (LCM) : Situé derrière la garniture du pied de porte côté passager, il gère tous les feux extérieurs et peut causer des problèmes de phares restant allumés s'il est défectueux. Convertible Top Motor : This is the actuator

Module Général (GM3) : Placé derrière la boîte à gants, il contrôle le verrouillage, les vitres électriques et l'essuie-glace.

Prise Diagnostic OBD2 : Sur les phases 2, elle se situe sous le tableau de bord, à droite de la colonne de direction. Conseils de Lecture du Schéma

3. WDS (Wiring Diagram System) – Online or Downloadable

BMW's WDS is a Java-based interactive application. You can click a component (e.g., "Left low beam headlight") and the software highlights the entire circuit, including all connectors and splices in between. Many vintage BMW forums offer downloadable versions of WDS v12.0 or v14.0.

Overview of the Convertible Top System

The convertible top system in the BMW E39 is controlled electronically, ensuring ease of use and reliability. The main components include:

  • Convertible Top Motor: This is the actuator that moves the top up and down.
  • Convertible Top Control Module (TCM): Often integrated with the car's main computer (DME/DEI), it controls the operation of the top.
  • Soft Top Latch and Locking Mechanism: Mechanical parts that secure the top in place when closed.
  • Sensors and Switches: Various inputs to the control module, such as the top's position, latch status, and ignition switch.

2. Brake Light / Tail Light Failures (LCM Issues)

Symptoms: "Brake light circuit failure" on dash, but bulbs are fine.
Top Schematic Insight: The LCM measures resistance across the brake light bulbs (via wire SW/RT). If the trunk wiring harness (between body and trunk lid) cracks, you get intermittent shorts. The diagram shows the exact splice point X277 inside the trunk hinge boot.

1. Power Distribution (Front and Rear Power Boxes)

The E39 has two main fuse boxes:

  • Front Power Box (E-box): Under the hood, passenger side. Contains main relays (DME main relay, fuel pump relay, horn relay).
  • Rear Power Box (Glovebox/Fuse Panel): Behind the glovebox. Contains fuses F1 to F75.

A top diagram will show the exact path from the battery (located in the trunk) through the B+ terminal, to the ignition switch, and then to these distribution boxes.

The #1 "Top" Feature: Full, Interactive Color-Coded System with Component Location

A standard black & white wiring diagram is basic. A "top" schema for the E39 has these specific high-end features:

  1. Full Color by Wire Function:
    • Red: Constant power (B+)
    • Green: Ignition-switched power (Terminal 15)
    • Violet/Blue: Convenience/lighting circuits
    • Brown: Chassis grounds
    • Yellow/White: Signal/data bus lines (especially for P-bus, I-bus, and K-bus)
  2. Splice (S) and Connector (X) Index: A searchable table of every inline splice (e.g., S202 is power to the LCM) and every multi-pin connector (e.g., X6000 at the instrument cluster).
  3. Module Internal Schematics: Details inside the LCM (Light Check Module), GM (General Module), and ABS/DSC unit – not just external pinouts.
  4. Bus Topology Map: A clear diagram showing how the I-bus (body), K-bus (body, slower), P-bus (diagnostic), and M-bus (mirrors/seats) connect between the 20+ modules (DME, EWS, LCM, GM, IKE, MID, PDC, etc.).
  5. Wire Gauge & Color Code Legend: Exact metric wire sizes (e.g., 0.5 mm², 2.5 mm² RT/WS = red/white).