General Electrical System - Service Techniques: Overview BMW X6 E71

Scheme 1160

Brief description of components

The following components deliver signals for the digital compass

1. Magnetic field sensor up to 09/2006 The magnetic field sensor is installed in the mirror base. The magnetic field sensor measures the current alignment of the magnetic field. The signal is sent to the control electronics for the compass in the interior mirror. from 09/2006 The magnetic field sensor is on the PCB in the interior mirror.
2. Control electronics for the compass The interior mirror is electrically connected to the roof control panel (FZD). The control electronics for the compass are integrated into the board for the interior mirror. The signals from the magnetic field sensor are received by the control electronics. The LCD display is activated directly by the control electronics.

The following components are controlled

1. Display in interior mirror up to 09/2006 The LC display (window) is situated at top right in the interior mirror. The points of the compass are presented digitally on the LCD display (LCD: Liquid Crystal Display). The display is divided into eight compass points. from 09/2006 The point of the compass is displayed in transparent light technology in the interior mirror as well. The display is also at the top right in the interior mirror. The display is divided into eight compass points.

The junction box consists of the distribution box and the junction box electronics.

1. JBE: Junction box electronics The junction box electronics unit combines numerous functions in a single control unit. The junction box electronics unit is connected via 4 plug connections. A 54-pin connector connects the instrument panel. Two further connectors are for the connection on the main wiring harness. These connectors are 54-pin and 47-pin. A 23-pin internal connection directly connects the junction box electronics to the power distributor.
2. Electrical distributors The fuses and various plug-in relays are located in the junction box distribution box. The boards in the distribution box are connected to various relays, depending on the equipment specification. There is an opening in the lower section of the junction box. The junction box electronics unit is connected with the distribution box through this opening.

Note. For current details about the pin assignment and fuse assignment of the junction box electronics and the power distributor, please refer to the BMW diagnosis system

Different versions of the power distributor are fitted, depending on the model series and Model Year measures. For example, the complete fuse assignment may change as part of Model Year measures.

1. 03/2007 Model Year measure (not E70, E71): primarily changes to pin assignment
2. 09/2007 Model Year measure (not E70, E71): primarily changes to fuse assignment

Depending on the vehicle equipment, various relays are mounted on the boards in the power distributor.

The steering column switch cluster (SZL) is connected to the vehicle wiring harness via 2 plug connectors.

The steering column switch cluster consists of the following components

1. Evaluation electronics The evaluation electronics analyze the signals from the components and send them as CAN messages on the F-CAN. The evaluation electronics include the following components: Microprocessor Power supply F-CAN connection Interfaces for optical and electrical input signals
2. Steering-angle sensor The steering-angle sensor optically detects the steering angle turned at the steering wheel by means of an encoded disc. The data is read and analyzed by the evaluation electronics. The data is transmitted directly to the DSC via the F-CAN. (F-CAN = Chassis CAN; DSC = Dynamic Stability Control.) Signal path: SZL -> F-CAN -> DSC
3. Steering column stalk The lever positions of all steering column stalks are optically monitored. The actions of pressing the buttons, turning the thumbwheels and pressing the rocker switches are detected by switching mats. The switching mats forward the position of the buttons and thumbwheels as voltage signals. Depending on the vehicle's equipment, the steering column switch cluster (SZL) could have the following steering column stalks: Wiper/washer switch The switch signals are read into the steering column switch cluster where they are evaluated. The evaluated switch signals are emitted onto the F-CAN as a CAN message (It is only possible to check the switch positions with the BMW diagnosis system via DSC as the steering column switch cluster is not directly connected to the diagnosis system). Cruise-control system steering column stalk The switch signals are read into the steering column switch cluster where they are evaluated. The evaluated switch signals are emitted onto the F-CAN as a CAN message (It is only possible to check the switch positions with the BMW diagnosis system via DSC as the steering column switch cluster is not directly connected to the diagnosis system). Turn-signal/main-beam switch The switch signals are read into the steering column switch cluster where they are evaluated. The evaluated switch signals are resistance-encoded and transmitted from the steering column switch cluster by direct wires to the FRM (footwell module). The signals for the on-board computer functions are transmitted by a direct wire to the instrument cluster (KOMBI).
4. Coil spring cassette The coil spring cassette has the task of transferring electrical signals to or from the steering wheel. The signals are transferred as follows: Airbag unit (signals to steering wheel) Signal path: MRS control unit -> SZL (signal simply looped through) -> Coil spring -> Airbag unit Horn (signal from steering wheel) Signal path: Horn switch -> SZL (signal simply looped through) -> Junction box Multifunction buttons (signal from steering wheel) Signal path: Multifunction buttons -> SZL -> F-CAN -> Junction box electronics (signal simply looped through) -> F-CAN -> DSC control unit (serves as gateway) -> PT-CAN -> Junction box electronics (serves as gateway) -> K-CAN -> Audio system (check switch positions with BMW diagnostic system using DSC)

The control units involved in the functions of the steering column switch cluster are as follows

1. DSC: Dynamic Stability Control The steering column switch cluster (SZL) does not have its own fault memory. All fault data for the steering column switch cluster are stored in the DSC control unit. The DSC is connected to the steering column switch cluster via the F-CAN (chassis CAN).
2. JBE: Junction box electronics The junction box electronics unit is the data interface (= gateway) between the K-CAN and the PT-CAN. (K-CAN = Body CAN; PT-CAN = Powertrain CAN). Signals from the F-CAN (Chassis CAN) are simply looped through. This means: Signals from the F-CAN are not received or evaluated by the junction box electronics. The F-CAN cables are simply routed through the junction box housing. The junction box consists of the junction box electronics and the electrical distribution center.
3. FRM: Footwell module The footwell module controls the vehicle lighting. The footwell module is connected to the steering column switch cluster (SZL) by direct wires.
4. CAS: Car Access System The Care Access System reactivates the control units on the PT-CAN via the wake-up wire (terminal 15 wake-up).
5. KOMBI: Instrument cluster Information on the on-board computer functions can be called up via the on-board computer button (BC button) and the rocker switch. (The BC button and the rocker switch are integrated into the turn-signal/main-beam switch). The contents are displayed in the LCD display in the instrument cluster. The signals for the on-board computer functions are transmitted by a direct wire from the SZL to the instrument cluster.

The following components supply signals for the footwell module

1. Ride-height sensors
2. Reversing light switch
3. Brake light switch
4. Hazard warning lights switch
5. Light switch
6. Driver's door switch block
7. Door contacts in rear doors
8. Door contacts in front doors
9. Driver's door lock

Several control units are involved in the lighting: In a stricter sense, the following control unit are involved in the lighting system (in alphabetical order)

1. ACSM/MRS: Crash safety module/multiple-restraint system E81, E82, E87, E90, E91, E92: Multiple restraint system E70, E71, E93: (ACSM stands for "Advanced Crash Safety Module", also known as the crash safety module) The footwell module is connected to the crash safety module/MRS control unit via the K-CAN. In the event of an accident with corresponding severity, the footwell module automatically switches on the interior light hazard warning lights. E92 The crash safety module transmits a message about the status of the front-passenger seat-occupancy detector on the K-CAN. The belt feeder on the front-passenger side is only actuated if the front-passenger seat is occupied.
2. AHM: Trailer module The trailer module sends a signal indicating whether or not the vehicle is towing a trailer. The trailer module controls the trailer lighting. When a trailer is being towed, the trailer module automatically deactivates, for example the rear Park Distance Control (PDC) and the rear foglight on the vehicle. The automatic parking function is deactivated whenever a trainer is detected. (Automatic parking function: To improve the view of the curb, the mirror glass is folded downwards when reverse gear is engaged. This brings the area close to the bottom of the vehicle, i.e. the curbside, into view when parking.) The trailer module (AHM) is connected to the footwell module via the K-CAN.
3. DSC: Dynamic Stability Control When cruise control is in operation, the brake lights are actuated during automatic braking (legal requirement). To this end, a signal must be sent from the DSC to the accelerator pedal module via the PT-CAN.
4. FLA: Main-beam assistant In accordance with the traffic situation, the main-beam assistant sends a switch-on recommendation or a switch-off recommendation for the main-beam headlights to the light module or footwell module (FRM). On the basis of this recommendation and various other the input variables, the footwell module decides whether the main-beam headlights should be switched on or off.
5. FRM: Footwell module The footwell module is connected to the vehicle with three connectors. Two 51-pin connectors connect the main wiring harness. A further 26-pin connector is provided for the connection to the dashboard.
6. FZD: Roof control panel The roof control panel is responsible for the interior lighting components in the roof area. The basic variant of the roof control panel does not have its own control unit. The front interior lights and the rear interior lights are actuated by the footwell module (FRM). The High variant of the roof control panel has its own control unit: the FZD control unit. The footwell module is connected to the FZD control unit via the K-CAN.
7. JBE: Junction box electronics The luggage compartment lights and the glove compartment lighting are connected to the junction box electronics.
8. LDM: Longitudinal dynamics management In conjunction with the LDM, the option "Active Cruise Control" uses the "turn signal" signal from the footwell module to help when changing lanes. In other words, if a left turn signal is given before overtaking, the distance to the vehicle in front is reduced. The vehicle to be overtaken is "ignored" more easily. Conversely, when you move back into the right lane, vehicles being driven there will be monitored more quickly.
9. RLS/RLSS: Rain-light sensor/rain-light solar sensor E81, E82, E87, E90, E91, E92, E93: Rain-light sensor E70, E71: Rain-light solar sensor The rain-light sensor measures the ambient brightness outside the vehicle. Depending on the ambient lighting conditions, the footwell module will switch the driving lights on or off. To do this, the automatic driving lights control must be activated (light switch in switch position "A"). In twilight conditions, the rain-light sensor sends the message "Twilight". The footwell module switches the driving lights on. The automatic headlight-range adjustment for the dipped-beam headlights is actuated. In darkness, the rain-light sensor sends the message "Darkness". The adaptive headlights are then activated when the vehicle is cornering.
10. SZL: Steering Column Switch The switch signals from the turn-signal/main-beam switch are picked up and evaluated by the SZL. The evaluated switch signals are resistance-encoded and transmitted from the SZL by direct wires to the footwell module.

The following components are controlled

1. Exterior mirrors
2. Power window drive
3. Headlights
4. Rear lights
5. Front foglights
6. Additional brake light
7. Auxiliary turn signal light
8. Courtesy lighting, front
9. Courtesy lighting, rear
10. Licence-plate light
11. 2 stepper motor controllers for the adaptive headlight stepper motors
12. 2 belt feeder controllers (E92 only)