BMW 3 ELECTICAL SYSTEM Reparaturanleitung

Initial Print Date: 03/05Table of ContentsSubject PageVehicle Electrical System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

10E90 Voltage Supply & Bus SystemsIBS Measuring /Evaluation FunctionThe measuring/evaluation function of the IBS electronics, continuously measure

11E90 Voltage Supply & Bus SystemsServicing the IBSThe IBS is very sensitive to mechanical stress and strain. It is serviced as a complete unitwit

12E90 Voltage Supply & Bus SystemsTerminal 15 Wake-up Signal FaultsThe IBS recognizes wake-up line faults. The IBS can detect a wake-up line erro

13E90 Voltage Supply & Bus SystemsVehicle Ground PointsXXXXXXXXXXXXXXXXX

14E90 Voltage Supply & Bus SystemsClassroom Exercise - Review Questions1. What components make up the rear power distribution?2. What information

15E90 Voltage Supply & Bus SystemsNOTESPAGE

On the 3 series (E90) the Junction Box (JB) plays acentral role in the distribution of power to the variouscomponents installed in the vehicle. Based

17E90 Voltage Supply & Bus SystemsWithin the distribution box itself fuses and relays are plugged directly into the PC boardas well as directly in

18E90 Voltage Supply & Bus SystemsThe upper left corner of the junction box provides an interface connection directly to thevehicle wiring harness

19E90 Voltage Supply & Bus SystemsJunction Box Electronic Control Module (JBE)Not only does the Junction Box serve as a power distribution center

Subject PageElectric Load Reduction - Engine Running . . . . . . . . . . . . . . . . . . . . .34Electric Load Cut-Off with Engine Off . . . . . . .

20E90 Voltage Supply & Bus SystemsThe Distribution Box interface/connection point (X4010) to the Electronic Control Moduleis located in the lower

21E90 Voltage Supply & Bus SystemsClassroom Exercise - Review QuestionsJunction Box1. What function does the Junction Box serve?2. What function d

The bus structure in the new BMW 3 Series (E90) builds on the technology being usedin the current models . In the E90 the Junction Box Electronic Con

23E90 Voltage Supply & Bus SystemsMain bus systems are responsible for the data exchange between the control modulesthroughout the vehicle system.

24E90 Voltage Supply & Bus SystemsWUPFSMOSTPT-CANBSDLIN-BusD-BusK-CANF-CANK-Bus (protocol)8xJBESBFARLSFRM CIDKombi CON CDCTOP-HIFIUSISSINESMFAFZD

Legend for Bus System Overview - E90 U.S.25E90 Voltage Supply & Bus SystemsIndex Explanation Index ExplanationACC IIActive Cruise Control 2K-BusBo

26E90 Voltage Supply & Bus SystemsK-BusThe K-Bus serves the purpose of linking the OC3 mat (Seat Occupancy Recognition) tothe MRS 5 Control Module

27E90 Voltage Supply & Bus SystemsMOST BusThe new 3 series (E90) uses a MOST-Bus structure, similar to that used onE60/61/63/64/65/ & E66, as

28E90 Voltage Supply & Bus SystemsLight DirectionEach control module on the MOST-Bus is able to send data, however it can only be sentin one direc

29E90 Voltage Supply & Bus SystemsFiber Optics ConnectorThe use of a fiber optics connector provides the advantage of being able to easily retrofi

Voltage Supply & Bus SystemsModel: E90Production: From Start of Production3E90 Voltage Supply & Bus SystemsAfter completion of this module you

30E90 Voltage Supply & Bus SystemsDiagnosis InformationData Flow InterruptionSeveral factors can cause an interruption in the data flow in the MOS

31E90 Voltage Supply & Bus SystemsNOTESPAGE

32E90 Voltage Supply & Bus SystemsClassroom Exercise - Review QuestionsBus Systems1. What module serves as the main gateway?2. What module(s) serv

33E90 Voltage Supply & Bus SystemsA power management function some what similar to that used in the E60 is also used inthe E90 to ensure balanced

34E90 Voltage Supply & Bus SystemsPower Consumption During OperationDuring vehicle operation, the mechanical energy of the engine is converted by

35E90 Voltage Supply & Bus SystemsElectric Load Cut-Off with Engine OffCertain electric loads may be active although the engine is off and the clo

36E90 Voltage Supply & Bus SystemsTerminal 30g Relay (Time-Dependent Deactivation)The terminal 30g relay is controlled bythe CAS, which switches o

37E90 Voltage Supply & Bus SystemsTerminal 30g_f Relay (Fault-Dependent Deactivation)The Junction box control module controlsthe 30g_f terminal, w

38E90 Voltage Supply & Bus SystemsTerminal 30g_f is switched ON with:• Vehicle unlocked• Terminal change from R “Off” to R “On” or terminal 15• Ch

39E90 Voltage Supply & Bus SystemsTerminal 30 (KL30)A number of control modules are con-nected to terminal 30 via the junction box.Workshop Exerci

4E90 Voltage Supply & Bus SystemsIntroductionThe voltage supply system on the E90 uses a Junction Box (JB) with a control moduleas a primary power

40E90 Voltage Supply & Bus SystemsTerminal 15 (KL15)The only module on the BUS effected byTerminal 15 relay is the PDC ControlModule.The terminal

41E90 Voltage Supply & Bus SystemsSystem Diagnosis InformationThe control modules for the DME/ECM and Junction Box (JB) provide various forms ofin

42E90 Voltage Supply & Bus SystemsClosed Circuit CurrentThe closed-circuit current on the E90 is:• Approx. 22 mA on fully equipped US vehicles.A

43E90 Voltage Supply & Bus SystemsTransport ModeThe following functions are switched off and on in the E90 when vehicle is placed intotransport mo

44E90 Voltage Supply & Bus SystemsTransport Mode Cont.Index Function ModuleTransportMode(O-On/X-Off)27Radio control master function for deactivati

45E90 Voltage Supply & Bus SystemsWorkshop Exercise - Power ManagementIdentify/Highlight specific control modules related to the following reques

46E90 Voltage Supply & Bus SystemsClassroom Exercise - Review Questions1. Under what conditions is the circuit for term.30g_f switched off?2. Desc

5E90 Voltage Supply & Bus SystemsBattery ConnectionsLocated on the right side of the luggage compartment is the battery, from here power issupplie

6E90 Voltage Supply & Bus SystemsRear Power DistributionAttached directly to the top of the battery is the rear power distribution box which con-t

7E90 Voltage Supply & Bus SystemsBattery Safety TerminalThe Battery Safety Terminal (BST) is used to reduce the risk of a short circuit to the B+t

8E90 Voltage Supply & Bus SystemsIntelligent Battery Sensor (IBS)The Intelligent Battery Sensor (IBS) as a mechanical/electronic device which is c

9E90 Voltage Supply & Bus SystemsThe IBS is able to withstand thermal loads up to 105°C, the chemical effects of the bat-tery acid.The components