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Powertrain - Overview: Other BMW 3 series E46 facelift

Mechanical 11 illustrations ~1316 words

Engine

The previous M54/M56 engine is being replaced with a new engine variant referred to as the N52, which introduces a number of new technologies with regard to engine development.

The objectives in developing the N52 include

  1. Increased power output and torque
  2. Reduction of fuel consumption
  3. Reduction of overall engine weight
  4. Top position in engine class through efficient dynamics
  5. Utilization of innovations for customer benefit

By implementing some of the latest technology into the N52 engine, BMW met the objectives by improving the power to weight ratio, reduced emissions and decreased fuel consumption.

Scheme 61

Scheme 61

N52B30 Engine

The simplest way of achieving these objectives was to reduce the weight of the engine. By utilizing new engine development technology the N52 variant is 10 Kg (22 lbs) lighter than its predecessor, as a result of

  1. New composite magnesium-aluminum crankcase
  2. Lightweight exhaust manifold
  3. Magnesium bedplate
  4. Magnesium cylinder head cover.

Improvements have also been made with regard to the Valvetronic system (Valvetronic II) along with a new 3 stage DISA intake manifold, electric coolant pump and a new Engine Management (MSV70).

The introduction of these improvements provides the N52 with a 12% reduction in fuel consumption and a 10% increase in dynamics, compared to the previous engine (M54/M56). The increases in efficiency allow the N52 to comply with ULEV II standards.

For the U.S. Market the N52 engine will be available in the 330i and 325i, both engine variants will be designated N52B30.

Scheme 62

Scheme 62: Engine Power Output (N52B30 - 3.0 Liter)

Technical Data (N52B30)

DescriptionValue
Engine Type6 cylinder in-line
Displacement (cm 3 )2.996
Stroke/bore (mm)85.0/88.0
Cylinder spacing (mm)91
Crankshaft main bearing diameter6 @ 56mm / 1 @ 65mm
Crankshaft big-end (rod) bearing diameter50mm
Firing Order1-5-3-6-2-4
Power output (kW/hp)190/255
@ engine speed6,600
Torque300
@ engine speed2,500 to 4,000
Maximum rpm (governed cutoff)7,000
Power to weight ratio0.84
Power output per liter63.4
Compression ratio10.7
Valves per cylinder4
Intake valve diameter (mm)34.2
Exhaust valve diameter (mm)29
Minimum intake valve lift (mm)0.18
Maximum intake valve lift (mm)9.9
Exhaust valve lift9.7
Camshaft opening angle, intake (crankshaft degrees)255
Camshaft opening angle, exhaust (crankshaft degrees)263
Camshaft spread, intake (crankshaft degrees)120-50
Camshaft spread, exhaust (crankshaft degrees)115-60
Engine weight (kg.)161
Fuel requirement91 (98 RON)
Engine oilSAE 5W-30
Knock controlYes
Intake manifold3 Stage Resonance Intake Manifold (DISA)
Engine ManagementSiemens MSV70
Valvetrain SystemValvetronic II
Emissions CertificationULEV 2

TECHNICAL DATA SPECIFICATION

Components

The N52 engine consists of the following components/systems

  1. 6-cylinder, 4-valve in-line, friction optimized engine
  2. Two-piece crankcase in composite magnesium-aluminum structure
  3. Trapezoidal connecting rods (weight optimized)
  4. Aluminum silicon (Alusil) cylinder head
  5. Timing case integrated in crankcase and cylinder head
  6. Cylinder head gasket with silicon sealing lip
  7. VALVETRONIC II
  8. Weight-optimized double VANOS
  9. Volumetric flow-controlled oil pump
  10. Electrically controlled coolant pump
  11. Crankcase ventilation with integrated heater
  12. 3-stage DISA

Engine Management (MSV70)

There are several new innovations introduced with the new MSV70 engine management system. The most obvious innovation is the addition of Valvetronic II to the six-cylinder engine line. This is the first use of Valvetronic on the BMW six-cylinder.

The MSV70 engine management system is responsible for the following tasks

  1. Ignition control
  2. Injection control
  3. VALVETRONIC II control
  4. Control of "Weight Optimized" double VANOS
  5. Engine temperature control (characteristic map control of engine thermostat)
  6. Electric coolant pump control (Heat Management System)
  7. Knock control
  8. Lambda control
  9. Fuel tank ventilation control
  10. Load request to air conditioning control unit for A/C compressor
  11. Activation of 3-stage differentiated intake manifold (DISA)
  12. Electric fuel pump module control (EKP)
  13. Cruise control
  14. Alternator control
  15. Heated crankcase ventilation
  16. Electronic oil condition monitoring and oil level monitoring
  17. Energy management (IBS)
  18. Monitoring of input and output signals
  19. Calculation of substitute signals and failsafe functions
  20. Self-diagnosis

The engine management system on the N52 engine complies with OBD regulations and meets the ULEV II requirements for 2006.

Control Module

The new MSV70 control module is manufactured by Siemens/VDO. The "MSV" designation indicates a Siemens control module (Motor Control with Valvetronic).

The control module features an all aluminum housing with a new modular connector configuration. The control module has two main connections, one with 4 modular connections and the other with 3 for a total of 7 "sub" connectors. This arrangement provides a total of 146 possible pin connections.

Processor Power

The computing power has been increased to a clock frequency of 60 MHz to accommodate the extended functions.

Scheme 63

Scheme 63: Processor Power

Scheme 64

Scheme 64: MSV70 System Overview
IndexExplanationIndexExplanation
1DME (ECM)38Diagnosis connection
2Integral ambient temperature sensor39Valvetronic relay
3Integral ambient pressure sensor40Oxygen Sensor
4DME (ECM) main relay41Oxygen Sensor
5DM-TL42Oxygen Sensor
6IHKA43Oxygen Sensor
7Electric engine cooling fan44Valvetronic motor
8E-Box fan45Knock sensor (cyl 1-3)
9Characteristic map thermostat46Knock sensor (cyl 4-6)
10Crankcase ventilation heater47Eccentric shaft sensor
11Crankcase ventilation heater relay48Hot-film air mass meter (HFM)
12Secondary air pump49Exhaust camshaft sensor
13Secondary air pump relay50Intake camshaft sensor
14HFM for Secondary air51Crankshaft sensor
15Fuel tank vent valve (TEV)52DISA actuator
16VANOS solenoid valve (Intake cam)53DISA Actuator
17VANOS solenoid valve (Exhaust cam)54Electric Throttle Valve (EDK)
18Electro-magnet for airflap control (not for US)55Accelerator Pedal Module (FPM)
19-24Fuel injectors56SPORT button
25Fuel injector relay57Coolant temperature sensor (engine temp)
26-31Ignition coils58Coolant temperature sensor (radiator outlet)
32Electric coolant pump59DSC module
33Intelligent Battery Sensor (IBS)60Brake Light Switch (BLS)
34Alternator61Clutch switch
35Oil Condition Sensor (OZS)62Car Access System (CAS)
36Ground connection63Differential pressure sensor
37PT-CAN64Oil pressure switch

LEGEND FOR MSV70 SYSTEM OVERVIEW

Transmissions

On the E90 a six speed manual transmission (GS6-37BZ) will be standard and a six speed automatic transmission with STEPTRONIC (GA6HP19Z) will be optional.

Manual Transmission

The Manual Transmission (GS6-37BZ) available on the E90 is the same as that used previously on the E46 and currently on the E60 & E85. The transmission has a lifetime oil fill.

Scheme 65

Scheme 65: Manual Transmission

Automatic Transmission

For the first time the 3 series will see a six speed Automatic Transmission (GA6HP19Z) with STEPTRONIC.

Scheme 66

Scheme 66: Automatic Transmission

The transmission is similar to that used in the E60 with the M54 engine. In order to utilize this transmission on the E90 changes were made to

  1. Outer gearshift mechanism with electrical interlock
  2. New transmission control module
  3. Adapted hole circle diameter at the output flange

Scheme 67

Scheme 67: External Gearshift Mechanism

The external gearshift mechanism consists of the selector lever with the following components

  1. Cable assembly to gearbox
  2. Solenoid valve for shiftlock function
  3. Solenoid valve for interlock function
  4. Microswitch for detecting locked shift lever
  5. Emergency release of interlock function
  6. Switch unit for Steptronic function
  7. Selector lever position switch indicator

Shiftlock

The shiftlock function prevents the vehicle from inadvertently being placed in gear with the ignition on, unless the brake pedal is depressed. A solenoid is used to lock the shift lever in position P or N once the ignition is switched off and the lever has been placed into position P or N. The solenoid is activated by a switched ground signal from the Transmission Control Module

Interlock

The interlock function prevents removal of the remote control "key" when the selector lever is not in position P. The selector lever remains locked in position P if the remote control "key" is not inserted in its slot. For this purpose, the selector lever is locked in position P by two electric magnets once the ignition is switched off.

Interlock Without Comfort Access

The selector lever is locked in position P after ignition OFF and the radio remote control "key" can be removed.

The microswitch on the selector lever unit monitors the lock state of the selector lever and sends the signal to the CAS to release the radio remote control once the selector lever is in position P.

Interlock with Comfort Access

When the vehicle is stationary, the engine or terminal 15 can only be turned off when the selector lever is in position P.

Scheme 68

Scheme 68: Interlock with Comfort Access

Emergency Release

In case of an emergency (e.g. failure of the power supply system), the selector lever can be released by operating the emergency release. The emergency release is accessible by removing the selector lever cover. The selector lever is released by pressing on the pawl (1).

Transmission Control Module

The newly developed Transmission Control Module (GS 19.11) is used for the automatic transmission GA6HP19Z (in all models). Compared to its predecessor (GS 19.04) it offers the following advantages

  1. Flash memory expanded from 512 Kbit to 1 MB
  2. Designed to withstand higher temperatures
  3. Electromagnetic compatibility considerably improved
  4. Reserve for further functions

The Transmission Control Module is located on the mechatronics module in the gearbox with the same housing and pin assignments from the previous version.

Stationary Disconnection

The gearbox features a stationary disconnection (uncoupling) function for the torque converter. The torque converter is disconnected from the drivetrain instead of running the engine against the torque converter when the vehicle is stationary. By disconnecting the torque converter with the vehicle stationary, the engine is subject to minimum load and fuel consumption is reduced.

Disconnection (uncoupling) of the torque converter is achieved as a function of the following signals

  1. Brake operated
  2. Selector lever position D
  3. Gear oil temperature > 20°C and < 120°C
  4. No trailer signal applied

Scheme 69

Scheme 69: Automatic Transmission Selector Lever - Circuit Diagram

Drive Shaft

The E90 utilizes a two piece steel drive shaft with a deformation element (collapsing tube similar to E60).

Scheme 70

Scheme 70: Drive Shaft

Scheme 71

Scheme 71: Final Drive/Differential

The differential unit 188 L (L = low friction) is used for the first time on the 3 series.

The 188 L differential uses angular-contact ball bearings (1), compared to the linear contact of tapered roller bearings, the point contact of the angular-contact ball bearings produces less friction. By reducing friction the temperature of the gearbox is reduced which in turn increases efficiency.

The differential utilizes a lifetime fill oil.

Output Shafts

Solid shafts, torsionally-rigid hollow shafts or torsionally-flexible hollow shafts are used depending on the engine-gearbox combination.

The joint size also varies corresponding to the engine-gearbox combination.