Page 2 - X5 Updates
2 X5 Updates X5 Updates Model: X5, X5 4.6 iS Production: 9/02 Objectives: After completing this module you should be able to: • Recognize the components of EHC2 • Locate the EHC2 components • Understand the operation and diagnose EHC2 • Recognize the X5 4.6iS • Relate the additions and modification ...
Page 3 - Two Axle Air Suspension; Purpose of the System
3 X5 Updates Two Axle Air Suspension Purpose of the System The two axle air suspension system (EHC2) offers advantages over the single-axle air sus-pension with respect to ride comfort and off-road capability.Lowering the entire body makes it easier to enter, exit, load and unload the vehicle.The ve...
Page 4 - System components; Pneumatic System of EHC2
4 X5 Updates System components The X5 Two Axle Air Suspension System (EHC2) utilizes the air supply unit from EHCmounted in the luggage compartment, with the following components added or modified: • Air Supply Unit (with redesigned compressor and drier) • Pressure Accumulator • Valve Unit • Ride He...
Page 5 - Pneumatic Drain Valve; Air Supply Unit
5 X5 Updates Pneumatic Drain Valve The Pneumatic Drain Valve is activated pneumatically by pressure from the control valve.This causes the drain valve to open allowing the pressure supply line to vent to atmosphere.This design allows for large air volumes to be discharged quickly and eliminates the ...
Page 6 - Compressor; Extended compressor ON time (180 seconds); Pressure Accumulator; Compressor with Drier
6 X5 Updates Compressor Compressor operation is the same as in EHC with the following technical improvements:• Addition of a temperature sensor (Located on the compressor cylinder head)Temperature sensor switches off the compressor at temperatures above 110 0 C. • Extended compressor ON time (180 se...
Page 7 - Accumulator/Valve Unit
7 X5 Updates The pressure accumulator decreases the load on the compressor and significantly reducesthe time required for large changes in ride height.The EHC 2 control module monitors system pressure via a pressure sensor mounted onthe accumulator. Normal system pressure is 15.7 +/- 0.7 bar. Minimu...
Page 8 - Ride Height Sensor; Front Axle
8 X5 Updates Ride Height Sensor The control unit obtains information about the ride height of the vehicle via a ride height sen-sor attached to each of the four wheels. The ride height sensor is an angle Hall sensor which is activated by a ring magnet. The ringmagnet is polarized vertically from nor...
Page 9 - Air Suspension Strut
9 X5 Updates Air Suspension Strut Rear Minor modifications were made to the rear axle air springs. The air springs and the dampersare configured separately at the rear axle. Front The air suspension replaces the steel suspension at the front axle, i.e. the spring bellows isattached to the damper. Th...
Page 10 - Switch Assembly
10 X5 Updates Switch Assembly The dash mounted switch assembly supplies a momentary switched ground to the EHC2Control Unit requesting a ride height change in the up or down direction. Three LED’s pro-vide current ride level selected and target ride level if a request for change has been made.The LE...
Page 11 - Principle of Operation
11 X5 Updates Principle of Operation Ride Height Control Operations In addition to the automatic ride-height control system for payload compensation, the dri-ver can set three different vehicle ride heights. • Off-road (+25 mm), high ground clearance to a max. speed of 50 km/h • Standard (0 mm), nor...
Page 13 - For safety-critical faults (vehicle is too high or at inclination); Control Modes
13 X5 Updates In addition to the LED indicator, the following text messages canbe displayed in the instrument cluster: • T TR RA AIIL LE ER R M MO OD DE E A coupled trailer is identified via the trailer connector. To avoid damaging the trailer andthe vehicle, changes of vehicle level are generally a...
Page 14 - Sleep
14 X5 Updates All control operations in advance / overrun mode are executed as long as pressure is avail-able in the accumulator. When the accumulator is empty and the engine is turned off, con-trol operations are directly driven by the compressor. User-activated changes of ride leveland filling of ...
Page 15 - Workshop Hints; The original level values are undershot at all four wheels,; Vehicle jack
15 X5 Updates Workshop Hints If a threshold level is exceeded on all 4 wheels when the vehicle is stationary, the controlunit assumes that the vehicle has been raised on a workshop platform.There are three possible reset conditions for workshop platform recognition: • The original level values are u...
Page 16 - Important Workshop Hint
16 X5 Updates If the fabric of the bellows is visible, then the bellows must be replaced. Upon completion of repair work, the air suspension system of the vehicle raised on theworkshop platform must be refilled with air via the diagnostics. The activation proceduresmust also be repeated 6 times. Thi...
Page 17 - Engine
17 X5 Updates X5 4.6 iS The X5 4.6iS is an additional model added to the X5 family of SAV’s. The 4.6 receivesmodel code FB93/0266 and is available start of production 10/01. Features added to the 4.6 versus the 4.4: • Increased Engine Displacement/Horsepower • Increased Transmission Capacity • Upgra...
Page 18 - Transmission
18 X5 Updates Transmission The X5 4.6iS is available only with a ZF A5S 440Z 5-speed automatic transmission whichfeatures modified internal components. Many internal components, including the torqueconvertor have been modified to handle the increased torque and horsepower. The transmission is specif...
Page 19 - Additional Standard Features
19 X5 Updates Additional Standard Features The following equipment is added to the 4.4 model equipment for the X5 4.6iS: Glass Moonroof Roller Sun Blinds For Rear Doors Self Dimming Mirrors Rear Seat Back Adjustment Rear Seat Heating PDC Rain Sensor Premium Sound System CD Changer Privacy Glass Colo...
Page 20 - Review Questions; List the advantages of the EHC2 over EHC as used in the X5.
20 X5 Updates Review Questions 1. List the advantages of the EHC2 over EHC as used in the X5. 2. What component is responsible for limiting the maximum pressure in the EHC2? And what is the maximum pressure/minimum pressure? 3. Why is a pressure accumulator used? 4. The control unit for EHC2 is loca...