Steering and Wheel Alignment - Service Techniques BMW X5 E70

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INTRODUCTION

Active Steering is the most recent BMW development in the innovative steering systems sector.

Active Steering varies the steering gear ratio from direct to indirect and vice versa as a function of the vehicle's speed.

The benefits of Active Front Steering are

1. direct steering with no more than minimal movements of the steering wheel at the low end of the speed range
2. More indirect steering at higher speeds in conjunction with yaw-rate control

Active Steering, including Servotronic, is available as an option (option 217).

Active Steering gives the vehicle an even sportier character.

New for the E70 is the 3rd generation Active Steering

1. Yawing moment compensation has been fully integrated as a function in the Active Steering control unit
2. Cumulative steering angle sensor discontinued
3. Digital motor-position sensor
4. Commissioning exclusively via service function in BMW diagnosis system

On the X5, Active Steering is available for the first time on an all-wheel drive vehicle.

In 03/2007 the actions described for the E70 will also be implemented on the BMW 5-Series. Other model series will follow later.

Note. On vehicles without active steering. Option 216 "Servotronic" is not available without Active Steering.

Note. On BMW 3-Series not with trailer coupling. Active Steering is not available in conjunction with option 3AC "Trailer coupling with folding ball head".

New for the BMW 3-Series was

1. Yaw moment compensation as additional function
2. Output stages for the Servotronic valve and the ECO valve are integrated into the Active Steering control unit
3. Only 1 DSC sensor (redundant)

New for the BMW 5 and 6-Series from 09/2005 was

1. Active Steering control unit taken from BMW 3-Series
2. This allows the Servotronic valve and the ECO valve to be directly actuated by the Active Steering control unit
3. Only 1 DSC sensor as on BMW 3-Series

Note. On BMW 5 and 6-Series vehicles without Active Steering from 09/2005. With option 216 "Servotronic", the body gateway module (KGM) actuates the Servotronic valve.

A conventional steering system inevitably constitutes a compromise

on the one hand, the steering cannot be too direct as otherwise it would be overly sensitive when the vehicle is travelling at high speed. On the other hand it is practical to have much more direct steering for maneuvering at low speeds and for parking. The new Active Front Steering system is the ideal trade-off. The directness of the steering of a vehicle fitted with AFS varies with speed.

This results in three major benefits

1. enhanced agility
2. enhanced comfort
3. enhanced safety Enhanced agility Up to about midway through the speed range (about 100 km/h), the directness of the steering means that the driver perceives the vehicle as more agile and easier to handle. A driver who has to avoid an unexpected obstacle, say, has much better control, plus significantly enhanced steering precision and less work at the steering wheel. There is no loss in feedback from the road surface right through the steering wheel. Enhanced comfort Current BMW models need more than three full turns of the steering wheel in order for the wheels to describe the arc from full lock in one direction to full lock in the other. When the vehicle is travelling at low speed, Active Steering reduces this to less than two full turns of the steering wheel from lock to lock. The advantage: The driver's task is easier when turning corners in city traffic or when maneuvering into parking slots where space is at a premium. On twisty roads such as mountain passes, moreover, the reduced steering angle means that the driver's hands remain in the ideal position on the wheel. There is no longer any need for the driver to feed the wheel through his or her hands, or to cross hands in a tight bend. The multifunction buttons on the steering wheel and the paddles for the sequential manual transmission (SMG) are always perfectly positioned relative to the driver's hands, regardless of the driving situation. Enhanced safety A completely different set of conditions applies when the vehicle is travelling at high speed: With the assistance of indirect steering there is increased stability when travelling straight ahead at high speeds (such as on motorways) compared with conventional steering. At the same time, the yaw-rate control is in the position to stabilize the vehicle by correcting the steering angle when the vehicle is oversteering. This supports the Dynamic Stability Control (DSC) function. Like conventional systems, BMW's Active Front Steering features a steering column with a permanent connection from the steering wheel to the front wheels. This mechanical link ensures the operability of the steering system at all times, even in the event of disruption to or the complete failure of the system. The mechanical steering linkage, what is more, is essential in sustaining the authentic "feeling of steering" as perceived by the driver. True steer by-wire systems are intrinsically unable to simulate the realism of this feedback from the road to the driver.

BRIEF DESCRIPTION OF COMPONENTS

The sensors incorporated into the Active Front Steering system are

1. Motor-position sensor The motor-position sensor registers the rotor position of the electric servomotor. The rotor position is communicated to the control unit for Active Steering (AL control unit). The 3rd generation Active Steering includes a digital motor-position sensor.
2. Cumulative steering angle sensor and steering angle sensor The cumulative steering angle sensor captures the steering angle that the Active Steering produces at the steering box. As far as its function is concerned, the cumulative steering angle sensor corresponds to the steering angle sensor in a conventional steering system. The steering angle sensor in the steering column switch cluster registers the angle to which the driver turns the steering wheel. Both signals are needed by the control unit for Active Steering (AL control unit). > From E70 (other model series to follow) The cumulative steering angle sensor on the X5 is discontinued. Active Steering computes a "virtual" cumulative steering angle. The virtual cumulative steering angle is derived from the following signals: Steering angle sensor signal Motor-position sensor signal The steering angle sensor on the BMW 1 and 3-Series is an optical sensor. From 09/2005, the BMW 5 and 6-Series also have an optical steering angle sensor.
3. DSC sensor > E60, E61, E63, E64 up to 09/2005: 2 DSC sensors transmit redundant signals capturing the rate of yaw (rotation about the vertical axis) and lateral acceleration to the AL control unit via the chassis CAN (F-CAN). > E70, E81, E87, E90, E91, E93, E93 Only 1 DSC sensor is needed for the Active Steering. This DSC sensor transmits redundant signals capturing the rate of yaw and the lateral acceleration. > E60, E61, E63, E64 from 09/2005 Only 1 DSC sensor is needed for the Active Steering. This DSC sensor transmits redundant signals capturing the rate of yaw and the lateral acceleration.

The control units networked for the purposes of AFS are as follows

1. AL: Active Steering control unit The AL control unit computes the nominal values for the electric servomotor of the planetary gearbox with override function.
2. SZL: Steering Column Switch The Steering Column Switch provides the steering angle.
3. SGM: Safety and gateway module > E60, E61, E63, E64 up to 09/2005 The safety and gateway module (SGM) drives the ECO valve in the power-steering pump and the Servotronic valve. Moreover, the SGM forms the interface between the PT-CAN and the K-CAN (signals for instrument cluster).
4. KGM: Body gateway module > E60, E61, E63, E64 from 09/2005 The body gateway module (KGM) forms the interface between the PT-CAN and the K-CAN (signals for instrument cluster). With option 216 "Servotronic", the KGM actuates the Servotronic valve.
5. JBE: Junction box electronics > E70, E81, E87, E90, E91, E92, E93 The junction box electronics (JBE) forms the interface between the PT-CAN and the K-CAN (signals for instrument cluster). Moreover, the AL control unit receives its power supply from the distributor in the junction box.
6. DSC: Dynamic Stability Control The DSC control unit and the AL control unit are interconnected by the F-CAN (chassis CAN). The signals supplied by the DSC control unit include the road speed signal.
7. DME or DDE: digital engine electronics or digital diesel electronics The engine control sends the signal indicating that the engine is running to the AL control unit via the PT-CAN bus. The AL control unit notifies the engine control of the approximate drive torque of the power-steering pump.
8. CAS: Car access system The vehicle is authenticated by the AL control unit and the CAS control unit via the K-CAN / PT-CAN (vehicle identification numbers compared). Moreover, the CAS control unit transmits the wake-up signal for the PT-CAN.

The following actuators are actuated by the Active Steering

1. Planetary gearbox with override function and electric servomotor The planetary gearbox with override function uses the electric servomotor to generate the resulting cumulative steering angle at the front wheels.
2. Hydraulic steering with Servotronic valve The conventional hydraulic steering provides the power-steering assistance. "Servotronic" (= speed-dependent power-assisted steering) is part of the Active Steering option.
3. ECO valve in the power-steering pump A vehicle fitted with the "Active Steering" option has a controlled-output power-steering pump.
4. Warning light and Check Control The dedicated-function warning light in the instrument cluster lights up to indicate a fault in the Active Steering. At the same time a Check-Control message is shown in the LCD display. The text for the Check-Control message can be called up in the Central Information Display (CID).

SYSTEM FUNCTIONS

The Active Front Steering system comprises the following functions

1. Steering assistance (= Servotronic)
2. Variable steering-gear ratio (= Active Steering)
3. Yaw-rate control (= damping of dynamic yaw)

A new function will be added in further development leading to the start of series production of the BMW 3-Series

1. Yaw-moment compensation when braking on a road surface with non-uniform traction

In further development from the E70 , this function is entirely integrated in the Active Steering control unit (3rd generation). Further model series to follow.

Steering assistance

The steering assistance takes the form of conventional hydraulic steering (rack-and-pinion construction).

The speed-dependent steering assistance (= Servotronic) has been available in the E61 series since 03/2004. E63 and E64 have Servotronic as standard from start of series production. Servotronic has been standard on the E60 since 03/2005.

Active Steering and Servotronic are co-ordinated. Servotronic is controlled by the AL control unit.

The AL control unit actuates the Servotronic valve and the ECO valve in the power-steering pump via the Safety and gateway module (SGM). The ECO valve in the power-steering pump regulates the volume flow in the power-steering pump.

This arrangement means that only the volume flow needed for steering assistance at any given time is actually provided. In this way, the ECO valve affects the power consumption of the power-steering pump. Fuel consumption and carbon dioxide emissions (CO 2) from the vehicle's engine are reduced accordingly.

In vehicles without Active Steering, Servotronic is controlled directly by the safety and gateway module (except BMW 1 and 3-Series).

Clearly, therefore, the steering assistance and AFS are complementary, despite the fact that in terms of function, the two systems are fully independent of each other.

Variable steering-gear ratio

The variable steering-gear ratio function adapts the steering-gear ratio to the vehicle's road speed.

Steering is direct when the vehicle is moving at low speed. The planetary gearbox with override function contributes significantly to handling when the vehicle is moving at low speeds and when it is being maneuvered into tight parking spaces.

It is not longer necessary for the driver to feed the steering wheel through his or her hands in order to maneuver. When the vehicle is at a standstill, less than 2 complete turns of the steering wheel is all that is needed to move the wheels from lock to lock.

At high speeds the steering-gear ratio increases. The steering becomes less direct, further improving the intrinsically high standard of steering systems featured to date in BMW vehicles.

The safety function

The electric servomotor of the planetary gearbox is limited by an electric servomotor lock that blocks the worm gear of the planetary gearbox.

The electric servomotor lock is spring-loaded, with the force of the spring countered by the power supply. Any interruption of the power supply consequently locks the worm gear.

When the planetary gearbox is locked in this way, it ensures that the steering column enables the driver to steer the vehicle. Under these circumstances, the steering reacts like a conventional, direct, steering gear system.

The purely mechanical steering linkage between the steering wheel and the front wheels is sustained even if the Active Steering fails.

Yaw-rate control

If the vehicle tends to oversteer, for instance, when cornering, the yaw-rate control can correct the steering angle on the front wheels. This stabilizes the vehicle (with the emphasis on convenience and comfort). In this road situation, therefore, the Active Steering supports Dynamic Stability Control (DSC).

DSC does not intervene unless the stabilizing effect of the steering does not suffice to counteract the tendency to yaw.

Yaw-moment compensation when braking on a road surface with non-uniform traction

1. > BMW 1 and 3-Series

Active Steering now has an additional function for driving stabilization.

With conventional systems, the driver has to actively steer the vehicle in a straight line if the brakes are applied on a road surface with non-uniform traction levels.

In such situations, the Active Steering performs this active steering intervention, so stabilizing the vehicle.

Compared to pure ABS control, Active Steering with yaw moment compensation shortens the braking distance.

The driving stabilization function of the Active Steering can be deactivated together with DSC with the DTC button (when DSC is completely deactivated). Together with the hydraulic power steering, the variable steering-gear ratio is always active.

1. > From X5 (3rd generation)

This function is completely integrated in the Active Steering control unit. Other model series will follow later.

OPERATION

Unlike DSC, which can be switched off by means of the DTC button, Active Steering cannot be deactivated. Yaw-rate control and yaw-moment compensation are also deactivated when DSC is switched off. The variable steering gear transmission ratio always remains active.

With the 3rd generation Active Steering, the yaw-rate control remains active when DSC is deactivated.

When DTC is activated, the DSC response thresholds have been widened. Active Steering increasingly assumes the function of driving stabilization if the vehicle is oversteered.

PRECONDITIONS FOR ACTIVATION

Preconditions for activation for Active front Steering are

1. Terminal 15 ON
2. Engine running

Steering-wheel position and the position of the steered wheels are synchronized as soon as the engine is running. This ensures that the positions of the steering wheel and the road wheels match if, for example, the steering wheel was moved while the vehicle was at a standstill with the ignition switched OFF.

Note. The synchronization procedure can cause the steering wheel or the vehicle's front wheels to move. Movements of the steering wheel or the vehicle's front wheels might be perceptible while synchronization is in progress. Synchronization also occurs while the vehicle is on the move, but the process is extremely slow and virtually imperceptible.

Scheme 95

1.1 Objectives

Wheel alignment has become an increasingly complex subject. The aim of this BMW Service Technology bulletin, therefore, is to achieve several objectives

1. Creation of guidelines for working with the BMW Kinematic Diagnosis System (KDS).
2. Familiarization with wheel alignment technology for current vehicles and clarifying any questions which arise in this connection.
3. Transparency and clarification of different terms.
4. Clarification of the causes of errors in the past, such that they can be avoided after reading this document.
5. Creation of conditions for dealing safely with the BMW KDS.

1.2 Further development of the BMW Kinematic Diagnosis System

1. The BMW Kinematic Diagnosis System is an integrated part of automotive system concepts. It ensures that work is carried out in a particularly rational manner which is appropriate for BMW requirements, such that you can also be certain of being prepared for future technological developments. As far as precision and performance in wheel alignment and tuning is concerned, BMW, together with leading manufacturers, has made the best of what is technically feasible: the BMW Kinematic Diagnosis System.
2. The BMW Kinematic Diagnosis System manufactured by Beissbarth is more than just the further development of conventional wheel alignment equipment. It sets new standards in precision, performance, speed and handling. It is a guarantor for the perfection which BMW service customers rely on.
3. Ride comfort, road safety and tire wear depend to a large extent on the perfect interplay of the vehicle's kinematic functions. BMW is constantly launching new generations of chassis which are even better than their predecessors. This is why there are fewer kinematics system adjusting points and narrower tolerances when measuring and tuning the chassis.
4. With the use of the multi-link rear suspension and the E36, the electronic wheel alignment devices are no longer suitable for BMW wheel alignment purposes. This applies to both the measuring procedure and measuring precision. The generation of equipment which was approved with the E36 series still fulfils all the requirements placed on a modern wheel alignment device, including the use of the latest computer technology.
5. Only BMW Kinematic Diagnosis Systems manufactured by Beissarth and Bosch may be used for wheel alignment.

Scheme 96

TECHNICAL DATA REFERENCE

1.4 Scope of delivery

1. 1 PC display device with graphic screen, graphical tablet, small or large equipment cabinet including automatic charging station, DIN A4 dot matrix printer
2. 4 Measuring sensors with CCD camera technology and infrared data transmission with built-in power supply
3. 1 Cable set (comprising 4 cables)
4. 1 Brake clamping device
5. 1 Steering lock device
6. 2 Electronic precision rotating plates with integrated sensor without access ramps
7. 2 Sliding plates without access ramps
8. 4 BMW quick-clamping units, comprising a P8-68 locating bell and P267 01 quick-acting clamp including coated holding claws
9. 1 Operating instructions for BMW KDS (8 languages)
10. 1 BMW software and the BMW vehicle setpoint data with setting screens as well as text for the measurement preparations

1.5 Accessories required

1. 2 Locating rods for positioning the vehicle
2. 1 Set of sand bags for the prescribed loading

1.6 Accessories recommended

1. 4 Quick-clamping units
2. 2 Sets of access ramps
3. 1 Remote control / display
4. 1 Trolley (for ballast bags, rotating and sliding plates and 4 quick-acting clamps)

2.1 Front axle

1. Toe-in (single and total toe-in in relation to the geometrical drive axis)
2. Camber (with steering wheel pointing straight ahead)
3. Wheel displacement (in relation to the left-hand front wheel)
4. Castor, kingpin inclination and toe-differential angle

2.2 Rear axle

1. Toe-in (single and total toe-in in relation to the longitudinal center plane of the vehicle --> previously called symmetrical axis)
2. Geometrical drive axis
3. Camber

2.3 Other measuring options

1. Rear wheel displacement
2. Wheelbase difference
3. Lateral displacement on right
4. Lateral displacement on left
5. Track difference
6. Axial displacement

Scheme 97

The KDS 1 is available in two different designs at no extra charge

Scheme 98

Scheme 99

1. Mobile workstation
2. Mobile compact cabinet

The larger workstation offers a small storage area for accessories, while the compact cabinet is mobile and ideal for restricted working areas. Both variants can be supplied as a cableless measuring system (infrared). From the point of view of measuring technology, there is only a difference in the handling and equipping of the system. For both designs, the four measuring sensors are stored in integrated inserts with rechargeable battery charging points. When automatically charged over night, the measuring sensor batteries provide enough power for 10 hours of continuous use.

Scheme 100

1. The KDS 1 system comprises tested and reliable industrial components. The computer is an IBM-compatible, 32-bit Intel processor with CD ROM drive to the industry standard.

Scheme 101

1. All functions are shown in graphical form on a "pictogram" panel. The panel is protected by a plexiglass cover. It can easily be replaced if more extensive design modifications are necessary. The operator interface has no membrane and is thus protected against damage. The main functions are activated by clicking the icon with the digital pen.

Scheme 102

1. The PC with graphic monitor and removable operating panel, supports for the measuring sensors, the remote control and the A4 printer are integrated into the workstation. The charging station is located in the cabinet and can also be connected to the measuring sensors and the remote control using the plug-in cables (operating while simultaneously charging the batteries).

3.5 Remote display

A cableless remote display can be supplied on request. The remote control keys are only active during measuring and adjustment (not for customer data input, or if selecting a vehicle or editing the setpoint data etc.). The following displays are supported by the remote control

Scheme 103

1. Measured value with setpoint / actual comparison and tolerance bar
2. Steering graphics for steering routines
3. Live overview of the track / camber values with a setpoint / actual comparison
4. Rim run-out compensation

3.6 Measuring sensors with CCD camera

The measuring sensors are each equipped for automatic measurement with two CCD cameras and their own processor for the cableless infrared transmission of data with integrated batteries.

Benefits

Scheme 104

1. No temperature deviation
2. Very high measuring resolution (the track could theoretically be measured in angular seconds)
3. Single track range of more than ± 9 degrees for the constant display of toe-in when changing the tie-rod ends
4. Exact system accuracy, i.e. when carrying out measurements at the vehicle following rim run-out compensation, the toe-in and camber measurements are accurate to 2 angular minutes

Scheme 105

1. BMW quick-acting clamp for holding the measuring sensors precisely in position and measuring without rim run-out compensation.
2. NOTE: Any existing quick-acting clamps, e.g. from older F1600s or ML-3000s, must not be used on the BMW KDS.

Scheme 106

1. Electronic precision rotating plates for the front wheels with integrated sensor (360 degree measuring range)
2. Stable sliding plates for the rear wheels with a swivelling / rotating top plate
3. Accessories: Cover hood for aluminum rotating plates

Scheme 107

1. A new BMW light alloy wheel (styling no. 18) has been available as optional equipment from April 1993. When measurements are being made on vehicles with these wheels, new sensor pins are required for the quick acting clamps of the recommended wheel alignment equipment.
2. The new sensor pins are included in the scope of supply for new deliveries of KDS 1 (order number: BS 90 19 11).

Scheme 108

1. In the case of vehicles with very low spoilers, the sensor beam may be broken by the spoiler between the measuring sensors. This primarily occurs in front of the front axle.
2. The spoiler adapter is used here as a connecting element between the measuring equipment clamp and the measuring sensor. Thanks to the adapter, the sensors are placed 50 mm lower, thus allowing the sensor beam to move freely below the spoiler.

Scheme 109

1. Quick-clamping units for wheel alignment on non-BMW vehicles with rim run-out compensation.
2. Rims without sensors boreholes (rims for BMW vehicles from other manufacturers)

Scheme 110

1. The most varied clamping options for the measuring equipment are possible thanks to the versatile retainers and the rubber-coated thrust pieces, even on exotic light-alloy rims.

4.1 Environment

WORKSTATION REFERENCE

The support surfaces for the rotating and sliding plates may only display the following maximum height difference

Scheme 111

1. from left to right ± 0.5 mm
2. from front to back ± 1.0 mm
3. diagonally ± 1.0 mm.

Note. A difference in the height of the rotary plates of ± 2 mm from left to right results in a measuring error of 4.8 ° in the camber. As a comparison: The camber tolerance on the E36 is ± 10'. The tire tread difference or varying tire pressure cause measuring errors of the same magnitude.

4.2 Preconditions for alignment

When carrying out the wheel alignment, the front and rear wheels must be centered on the rotating and sliding plates in order that all wheel suspensions remain free of tension during the steering routine and adjustment work. As a result, the rotating and sliding plates for the relevant wheel bases and track widths of the vehicle to be aligned must be moved.

4.3 Measuring tolerance

All measuring tolerances are system tolerances. This means that the sum of all individual tolerances gives the value shown in the example. Example of camber: Quick-acting clamp + measuring sensor + computer = 1' at a measuring range of ± 3° (all BMW vehicles are within this measuring range).

4.4 Levelling the measuring station

The manufacturers of the BMW KDS (Beissbarth / Bosch) are able to measure the measuring area to the required accuracy using levelling devices. Any "normal" water level is not suitable for this. Lifting platforms must be levelled under load so that the uneven deflection in the travel rails is taken into account.

Scheme 112

1. The toe-differential angle (a) is the angular position of the internal wheel on the curve in relation to the external wheel on the curve when driving round bends. The steering is designed such that the angular position of the wheels in relation to each other changes as the steering angle increases.
2. In ideal cases, the wheel axes meet at point D in any steering position (except for straight ahead).

Scheme 113

1. The camber is the angle of inclination of the wheel in relation to the vertical.

Scheme 114

1. The toe-in is the reduction in the distance between the front of the wheels and the rear. The toe-in prevents the wheels from moving apart while driving (wobbling and grinding).

Scheme 115

1. The castor is the kingpin angle seen from the side in the opposite direction of travel. The line through the center of the spring strut mount and control arm ball joint corresponds to the kingpin.

Scheme 116

1. (1) The geometrical drive axis is the line bisecting the angle of the overall rear wheel toe. The measurements of the front wheels relate to this axis.
2. (2) The symmetrical axis represents the center line through the front and rear axes.

Scheme 117

1. The wheel displacement angle is the angular deviation of the connecting line of the wheel contact points in relation to a line running at 90° to the geometrical drive axis. The wheel displacement angle is positive if the right hand wheel is displaced to the front, and is negative if it is displaced to the rear.

Scheme 118

1. The kingpin offset is the distance from the center of the wheel contact point to the contact point of the kingpin extrapolation.

6. WHEEL SUSPENSION

Those parts which connect the wheel to the mostly load-bearing floor elements of the bodywork and guide it in the required direction belong to the wheel suspension. They are connected by axles or other comparable structures and guided by the arms. The wheel suspension plays a decisive role in the handling characteristics of a vehicle. Two main groups have to be distinguished: 1. Rigid axle suspension and 2. Independent wheel suspension.

6.1 Rigid axle suspension

RIGID AXLE SUSPENSION

6.2 Independent wheel suspension

INDEPENDENT WHEEL SUSPENSION

7.1 Measuring options

An overview of all measuring options and values (VA = front axle, HA = rear axle) is shown below.

WHEEL ALIGNMENT PROCEDURE

Note. The measuring accuracy details only apply when using the precision rotating and sliding plates as well as the BMW quick-acting clamps.

7.2 Preparatory work

Before commencing the measurement, preparatory work must be carried out at the measuring area and on the vehicle. Preparatory work includes

1. Easy-running rotating and sliding plates
2. Aligning the rotating and sliding plates in relation to the track width and wheelbase
3. Centering the vehicle on the plates
4. Applying the parking brake
5. Removing the lock pins on the plates to prevent tension in the chassis under loading
6. Checking the rim and tire size, tread depth, tire pressure, steering wheel play, wheel bearings and condition of suspension and shock absorbers
7. Fastening the measuring equipment to the wheels
8. Loading the vehicle according to BMW KDS specifications
9. Rock the vehicle firmly with the brakes released to ensure a stable center position
10. Lock the service brake using the brake clamping device

7.3 Initial / final measurement

This measurement can be carried out as a program-guided measurement in the same way as any subsequent adjusting work and the final measurement. The sequence of the chassis measuring points to be called up is specified and controlled by the system software. The individual steps comprise

1. Driving straight ahead to correctly record the wheel toe and camber values for the rear axle
2. Steering routine for recording the castor, kingpin inclination and toe-differential angle
3. Recording the wheel toe and camber of the front axle (adjust the steering center point in advance)
4. Steering routine for measuring the maximum steering angle on the left/right
5. Checking the overview of measured values with the setpoint and actual comparison of all measured values

Scheme 119

The report printout from the integrated DIN A4 printer is subdivided into three sections

1. Header lines with customer and vehicle identification data --> the customer data entered before beginning the measurement as well as vehicle data are printed out here.
2. Centre section with vehicle data --> this includes the make, type, model and vehicle model year defined when the setpoint data record was selected. The values previously measured for height level, tire pressure and tread depth are also printed in this section.
3. The end section with all vehicle alignment values comprises the 3 columns initial measurement, setpoint values and output measurement. The measured values are recorded separately in these three columns.

8.1 Free wheel alignment

With free wheel alignment the selection and sequence of the measuring points is freely selectable. The following points must be observed for attaining the correct measurement results

1. Carry out all work in the same way as with the program-guided measurement.
2. Before measuring the wheel toe and camber values for the rear axle, the steering must be in the "straight ahead" position to ensure that it is perfectly aligned in relation to the longitudinal center plane of the vehicle.
3. Before measuring the single wheel toe values on the front axle, the center of steering must be established to ensure the correct position of the steering wheel.

8.2 System settings

The following settings must only be entered or set once: language, display format, date/time, advertising text, remote control with display, rotating plate selection and printer settings. They remain stored.

9. BMW KINEMATIC DIAGNOSIS SYSTEM COMPARISON (BOSCH - BEISSBARTH)

KINEMATIC DIAGNOSIS SYSTEM

10.1 Remote control with display

The following steps show how the remote control with display is activated

1. Call up the "Service" menu in special functions ( "S" key)
2. Call up the "Remote control" sub-menu in the "Service" menu.
3. Select the "Remote control with display" item in the "Remote control" sub-menu - this configuration is retained.

10.2 Brief operating instructions

1. Activate the remote control with the "ON" button (it may also be switched on during alignment). The title page will appear on the LCD.
2. Select "Straight ahead" of the "Initial measurement" , "Adjustment work" or "Final measurement" at the measuring equipment cabinet. The steering graphics for "Straight ahead" will appear on the LCD.
3. Use the "Forward arrow" to change to the next measurement image. Display blocks will appear on the LCD with the designation of the measured value and tolerance bar with the measured value. If the measured value is within the tolerance range, it is shown in dark figures against a light background. If the measured value is outside the tolerance range, it will be shown in inverse video (light figures against a dark background).
4. By pressing the "F" key shortly, you can move alternately between the designation of the measured value and the setpoint value with the tolerance inside the display blocks.
5. You can scroll through the measured values using the "Forward arrow" , "Backward arrow" and "Cancel" (red dot) keys. The function of these keys is identical to that of the keys on the graphics panel.
6. Even with "Free alignment" , it is possible to scroll through the measured values in the same way as with "Program-guided alignment".
7. During measurement, the report print-out can be initiated using the "Printer" key. The remote control keys are only active during measurement and adjustment (not during customer data input, vehicle selection etc.).

10.3 Display support

1. Measured values with a setpoint/actual comparison and tolerance bar (setpoint figures can be displayed with the "F" key)
2. Steering graphics for steering routines
3. Overview of measured values with current setpoint/actual comparison
4. Rim run-out compensation
5. With all other functions (e.g. customer input), the title illustration appears on the LCD display

Note. If the data transmission from the remote control to the computer is interrupted, the remote control icon in the bottom right-hand corner of the screen changes color from green to red and the illustration on the LCD display is shown inversely - black turns to white, white to black. This change does not take place in the title illustration. Once the line-of-sight connection has been re-established, the remote control continues to operate from the point of interruption in the program. A continuous visual connection during alignment is therefore not necessary.

1. The "Hour glass" icon in the LCD display means: "Please wait".
2. The "Battery" icon in the top right-hand corner of the LCD display means that the battery reserve has been reached.
3. To switch off the remote control: press the "F" key for 5 seconds, then return it to its charging unit or connect it to a charge cable. The title illustration will again appear as a charging check.
4. If, during the measurement, the remote control has been placed back in the charging unit, it must be switched on again using the "ON" button.

11. UPDATING THE SOFTWARE / SETPOINT DATA

Floppy disks will no longer be sent to BMW partners who have acquired a "BMW KDS (Beissbarth / Bosch)". For cost-related reasons, you can create these disks yourself on the "DIS-tester" or on the "TIS/EPC server". The data for this is regularly updated on the TIS CD.

11.1 Requirements

1. BMW KDS (Beissbarth / Bosch)
2. TIS CD program status (Beissbarth): from CD 12/95
3. EPC program status: from 12/95
4. TIS CD program status (Bosch): from CD 08/97
5. DIS program status: from V6.0
6. 3.5" diskettes, 1.44 MB (Beissbarth 5 diskettes / Bosch 1 diskette)

11.2 Procedure (Beissbarth)

1. Go to the "Administration" screen
2. Select the KDS button
3. Select Beissbarth
4. Insert "Diskette 1" on request and confirm with "OK" (program diskette 1 of 2 is created, label it)
5. Insert "Diskette 2" on request and confirm with "OK" (program diskette 2 of 2 is created, label it)
6. Insert "Diskette 3" on request and confirm with "OK" (setpoint data diskette 1 of 3 is created, label it)
7. Insert "Diskette 4" on request and confirm with "OK" (setpoint data diskette 2 of 3 is created, label it)
8. Insert "Diskette 5" on request and confirm with "OK" (setpoint data diskette 3 of 3 is created, label it)
9. Perform update and/or setpoint data on the KDS in the usual manner with the diskettes which have just been created.

11.3 Procedure (Bosch)

1. Go to the "Administration" screen
2. Select the KDS button
3. Select Bosch
4. Label "Diskette 3.1" , insert it into the drive on request and confirm with "OK" (2x) --> Setpoint data is copied to the diskettes.
5. Insert setpoint data diskette 3.1 into the 3.1 floppy disk drive, insert operating system diskette 3.0 into the 3.0 drive.
6. Switch on the machine in the usual manner. IMPORTANT: When creating the KDS diskettes, all data on the diskettes used is overwritten. NOTE: In the event of an error, a corresponding message is shown and the program is cancelled completely. The procedure must be run from the beginning again and all data on the diskette will be deleted. A new diskette may have to be used.

12.1 Copying

1. Press the "C" button and select the vehicle to be copied.
2. Select the "Edit setpoint data" menu item from the special functions. Create a new vehicle in the usual manner. The setpoint values for the last vehicle selected will appear in the data input screen. Enter the data and save the data record.

12.2 Creating

1. Press the "C" button and select the "Edit setpoint data" menu item from the special functions. Create a new vehicle in the usual manner. An empty data input screen will appear. Enter the data and save the data record.

12.3 Editing

1. Factory-programmed setpoint data can neither be deleted nor modified. If this data does need to be modified, a new vehicle with modified setpoint data must be created. New vehicles created by the user are identified by a "+" in the selection menu. These vehicles can be deleted by the user using the "-" key or modified using the "< >" key. These keys only appear if vehicles have been entered by the user.

13.1 Customer-specific printer report header

The sub-item "Customer-specific text" must be called up in the "Special functions" menu. An input screen will appear on the monitor. This input screen must be filled out with the name and address and stored with the "S" screen key. The text entered is inserted into the report header.

13.2 Adjusting options

1. Call up the "Service" menu in the special functions ( "S" key).
2. Select the "Wheel toe adjustment" item or the "Camber adjustment" item from the "Adjustment" sub-menu. The toe and camber adjustment program will guide the user step by step through the adjustment using text and images. The measuring deviation for each measuring sensor will be shown on the screen when the adjustment has been completed.
3. You can store the adjustment values in the measuring sensor using the "Store" key or you can quit the program with the "Red dot key" without saving them (check). The adjustment values can be printed out.

13.3 Rotating plate test

1. Call up the "Service" menu in the special functions ( "S" key).
2. Call up the "Rotating plate" item in the "Service" menu. Turn the left-hand and right-hand rotating plate and check the display on the screen. Important The measuring range is ± 306 degrees.

13.4 Viewing and deleting customer entries from database

1. Call up the menu item "Delete" in the "Database" menu in the special functions. The data input screen will appear. Fill in the search fields with the data to be deleted.
2. Use the "-" button to delete this data record. A new data record can then be highlighted and deleted with the digital pen.
3. You can scroll through the entire database with the "Arrow up" and "Arrow down" keys.
4. You can quit the delete function by pressing the cancel key (red dot).

14. MODIFICATIONS WITHIN PROGRAM

Further modifications were carried out within the program which only slightly change the program sequence but which optimize the alignment in respect of comfort and speed. This is described below

1. Optimization of the rim run-out compensation in respect of speed.
2. Optimization of the steering routines: Highlighted values within the gate can still be corrected. The message "Rotating plates not connected" no longer causes the steering routine to be cancelled. Further measurements can be carried out after the rotating plates have been connected.
3. Standardization of screen colors with the colors on the tablet.
4. Addition of texts in several foreign languages.
5. Elimination of program-related and cosmetic faults.
6. Electronic water level.
7. Omission of kingpin inclination measurement.

15.1 Tire faults

TIRE FAULTS

15.2 Front axle faults

FRONT AXLE FAULTS

15.3 Rear axle faults

REAR AXLE FAULTS

Further details on the "Kinematic Diagnosis System" can be found in the operating instructions for the BMW KDS (Beissbarth / Bosch).

Functional and system descriptions are not subject to change. Parts availability and immediate ordering availability cannot be derived from this information. The specialist departments will be providing further details at the relevant time.