Automatic Transmission - Service Information BMW X5 E53

Scheme 468

Introduction

The 6-speed automatic transmissions were jointly developed by BMW and ZF (Zahnradfabrik Friedrichshafen).

1. See appropriate AUTOMATIC TRANSMISSIONS OVERVIEW article.

The automatic transmission is either standard or optional equipment (option 205).

So as to be compatible with the engines with higher torques, the automatic transmissions are designed with different strengths. The automatic transmissions thus differ, e.g. through different torque converters.

Depending on the engine fitted, the following 6-speed automatic transmissions are fitted

1. GA6HP19Z (designed for maximum torque of 420 Nm)
2. GA6HP26Z (designed for maximum torque of 600 Nm)
3. GA6HP32Z (designed for maximum torque of 750 Nm)

The automatic transmission requires 5 multi-plate clutches to shift between the 6 gears: 3 input clutches and 2 brake clutches.

Scheme 469

Brief Description Of Components

The automatic transmission consists of the following components

Mechatronics Module

The automatic transmission is controlled by the mechatronics module. The mechatronics module is a combination of hydraulic control unit and electronics module.

The hydraulic control unit is the hydraulic part of the transmission control system.

The electronics module contains the EGS control unit, the sensors and the electrical connections within the transmission. (EGS is the abbreviation for electronic transmission control).

Installation Location

The mechatronics module is a combination of hydraulic unit and electronics module. The mechatronics module is installed in the transmission oil pan.

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Scheme 477

How It Works

There are various other hydraulic valves within the hydraulic control unit in addition to the electronic pressure control valves and the solenoid valves listed (e.g. clutch valves, pressure reducing valves, etc.).

EGS Control Unit

The EGS control unit is a component of the mechatronic module. The data that the EGS control unit requires for shifting gears is sent on the powertrain CAN (PT-CAN) to the EGS control unit (e.g. injection period, engine speed, throttle valve angle, engine temperature and engine intervention). Within the mechatronics module, the EGS control unit directly actuates the solenoid valve and the electronic pressure control valves.

Selector Lever Position Switch

E53, E60, E61, E63, E64, E83, E87, E90, E91 The selector lever position switch and the hydraulic selector valve are both actuated by the selector lever via the Bowden cable. The switching pulses from the Steptronic are transmitted by the selector lever to the mechatronics module. The selector lever position switch consists of a slide with permanent magnet and 4 Hall sensors for the drive positions.

E65, E66 Only The mechatronics module is electrically actuated by the gear selector lever ("shift-by-wire"). Two Hall sensors in the selector lever position switch allow the position of the parking lock cylinder to be registered. Only when the parking lock is released can the gears be changed.

Sensor For Transmission Input Speed

The transmission input speed is measured at the transmission turbine wheel shaft (by a Hall sensor). The EGS control unit compares the transmission input and output speeds and from this calculates the shift time of the clutches. The EGS control unit adapts piston pressures to the clutches as necessary to compensate for different altitudes and differences in friction padding.

Sensor For Transmission Output Speed

The transmission output speed is directly proportional to the road speed and is measured by a Hall sensor on the transmission output flange. The EGS control unit accepts the speed and uses this, together with the load signals, to calculate the necessary gear changes.

Solenoid Valve

The solenoid valve in the hydraulic unit is actuated by the EGS control unit and has 2 functions (open and closed). The solenoid valve assigns the electronic pressure control valves to the corresponding release clutches, depending on the gear to be engaged.

E65, E66 only The parking lock is electrically actuated. Two additional solenoid valves are provided for the function of the parking lock. One solenoid valve actuates the parking lock valve, the other solenoid valve locks the parking lock cylinder.

Electronic Pressure Control Valve

The electronic pressure control valves (1-6) convert an electrical current defined by the EGS control unit into a proportional hydraulic pressure. The electronic pressure control valves actuate the valves belonging to the shift elements.

Two types of electronic pressure control valve are installed

1. Electronic Pressure Control Valves With Rising Map
2. Electronic Pressure Control Valves With Falling Map

Scheme 478

For E53, E60, E61, E63, E64, E87, E90, E91

The selector lever has the positions

1. P Park
2. R Reverse gear
3. N Neutral
4. D Drive (= automatic mode)
5. M/S M for manual mode = Steptronic, S for sport program = automatic mode with sporty map

The selector lever position display is located in the selector lever trim.

The operation of the selector lever is described in the Owner's Handbook.

The selector lever is installed in the centre console. The selector lever trim holds the illuminated display for the selector lever position.

Construction

The gate pattern diagram is located in the selector lever trim. The drive position selected is illuminated in the gate pattern diagram. The background lighting is actuated by the sliding contact on the selector lever. Using the Steptronic switch, gears can be shifted up and down manually.

Scheme 479

Scheme 480

The following positions can be selected with the selector lever

1. P Park
2. R Reverse gear
3. N Neutral
4. D Drive (= automatic mode)
5. M/S Sport program or manual mode (Steptronic)
6. Manual downshift
7. + Manual upshift

A lock prevents the selector lever from being inadvertently moved to positions "R" and "P". To overcome the lock, the button on the front of the selector lever knob must be pressed.

Plausibility Check

The selector lever can only be moved from position "D" to the "M/S" shift gate. For this shift to be carried out, the EGS control unit must detect the M/S shift gate and position D signals at the same time. The signals "+" or "-" for upshift and downshift are only recognised in the manual shift gate.

For E65, E66

The gear selector lever has the positions

1. P Park
2. R Reverse gear
3. N Neutral
4. D Drive (= automatic mode)

The selector lever position display is located in the instrument cluster.

The operation of the gear selector lever is described in the Owner's Handbook.

Steering Wheel With Buttons For Sport Program And Manual Mode

1. E65, E66 The steering wheel has a button for selecting the program. The following drive programs can be selected in a predefined sequence: Sport program, manual mode or automatic mode. The steering wheel also houses the buttons for changing up and down in manual mode. Program selection and control in manual mode are described in the Owner's Handbook.

Instrument Cluster Display

The drive ranges and drive program are displayed in the instrument cluster, the signal required for this is sent from the electronic transmission control.

E53, E83

On the E53 and E83, the vehicle electrical system is classified into the high-level version or the basic version.

Only 2 warnings (overheating and emergency program) are displayed.

1. Vehicle electrical system, High version Warnings are only given with text.
2. Vehicle electrical system - Basic version Warnings are only given with symbols.

E60, E61, E63, E64, E87, E90, E91

Check-Control messages appear with a (red or yellow) symbol in the LCD. The following Check-Control messages can be shown

1. Transmission too hot or overheating (yellow or red symbol)
2. Selector lever position P not engaged (yellow symbol)
3. Emergency program, transmission fault (yellow or red symbol)

E65, E66

Check-Control messages appear with text and a symbol in the LCD display.

CID: Central Information Display

1. E60, E61, E63, E64, E87, E90, E91 The CID displays detailed information about the Check-Control messages in the instrument cluster. The instrument cluster controls these messages on the K-CAN (body CAN).

In addition to the visual display, the Check-Control system also alerts the driver with acoustic signals. Depending on the importance of the associated message, a single or double gong of variable volume and tone will sound. The instrument cluster controls these warnings by means of the K-CAN. The acoustic warnings are emitted by the MASK (multi-audio system controller).

CD: Control Display

1. E65, E66 The Control Display is the central display for the information and communication system. The Control Display serves as the interface between the MOST and K-CAN data buses. (MOST = "Media Oriented System Transport"; K-CAN = body controller area network".) Amongst other things, detailed information about the Check-Control messages in the instrument cluster are displayed on the Control Display. The instrument cluster controls these messages on the K-CAN (body CAN).

The electronic transmission control needs signals from the following components

Brake Light Switch

The signal from the brake light switch is needed for the function of the selector lever lock and the adaptive transmission control.

DME or DDE: Digital Engine Electronics Or Digital Diesel Electronics

The DME or DDE sends messages about the current operating status of the engine to the EGS (e.g. engine speed or torque).

The EGS reports the current operating status of the transmission back to the DME or DDE.

DSC: Dynamic Stability Control

The DSC optimises both driving stability when pulling away or accelerating and traction. Within the limitations of the laws of physics, DSC compensates for driving conditions such as oversteering/understeering. As part of this process, dynamic driving signals (e.g. wheel rotation speed, lateral acceleration) are sent to the DSC control unit. DSC transmits the processed signals regarding cornering, acceleration and winter detection to the EGS control unit.

Accelerator Pedal Module

The signal from the accelerator pedal module is needed for the adaptive transmission control.

JBE: Junction box electronics

1. E87, E90, E91 The JBE is the data interface (= gateway) between the K-CAN and the PT-CAN. Signals from the F-CAN are simply looped through.(K-CAN = body CAN; PT-CAN = powertrain CAN; F-CAN = chassis CAN.) The junction box consists of the JBE and the power distributor. The power distributor provides power, amongst other things, for the gate pattern diagram and the EGS control unit.

KGM: Body Gateway Module

E60, E61, E63, E64 from 09/2005 From 09/2005, the vehicle electrical system has been modified.

The body gateway module (KGM) supersedes the SGM. The KGM is the data interface (= gateway) between the K-CAN and the PT-CAN. (K-CAN = body CAN; PT-CAN = powertrain CAN.) The diagnosis wire is connected to the KGM.

SGM: Safety And Gateway Module

1. E60, E61, E63, E64, E65, E66 The SGM is the data interface (= gateway) between the K-CAN, byteflight and the PT-CAN. (K-CAN = body CAN; PT-CAN = powertrain CAN.)

System functions

The automatic transmission has the following system functions

1. Adaptive Transmission Control
2. Overlap Control
3. Starter Inhibitor
4. Parking Lock
5. Warming-Up Program
6. Engine Intervention
7. Downshift Inhibitor
8. Reverse Gear Inhibitor
9. Selector Lever Lock (Shiftlock)
10. Standstill Decoupling
11. Interlock
12. Emergency Program
13. Rock Free From Snow Function

Adaptive Transmission Control

As with earlier automatic transmissions, the 6-speed automatic transmissions offer the choice between a comfort program and a sport program.

The adaptive transmission control (component of electronic transmission control) adapts the shift characteristics of the comfort program and sport program to the driver's wish and the driving situation.

In both programs, the adaptive transmission control changes from a basic map to a performance-orientated map, as required

1. Comfort Program In Selector Lever Position "D" The comfort program is based on 2 characteristic maps: The XE map (extreme economy) and the E map (economy). The EGS control unit normally selects the economical XE map (= basic map). In case of particular demands (e.g. load requirements), the system will change to the performance-orientated E map. If the input signals change in favour of a more gentle driving style, the system will change back to the more economical XE map.
2. Sport Program In Selector Lever Position "M/S" The sport program effects dynamic, sporty shift characteristics. In the sport program, there is the basic S map (sport) and the performance-orientated XS map (extreme sport). If an extremely dynamic driving style is called for, the system will change from the S map to the performance-orientated XS map.

The adaptive transmission control takes the following demands into account

1. Adaptation To Driver Type
2. Driving Uphill Or Trailer Towing
3. Driving Downhill
4. Braking Deceleration And Automatic Upshift
5. Winter Program

Adaptation To Driver Type

The adaptation to different driver types is done using the following values

1. Kick-fast If the accelerator pedal is depressed rapidly, the shift program is changed accordingly. This is achieved by the detected accelerator-pedal value being compared with threshold values in the EGS control unit. The result of this comparison is the proposal of one of the two possible programs (XE or E in comfort program, S or XS in sport program).
2. Cornering detection Cornering detection reacts to the vehicle's lateral acceleration with an indirect adaptation to the driver type. Lateral acceleration is considered an indirect statement of the preferred driving dynamics and does not cause an immediate gearshift response (shifts when cornering could adversely affect driving stability). Lateral acceleration is calculated from the signals from the wheel-speed sensors, from the yaw rate and road speed.
3. Brake evaluation The braking action is evaluated in a similar way to kick-fast. The braking deceleration is measured and compared with threshold values in the EGS control unit. The result of this comparison is the proposal of one of the two possible programs (XE or E in comfort program, S or XS in sport program).

The driver-type adaptation is restarted each time the vehicle pulls away from a standstill.

Driving Uphill Or Trailer Towing

These functions are based on a comparison of actual car acceleration with a nominal value. From the current engine operating situation, the acceleration with normal load on a level surface is calculated. If the actual acceleration is significantly below the theoretical value, the driving uphill or trailer towing function is activated.

The corresponding shift characteristics allow a high-rpm driving style. Undesirable upshifts and frequent up/downshifts are eliminated or greatly reduced.

Driving Downhill

If the EGS control unit detects downhill driving, it will automatically shift down a gear as the vehicle's speed picks up. This enhances the engine's braking effect. A downshift is only effected if the engine speed is below the maximum speed of the lower gear.

The EGS control unit detects downhill driving on the basis of signals from the throttle valve potentiometer (load), wheel speed sensor (road speed) and brake light switch (brake activation).

Braking Deceleration And Automatic Upshift

To decelerate the vehicle, the foot is taken off the accelerator pedal and the brake depressed as necessary. The gearshift map triggers an upshift when the throttle is closed. These gearshifts are not necessary in conjunction with brake applications as they prevent the engine's braking effect from being exploited.

The intention to apply the brakes can often be anticipated from the accelerator pedal being rapidly released to the zero position. If such an action is detected, the upshift is suppressed for as long as the accelerator pedal is in the zero position and the vehicle is in overrun mode.

Winter Program (Only With Selector Lever In Position D)

The winter program is automatically activated if the drive wheels start to spin even at a low rate of acceleration. The winter program ensures better traction by not using 1st gear. Early upshifts reduced the reactions caused by load changes. The winter program is deactivated if the wheels do not spin for several seconds despite high drive torque.

Overlap Control

Overlap control provides gentle shift characteristics as follows: With overlap control, several multi-plate clutches are in use at the same time. Here, pressure is reduced in the active multi-plate clutch and at the same time built up in the clutch that is about to be activated. The reduction and build-up of pressure is maintained until a synchronized speed is reached. At this point, the hydraulic pressure for the multi-plate clutch to be activated can be built up completely. Overlap control is active for all gearshifts from 1st to 6th gear and from 6th to 1st gear.

Starter inhibitor

It is only possible to start the engine when the selector lever is in position "P" or "N".

1. E53, E83 The EWS (electronic immobilizer) evaluates the following signal from the EGS (electronic transmission control) for the engine start: Selector lever position P or N as signal via direct wire
2. E60, E61, E63, E64, E65, E66, E87, E90, E91 The CAS (Car Access System) evaluates the following signals from the EGS (electronic transmission control) for the engine start: Selector lever position P or N as CAN message via the powertrain CAN Selector lever position P or N as signal via direct wire In principle, the CAN message is used. If the message is incorrect or invalid, it switches to the signal from the direct wire.

Parking Lock

The parking lock locks the transmission output shaft. The vehicle is prevented from rolling unexpectedly. The parking lock is designed to provide a reliable brake on gradients up to 32 %.

1. E53, E60, E61, E63, E64, E87, E90, E91 When the vehicle is stationary, the parking lock is engaged purely mechanically via the selector lever (Bowden cable from selector lever to mechatronics module).
2. E65, E66 With the electric version of the parking lock, the parking lock is applied and electrically secured via a mechanical spring system in the transmission.

The parking lock is activated under the following conditions

1. Pressure on the button on the gear selector lever and road-speed signal less than 2 km/h.
2. Remote control removed from the insert compartment and road-speed signal 0 km/h.
3. Engine ON and Transmission position "D", "N" or "R" and Driver's door open and Driver's seat not occupied, (road-speed signal less than 2 km/h).

The parking lock is only released when the engine is ON. Reason: Only when the engine is ON is there enough hydraulic pressure to open the parking lock (mechanical emergency release possible).

If the parking brake (EMF = electromechanical parking brake) fails, the parking lock can still be applied.

Example: A fault in the system prevents the parking brake from being moved from "Hold" to "Park". In this event, the EGS control unit will apply the parking lock after performing a plausibility check.

The locking conditions are as follows

1. Selector lever in position "N"
2. Speed 0 km/h
3. Engine OFF and ignition OFF

WARMING-UP PROGRAM

The warming-up program is activated after each engine start with the engine temperature lower than approx.60 °C. In the warming-up program, the automatic transmission remains in the performance-orientated map XE or XS up to a certain temperature. Gearshift are only executed at higher speeds. This enables the engine and the catalytic converter to reach their operating temperatures more quickly.

Up to a transmission oil temperature of approximately 35 °C, the converter lockup clutch is neither controlled nor closed.

Engine Intervention

During the gearshift, the EGS control unit emits signals to influence the digital engine electronics (DME) or digital diesel electronics (DDE).

The DME then retards the ignition timing for a few milliseconds.

The DDE reduces the fuel quantity for a few milliseconds by reducing the injection period.

This action briefly reduces the torque, improves shift quality, reduces the load on the transmission and shortens the shifting time.

Downshift Inhibitor

A downshift inhibitor prevents the transmission shifting to a lower gear until the engine speed is below the maximum speed for the next gear down. The engine speed signal is transmitted by the DME/DDE to the EGS control unit.

The downshift inhibitor prevents damage to the engine and transmission.

Reverse Gear Inhibitor

The reverse gear inhibitor electronically prevents reverse gear from being engaged when the vehicle is moving forwards at speeds above 5 km/h (3 mph). When this road speed is exceeded, the corresponding solenoid valves are no longer actuated. This prevents multi-plate clutches B and D (for reverse gear) from being charged.

Selector Lever Lock (Shiftlock)

E53, E60, E61, E63, E64, E87, E90, E91 The selector lever is locked in positions "P" and "N" by an electromagnet. The electromagnet is actuated by the EGS control unit. The selector lever lock is engaged when selector lever position P or N is detected and the ignition (terminal 15) is ON.

1. Position change from selector lever position "P" or "N": A position change is only possible at road speeds of less than 5 km/h and if the brake is applied at an engine speed of less than 2500 RPM.

Standstill Decoupling

The standstill decoupling of the torque converter decouples the torque converter from the drive when the vehicle is at a standstill. Thus only a minimum load remains, and the fuel consumption is reduced. The decoupling is effected by clutch A within the transmission being regulated (depending on the load signal and output speed).

Interlock

1. E53, E83 and E60, E61, E63, E64 up to 09/2005: The ignition lock is mechanically linked to the selector lever by a Bowden cable (as on the E38). The interlock only allows the ignition key to be removed when the selector lever is in position P. Conversely, the selector lever can only be moved from position "P" when the ignition key is in the ignition lock and turned at least to ignition ON.
2. E65, E66: The remote control can only be removed when the CAS registers a road-speed signal of less than 1 km/h. If the remote control is removed from the insert compartment after the engine has been switched OFF, the parking lock will automatically be applied.
3. E87, E90, E91 and E60, E61, E63, E64 from 09/2005: The selector lever is locked in position P by an electromagnet when terminal 15 is OFF. When the remote control is not in the insert compartment, the selector lever is locked in position P. When terminal 15 is activated, the EGS control unit applies current to the electromagnet and the selector lever is released. A microswitch registers the locking or unlocking of the selector lever. The microswitch transmits a signal to the CAS (Car Access System) to enable the remote control. Interlock without convenience access If the selector lever is not engaged in position P, the remote control cannot be removed from the insert compartment. The selector lever is locked when the selector lever is in position P and the ignition is OFF. The remote control can be removed. Interlock with convenience access The engine and terminal 15 (ignition) can only be switched off when the selector lever is in position P.

Emergency program

The emergency program is activated if the transmission management should fail or detect a malfunction that could lead to critical driving conditions. In the emergency program, the vehicle remains operational, albeit with limitations.

If the electronic transmission control fails (without current), the following forward gears can be engaged

1. Failure In 1st-3rd Gear -> Emergency 3rd Gear
2. Failure In 4h-6th Gear -> Emergency 5th Gear
3. A Restart Will Be Performed In 3rd Gear.

Rock Free From Snow Function

To rock the vehicle free from snow, it is possible to shift between selector lever positions "D" and "R" without the selector lever lock (effective in "N"). With the engine running, the gearshift must be completed within 0.5 seconds.

Operation

The operation of the 6-speed automatic transmission is described in the Owner's Handbook.

Notes for service staff

Service staff should note the following points

1. Service notes: Refer to «GENERAL INFORMATION FOR SERVICE STAFF ABOUT THE 6-SPEED AUTOMATIC TRANSMISSION: E53, E60, E61, E63, E64, E65, E66, E83, E87, E90, E91»(/bmw/x5/e53-1999-2003/remont/automatic-trans/#automatic-transmission-service-information__general-information-for-service-staff-about) .
2. Diagnosis
3. Encoding/programming
4. Car & Key Memory: - E87, E90, E91: Almost all Car & Key Memory functions are programmed inside the vehicle itself. (See "Personal Profile" in the Owner's Handbook: individual settings for a maximum of 3 remote control units via the display in the instrument cluster or via the Central Information Display)

Subject to change.

General Information For Service Staff About The 6-Speed Automatic Transmission: E53, E60, E61, E63, E64, E65, E66, E83, E87, E90, E91

The following general information about the automatic transmission is provided for service staff: - Oil change - Interlock emergency release (E87, E90, E91 only) - Parking lock emergency release (E65, E66)

Oil Change

Interlock Emergency Release

E60, E61, E63, E64 from 09/2005 > E87, E90, E91

In an emergency, the selector lever can be moved by pressing the interlock locking pawl out of selector lever position "P". The selector lever cover must be removed for this emergency release.

Scheme 481

Parking Lock Emergency Release

E65, E66 If the parking lock can no longer be released hydraulically, a mechanical emergency release device is still possible. This allows the vehicle to be pushed or pulled if necessary.

Scheme 482

See also:
• GENERAL INFORMATION FOR SERVICE STAFF ABOUT THE 6-SPEED AUTOMATIC TRANSMISSION: E53, E60, E61, E63, E64, E65, E66, E83, E87, E90, E91