Haldex controller

CRC Performance HC MK3 PRO Haldex controller description




The CRC Performance HC MK3 PRO Haldex controller is a new development of our firm CRC Performance. The unit in question is a “Standalone” solution which enables to run vehicles retrofitted with a 4-motion drive train. It was our aim to develop a product which outclasses all steering which are currently available on the market. In months and months of development and countless kilometers driven, as well as cooperation with several quarter mile racing teams known in Germany, we have developed a steering which finally is a useful component also for quarter mile racing cars.

Of course, the CRC Performance HC MK3 PRO Haldex controller has got a racetrack mode enabling it to take an influence on vehicle dynamics and to adjust power distribution to the relevant speedway optimally.

Moreover, the Haldex controller is equipped with a dynamic street mode which is also completely new engineering by CRC Performance. Regarding performance, safety and equipping it is setting new standards. Also in communication between our Haldex controller and the rear axle differential we have been breaking the mold. As the first manufacturer/producer we can come up with a CAN-Bus Data communication. This nowadays absolutely essential technology makes it superfluous to convert or destroy the control unit located at the 4-motion drive train.

This primarily benefits operating safety.



Operating Modes


Off Mode

The Haldex controller is deactivated and by this, haldex clutch is completely open. The car responds in vehicle dynamics like a front wheel drive vehicle. Is the Haldex controller switched OFF, only boost pressure with max boost recall is shown on the display.


Street Mode

The locking level in street mode is programmed to a set level and depends on speed and boost pressure of front 95 %, back 5 % to front 50 %, back 50 %. Only by this it is warranted that for every driving situation there is optimum traction. Dynamic control makes it possible to gain speed, e.g. on wet roadway, because rear axle is being engaged even before boost pressure is build up. If speed increases, e.g. on an interstate, there is no necessity to supply much power on the rear axle. By doing this, locking level is reduced to 5 % on the rear axle with wide open throttle. Consequently, unnecessary frictional resistance is reduced as well as consumption. Letting go of the accelerator, and boost pressure falls below -0,5 bar, Haldex clutch is being opened completely and the vehicle responds like a front wheel drive vehicle.

Since the Haldex controller recognizes current speed via GALA speed signal, we defined several speed ranges. The processor recognizes one of those and adapts locking level in relation to the current boost pressure. The speed ranges have been set with due regard to power and gear transmission ratio of most vehicles retrofitted with 4-motion drive trains. In street mode, current locking level, speed and boost pressure are shown on the display.



If emergency brake is used or, to be more precise, stoplight switch is being activated, and by this, 4X4 drive is deactivated.



For dynamic control

Key data for dynamic control were collected during months and months of tests with several thousands of kilometers driven on a VW Corrado VR6 Turbo 4-motion with 474 PS / 640 NM. By this, all requirements concerning performance and safety on streets can be met.



Race Mode

The locking level in race mode can be adjusted from 0-100 % in steps of every 5%. This means that there is the possibility for maximum force distribution of 50 - 50%.

In difference to street mode, Haldex clutch in race mode is closed when reducing gas. By that, the vehicle has permanent four wheel drive regardless of boost pressure or speed. With the possibility to block the rear axle, behavior on the road changes drastically. Instead of understeering, as it is usually the case with 4-motion vehicles, the car can be brought to oversteer in a curve by quick load cycle changes. With this, even drifts are possible. This property is to be welcomed especially by weekend racers. In race mode, the set locking level is shown.



Haldex position ON/OFF

In race mode, there is the possibility to choose the tuning in the setup menu to activate the haldex clutch alternatively at 0 km/h or 20 km/h.

This answers the following purpose:

If Haldex controller is set on race mode and the Haldex clutch is closed, there is going to be tensioning in the drive train which will be noticeable in turning or parking. Unfortunately, this is due to technics in 4X4 vehicles and cannot be prevented well. We have found a possibility to activate Haldex clutch only at 20 km/h because in hobby-racetrack use, in most cases there are no starts with standing vehicles. In case there are any, you can activate race stand ON function and Haldex clutch is closed already at 0 km/h.



Quarter Mile Mode

Our quarter mile mode presents an absolute novelty in 4- motion sector. As first producer we can please the needs of 4- motion quarter mile vehicles. In the setup menu you can choose in steps of 5 km/h 0-375 km/h to adjust the locking level in steps of 1% 0-100%. This makes possible to take off from the start with 100% blocked rear axle and, gaining speed, 4X4 intensity can sink to 0%. It is possible to reach optimum traction without giving away power. Each vehicle has its relationship between weight and power, so onetime setting has to be done by the customer for every vehicle. Having finished setting, data are saved, but can be changed at every point in time, e.g. using other tires. The onetime driven curve can be increased or lowered by 50 % in 1% steps in setup menu. This makes quick and uncomplicated reaction to changes of the roadway like wet roadway, ground waves or pasted track possible. Optimum grip is always guaranteed without giving away power. By this mode, racing cars can make optimum use of the benefits of the 4X4 drive in quarter mile. At the start, full traction is guaranteed and at higher speed levels, frictional loss is reduced, resulting in higher terminal velocity. You will always be one step ahead of your competitors!

If emergency brake is used or, moreover, stoplight switch is being activated, Haldex clutch is opened and by this, 4X4 drive is being deactivated. When emergency brake is put on, burnouts are possible.






Cable harness

Cable harness is supplied with the Haldex controller. It can be plugged in individually for any type of car, e.g. at the rear axle differential or for the plug of the speed signal which is located at the gearbox. It is not necessary to cut off any plugs or something like that, because our Haldex controller controls the rear axle via CAN-Bus output signal. By that, no changes in the original Haldex electronics located at the rear axle differential are necessary. This is for the benefit that no parts will be definitely destroyed as it is the case in other all steering which are currently available on the market. Furthermore, the cable harness is equipped with a fuse. Installation Einbau is done in no time. Only power supply, boost pressure hose, emergency brake switch / stoplight switch and the plugs at the rear axle differential and speed sensor located at the front of the gearbox have to be plugged in. Additionally, wiring harness is equipped with a K-Line, which enables a diagnosis function of the rear axle.






The CRC PerformanceHC MK3 PRO Haldex controller is equipped with a 60 x 37 mm display, informs all the time about the most important parameters and leads you quickly and easily through all setup menus.

Blue displays with white indication or white displays with black indication are available.

The better readability of the white display is due to a wider viewing angle.



Display survey


Off mode – boost pressure with max boost recall is shown

Street mode – relevant locking level, boost pressure, oil temperature and speed

Race mode – locking level, boost pressure, oil temperature

Quarter mile mode – locking level

Main menu - relevant mode, boost pressure and Haldex oil temperature

Setup menu – speed- and quarter mile setup


Haldex oil temperature cannot be shown with all types of vehicles, because not every rear axle differential supports this function. This depends on the year of manufacture of the differential.






When implementing the Haldex controller for the first time, the speed signal of the gearbox can be tuned with the speedometer or GPS signal and the HC MK3 PRO Haldex controller and saved in a submenu. This is necessary for a precise tuning of functions relevant to speed. All settings remain unchanged even in case of loss of electricity, because they are saved in the processor.





CRC Performance HC MK3 PRO Haldex controller can be operated quickly, easily and intuitively only by rotary and pressure potentiometer (F-Drive operating device) and the large display. Setup menus are in the submenus so that they are not to be seen in operation mode. This makes a quick change of operation modes possible without maloperation.


Optional Equipment



Boost pressure gauge


The Haldex controller has a very effective boost pressure gauge. By making use of premium parts /units /components and measuring instruments/vehicle sensors for control and calibration of the sensors, this boost pressure gauge surpasses all currant analog displays concerning precision and reliability/operating safety by far. Additionally, the boost pressure gauge has an max boost recall you can delete whenever you want.



Oil temperature gauge/status display

Depending on the year of manufacture of the rear axle differential, current Haldex oil temperature is shown in the main menu. Oil temperature gauge has an max temperature recall

 you can delete whenever you want. With rear axles that do not support oil temperature function, current status of the Haldex clutch is shown. As long as emergency operation is not being activated in the original steering of the rear axle differential, the display shows Haldex OK. In case of activating the emergency operation, e.g. in exceeding temperature limit, Haldex

Error is shown and Haldex clutch is being opened completely.




Things to Know


Bauteileschutz Kennfeld

The rear axle differential of 4- motion vehicles has various means of protection to avoid damages in the gearbox caused by strain. If temperature rises above 100 °C, e.g. by lack of oil, protection map is being activated and Haldex clutch is being opened completely. As soon as temperature drops below 100 °C, Haldex clutch operates normally. In most cases, such temperatures are not to be reached on regular streets, nevertheless, preservation of such protection functions steered by the original steering which is located at the rear axle differential is very important.

As the Haldex controller HC MK3 PRO by CRC Performance does not mesh mechanically in the original rear axle (modification of the rear axle valve), all mechanisms of protection remain completely!





Boost pressure

Speed signal

Emergency brake switch / stoplight switch

power supply





F-Drive control


Haldex clutch

K-Line diagnostic

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