Traction Control

[grifjl]

We were sold a Sharan 1.9Tdi Sport last year (02 reg) and the dealer explained that the car had Traction Control.

 

Always wary of dealer comments I read the literature on the car and VW claim that traction control is part of the ABS system.

 

So, when it was icy last week I decided to give it a go and see whether it worked. In a word

[MrT]

I don't know on your particular model, but it certainly does exist. On mine if one wheel starts slipping, the brake is applied to it and there is the characteristic banging of the ABS as it tries to stop the wheelspin. There is also the EPS system that cuts in (seems to cut power) if you wheelspin whilst turning.

 

Anti-Lock Control - Traction Control

 

The traction control system is an expanded version of the anti-lock brake system. The system is integrated with the anti-lock brake system and uses the same wheel speed sensors and hydraulic control unit (HCU).

 

The HCU has additional internal solenoid valves incorporated to enable control modulation of the wheel brake pressures.

 

 

Brake Traction Control System (BTCS)

 

Brake traction control uses controlled braking of the spinning driving wheel, when the grip at the driven wheels are different.

 

The BTCS system is only active at road speeds up to 50 km/h (30 mph). When the system is active the driver is made aware of the fact by the illumination of a warning indicator located in the instrument cluster.

 

The spinning wheel is braked by the ABS system.

 

This transfers a greater proportion of the engine torque through the differential to the other driven wheel, thereby increasing the utilization of the available traction.

 

Anti-Lock Control - Stability Assist

 

The stability assist recognizes critical driving conditions, such as panic reactions in dangerous situations and stabilizes the vehicle by individually braking each wheel and engine control intervention without the need to a actuate the brake or the accelerator pedal.

 

The stability assist adds a further function known as Electronic Stability Program (ESP) to the Anti-lock Brakes (ABS) and Traction Control System (TCS). Whereas the ABS/TCS function controls wheel slip during braking and acceleration (longitudinal dynamics), the active yaw control stabilizes the vehicle about its vertical axis.

 

Sensors measure the position of the steering wheel, the pressure in the brake master cylinder, the yaw velocity (Yaw rate) and the acceleration transverse to the vehicle (Lateral acceleration). This makes it possible to compare the driver's intention with the momentary vehicle behaviour so that in the event of the vehicle becoming unstable the stability assist system can initiate the appropriate corrective action.

 

[seatkid]

I thought only the 2.8 V6 had traction control.. ;)

[Guest nimrod]

On VW's its an option across the range but is standard on the VR6

VW call it EDL, Electronic Differential Lock. the system uses the ABS sensors to monitor wheel speed, if a driven wheel increases speed (spins) the system brakes that wheel and transfers power to the non spinning wheel which has the better traction. The system works in both directions, forwards and reverse.

I say its available across the range but with further reading I find that it is not an available on the 1.8 2Ltr Turbo and the 1.9 TDI PD models when fitted with the tiptronic gearbox

[Dally]

With the Ford Galaxies, there are two types of traction control.

The first is the one comes part of the ESP system - this is standard on the V6 and I assume if any Galaxy is fitted with this option, it will have the traction control. This is a sophisticated poece of kit in that it controls both throttle and abs module to do its tricks.

The second is a less sophisticated traction control system called Brake Trcation control system. with this kit it uses just the brakes to control the slip that occurs when traction is lost. BUT this kit is only available on the 2.3 DOHC petro; engine.

 

Hope that helps grifjl

[vodkas]

Got a 4WD v6 auto. Traction control uses a viscous coupling between front and rear drives. If 1 wheel starts to spin, the power is diverted to the others. No electronics involved as far as i can see. Supposedly near impossible to wheel spin but does on muddy campsites if booted and on ice.

[Dally]

Vodkas

 

All above are talking about 2 wheel drive versions!

2 Wheel drive versions do not have a viscous coupling between the front and rear wheels because of this. This is why electronics are used to carry out this operation.