gg117

The ESP symbol light started flashing the other day for about 3 seconds, then stopped. It happenned during acceleration from a near stop. The car didn't feel like it was accelerating properly as well. The engine rpms increased to about 3500, but the car was not pulling as hard as one would expect. It felt as if something was holding it back. I've noticed this on other occassions as well, but this is the first time I saw the ESP light flash. What's the advantage of keeping ESP active, can I simply disable it by hitting the button on the dash? Does it sound like the ESP function is malfunctioning and some how holding back the horsepower from reaching the wheels?

skiracer

kind of the reverse of ABS. If the wheel sensors are malfunctioning, then the ESP could be actuating when it's not needed, slowing you down. Pull any DTCs from your car using Vag-Com and see if it reports any relating to the ABS sensors or the ESP system.

This stolen from www.fast-autos.net:

"All Audi S8s are fitted with the electronic stability program (ESP) as standard. ESP continually monitors the parameters critical for the maintenance of the car's stability and intervenes automatically if there is any risk that it might skid. The ESP control unit calculates the momentary state of the vehicle from the wheel speeds and data supplied by the anti-lock brake system (ABS), the traction control system (ASR), and by sensors that detect the steering angle, yaw moment and lateral acceleration. Using this information it can then initiate any countermeasures deemed necessary.

ESP counteracts oversteer by selectively braking the front wheel on the outside of the bend, while in the case of understeer, it briefly brakes the rear wheel on the inside of the bend. The combination of permanent four-wheel drive and ESP makes the Audi S8 one of the safest cars on the market."

You could turn off the ESP until the problem is resolved without causing any real problems (as long as you aren't pushing the envelope)!!

gg117

upon exiting a turn. I can't imagine that I was pushing the car hard enough to activate the ESP. Will simply getting on the gas pedal 1/2 or more throttle upon exiting a corner activate the system? I'll do some more road testing myself to test. I recently had the car at the dealer and no trouble codes were reported, so I don't suspect there are any because I recall experiencing this problem before bringing it it. Also, does the light always flash when the ESP system is activated?

gg117

activates under what I would consider hard, but normal braking conditions, under dry conditions. Is my interpretation of "normal driving" possibly too aggressive, or can the ABS sensors be too sensitive?

GrA8ful S8

You want the light to flash?? Keep your sumer tires on in the snow, and floor it!!! ;-)

GrA8ful S8

...I endured last winter with my Dunlop sp8000's, what an experience, I had 2 pirelli snowsports, (I got the last two on tirerack.com, and I could not find 2 more of them ANYWHERE, so I had 2 snowtires sitting in my basement all winter while I was sliding around.....needless to say, I have the other two now, and am getting ready to mount them ALL on soon!!)

dimitristx

There have been only 2 occasions that I've had the S8 activate ABS. In both situations it was a slippery tarmac and an emergency brake. Under normal, dry conditions, the S8 brakes are very difficult to "lock".

skiwi

1) reduce engine power upon detection of wheel spin, and
2) use the individual wheel brakes to attempt to transfer torque from a spining wheel to it's slower spinning brother on the other end of the axle.

esp will not *stop* a wheel spinning, it will endeavour to improve the torque to the other wheel to aid traction.

the version in the s8 also uses stability management to selectively brake a wheel to limit oversteer or understeer.

from what you describe, the system is interveening normally. however often you notice what is causing traction loss. clearly you didn't in this case.

skiwi

if you want to improve braking, have a look at the condition of your shocks....

also tyre condition obviously....

gg117

Is it possible that ESP and ABS are triggering prematurely because of some malfunction given that there are no trouble lights illuminated and a recent visit to the dealer did not reveal any trouble codes? If not I'll have to assume that it's my aggressive driving style that's caused these systems to activate.

One final note, I have new Conti tires and the car as 60k, so I don't suspect, nor notice, anything indicating that my shocks are not functioning properly.