Strange engine fault??? No fault code

[S3 Hilife]

Hi guys, wonder if anyone can shed any light on this little one, for last couple of months when setting off quickly in 1st gear the car cuts all power for a split second after setting off when revs picking up and I have seen out of corner of my eye an orange light flash on for a split second but cant confirm if its the EML (probably is)
its done this a few times now over last couple of months and I cant seem to figure out whats causing it, oh and no fault codes whatsoever for engine whenever I scan with VCDS

Steve

 

[Jenno007]

Is this when you are going in a straight line or turning?

I'm guessing the orange light you see is the traction control light, which then cuts the power

 

[S3 Hilife]

Always seems to be when in a straight line when setting off but only when setting off quickly

Steve

 

[Jenno007]

I get the exact same thing but only when turning and accelerating in first gear, usually out of a driveway

Turn off your traction control and see if it happens again, I'm guessing it wont. Out of curiosity do you have any issues with your haldex at all? Ie, feel the wheels dragging on tight lock?

 

[S3 Hilife]

I'll try keeping the TC off for a while, haven't noticed anyother problem tho

Thanks mate, I'll give that a try

Steve

 

[S3 Hilife]

Any ideas what could cause this and not throw up a code?
I think I remember reading a post of yours Jenno007 a little while back about this, was it you?

 

[Jenno007]

The reason this isn't throwing a code is because it's the traction control thinking the wheels are spinning and cutting power.

Maybe one of the wheel speed sensors is faulty. Or I imagine that this happens when you pull out of a driveway and have the wheels turned, meaning that the wheels aren't all spinning at the same speed, so traction control kicks in. I'm just guessing though

 

[S3 Hilife]

Yep, that makes sense now, I did have a OSF wheel speed sensor fault a while back (couple of times) but at the time it didn't seem to affect anything and I havent seen that fault for months.
Thanks for your help with this, I think i'll just replace that sensor

Steve

 

[Jenno007]

No worries mate. Remember I'm no mechanic but that does sound like what it will be

 

[<tuffty/>]

ESP uses the ABS sensors to detect wheel spin... if you have a fault in the ABS (sensor or wiring etc) it will affect the ESP... as Jenno said the symptoms you describe suggest the fault in the ABS is confusing ESP into operating...

For ESP to work properly the steering wheel needs to be on correctly too... alot of peeps get wheel alignments and end up with the wheel off centre when driving straight... there is a steering angle sensor that works with the ABS sensors so the ESP knows that the speed difference between the front wheels while turning is normal operation...

<tuffty/>

 

[S3 Hilife]

I just hast had wheel allignment done last weekend after replacing my fromt suspension, could this have affected it?

 

[<tuffty/>]

is the steering wheel on straight as you drive?

<tuffty/>

 

[Jenno007]

Well as Tuffty said, when you are driving in a straight line, is your steering wheel perfectly straight?

edit: DOH

 

[S3 Hilife]

Yep, its perfectly straight, but it has been doing this for a while now

 

[S3 Hilife]

Would it not throw a code if this was the case tho?

 

[<tuffty/>]

Its not a fault with ESP or the ECU/Engine... its an issue derived from a fault in the ABS... the ABS has a fault and as a consequence the ESP is doing as its told... its not faulty because of that just symptomatic

<tuffty/>

 

[S3 Hilife]

Its not a fault with ESP or the ECU/Engine... its an issue derived from a fault in the ABS... the ABS has a fault and as a consequence the ESP is doing as its told... its not faulty because of that just symptomatic

<tuffty/>

Thanks tuffty, so still likely the wheel speed sensor or have I missed the point there.

Steve

 

[<tuffty/>]

Thanks tuffty, so still likely the wheel speed sensor or have I missed the point there.

Steve

Yep.... its most likely the speed sensor... rescan and post up the actual code though...

<tuffty/>

 

[S3 Hilife]

Yep.... its most likely the speed sensor... rescan and post up the actual code though...

<tuffty/>

Thanks will do, I havent seen that code for maybe a month or so but it was OSF wheel speed sensor intermittant fault (or something to that effect) i'll dig the printout sheet later and post the actual fault

Thanks to both of you

Steve

 

[Essflee]

The traction control is renowned for cutting in on quick getaways, if this is the only time it happens then there is no fault, be lighter on the throttle or if you want to accelerate quickly from standstill then turn the esp off briefly.

 

[S3 Hilife]

The traction control is renowned for cutting in on quick getaways, if this is the only time it happens then there is no fault, be lighter on the throttle or if you want to accelerate quickly from standstill then turn the esp off briefly.

Yeah but its so annoying if you want to get away quickly and need power and the damn thing cuts out, there must be an easier way of pinpointing the cause

I found the print out from a couple of months ago with the speed sensor fault, I havent seen it for a while though
00285

Thanks

 

[Essflee]

It used to be annoying yeah, It's like an automatic response now, when I know I'm going to accelerate hard from standstill I just turn off the esp.

Saps all power otherwise.

 

[<tuffty/>]

I coded ESP out altogether... its a right PITA to remember to switch off (although it was second nature after a while) but when I forgot it would always catch me out...

that fault code will be why your ESP cuts in while turning... I had the same issue on my A2... I replaced the sensor and all was good again

<tuffty/>

 

[S3 Hilife]

It used to be annoying yeah, It's like an automatic response now, when I know I'm going to accelerate hard from standstill I just turn off the esp.

Saps all power otherwise.

Lol, I've got to get in the habbit of switching it off more often then, it just seemed strange cos I never had a problem with it untill last couple of months, I'll have to do what tuffty did and switch it out altogether

Steve

 

[S3 Hilife]

I coded ESP out altogether... its a right PITA to remember to switch off (although it was second nature after a while) but when I forgot it would always catch me out...

that fault code will be why your ESP cuts in while turning... I had the same issue on my A2... I replaced the sensor and all was good again

<tuffty/>

Haha, i was writing my reply as you posted this lol

 

[Essflee]

Not sure when you had your car mapped but a remap definitely causes the esp to kick in more often on quick launches.

 

[S3 Hilife]

Within the last year, cant remember exactly when but is only stage1 Revo at moment.

I think i'm going to change the speed sensor as it poped up a couple of times, never done one on one of these, do they often need to be cut and drilled out?