D2 S8 setting off in second gear?

[spannerrash]

hello all
In almost 18 months of ownership I have only covered aprox 500 mls in my D2 S8. It's been a bit of a resto project. On a couple of occasions, when pulling away at traffic lights, it seems to pull away in second gear. Is this a normal function of the gearbox DSP selecting a smooth set off reflecting my sedate driving style or is this the start of a potential problem.

Thanks all in advance

[David's8]

Does it then operate normally with no clunks? No indication of it being in limp mode? (Such as "PRDNS" illuminated which can sometimes be triggered by selceting reverse for some reason). I would suggest you scan it with VCDS to check if there are any indications there pointing towards a F125 switch problem. My F125 problems started off with a similar issue i.e. incorrect gear selection when pulling away.
Also, take it out for a long, sprightly drive - these cars need to be used!

[The_Laird]

Also, take it out for a long, sprightly drive - these cars need to be used!



Now, when David says “sprightly”’ he probably means a good deal quicker than you and I might interpret the word! :)

[awolfinsheepsclothes]

If my old memory is correct, it's normal after sedate driving if you don't come to a complete stop and accelerate gently for the gearbox to stay in second gear. i think it says this in the owners manual also check your kickdown switch they are almost always turned off.
Dave

[spannerrash]

Thanks for the replies everyone.


I have VCDS and there are no reported transmission faults. Car has done this maybe 3 times. There are no clunking noises at all and shifts seem pretty smooth. No fault indicator lights on the transmission indicator. The issue only happens when I am already at a complete stand still, traffic lights etc. The last time this happened was whilst having a fairly steady drive to work some nob pulled along side me at some traffic lights, clearly intending to cut me off as the lanes went from 2 to 1. Car was in drive, I moved lever to tip mode to check what gear was displayed on the dash. According to that we were in first. I put back to drive ready to set off (not sport mode). On setting off it was clear she wanted to take it steady. I was left looking like the guy who took the moral high ground and let the other guy in. On this occasion, I didn't want to be that guy. Push further on the throttle and she changes down and away we go.

Car has only done 87000 mls and gearbox oil and strainer have been changed recently.

My gut feeling is that this is normal after periods of smooth driving. Also bear in mind that I disconnect the battery quite often whilst working on the car so maybe the car has had no time to learn my driving style.

What I was hoping is that you guys would tell me this is normal and you have all experienced this when driving steady. If that's not the case than clearly she is doing something unusual and thus a potential future problem.

MAF meter likely to have any influence over this?

[moltuae]

Thanks for the replies everyone.


I have VCDS and there are no reported transmission faults. Car has done this maybe 3 times. There are no clunking noises at all and shifts seem pretty smooth. No fault indicator lights on the transmission indicator. The issue only happens when I am already at a complete stand still, traffic lights etc. The last time this happened was whilst having a fairly steady drive to work some nob pulled along side me at some traffic lights, clearly intending to cut me off as the lanes went from 2 to 1. Car was in drive, I moved lever to tip mode to check what gear was displayed on the dash. According to that we were in first. I put back to drive ready to set off (not sport mode). On setting off it was clear she wanted to take it steady. I was left looking like the guy who took the moral high ground and let the other guy in. On this occasion, I didn't want to be that guy. Push further on the throttle and she changes down and away we go.

That sounds to me like the common brake pedal switch problem. It's not actually setting off in a higher gear but limiting the throttle response because it thinks you still have your foot on the brake pedal. It's likely that you just need to adjust or replace your brake pedal switch.

[spannerrash]

Hi Moltuae

Thanks for your response.

You may have something here because when I try to do a flying start from standstill, I tend to hold the car with my left foot on the break and right foot hovering over the throttle. Maybe I am hitting the throttle before releasing the break and thus maybe causing the issue you have listed above. I'll stop with the left foot breaking and see how it goes.

Thanks for your help everyone, much appreciated.

[moltuae]

Hi Moltuae

Thanks for your response.

You may have something here because when I try to do a flying start from standstill, I tend to hold the car with my left foot on the break and right foot hovering over the throttle. Maybe I am hitting the throttle before releasing the break and thus maybe causing the issue you have listed above. I'll stop with the left foot breaking and see how it goes.

Thanks for your help everyone, much appreciated.

I had exactly the same symptoms when I had trouble with my brake pedal switch. It would usually happen at traffic lights and, I think, more commonly following firm/heavier braking (for example, when the lights suddenly change and you decide to stop rather than go through). To diagnose it, you could try holding it on the handbrake (and dropping it in to neutral if necessary) while you're waiting for the lights to change.

There's one or two threads about the brake switch here somewhere. From memory, I believe there are two sets of contacts, one which is supposed to make/release before the other. If the timing of those contact openings/closures is not correct, it seems the ECU (the ESP ECU I assume?) limits the throttle.

[spannerrash]

Thanks for the info Mark.

I'll alter my driving style at the traffic lights for a while, see how that goes but ultimately will probably just buy a new switch and swap it. Already spent a fortune on the car so no point in getting cheap now.

Cheers Frank

[steamship]

Thanks for the info Mark.

I'll alter my driving style at the traffic lights for a while, see how that goes but ultimately will probably just buy a new switch and swap it.

If it isn't your driving style, then don't just buy a new brake switch. As Mark mentioned, the switch may just need adjusting by half a turn or so, and you use VCDS to set it.

EDIT: Just found the thread Mark was referring to. It's a pretty long one, but start from here:

http://forum.a8parts.co.uk/showpost.php?p=124323&postcount=285

and also check post #288.

[HPsauce]

It's been said above, but my very first thought was adjust the brake pedal switch. :cool:

You can monitor it with VCDS and see just how "hair trigger" the 2 separate sensors are.

I adjusted mine, but it still occasionally does the same thing. Next time I have all the gubbins out of there I'll give it another turn or two.
Sadly that will probably be fairly soon as I have an issue with my DVB-T wiring which is all buried in the same area, behind the drivers knee panel. :tuttut:

Basically there are two switches in one with very slight difference in the operating position. One works the brakes lights, the other informs the ECUs.
It is very possible to have the pedal released, brake light off, no braking force BUT the ECUs are still being told the brakes are on, with strange sluggish behaviour the result until some minor jolt or vibration regularises everything.
It is of course not a fault, just normal operation, so nothing gets recorded.

[spannerrash]

Thanks for the response everyone.

I think we can bring this post to a close at this point.

I have altered my driving technique this last month or so and have had no further occurrences. I did purposely hit the throttle on one occasion slightly before releasing the brake and the slow acceleration was replicated.

Perhaps the brake switch may be a little sensitive and need adjusting but at the moment I'll just carry on as I am and monitor the situation.

Thanks for all your support.