Tiptronic issue after tyre change
Discussion
2003 Boxster 2.7
I had a puncture in one of my front tyres this week. I replaced the damaged tyre with a new one. This seems to have caused some tiptronic problems. The box works fine in manual, and it will change up and down in auto, however, it does not change to 5th gear once it has been forced down by the kickdown function.
I have seen on other forums that this can be caused by the difference in the tread depth between the new tyre and the existing tyre (8.1mm vs 4.0mm) affecting the abs or wheel speed sensors.
I am just off to replace the other front tyre so that they have the same tread depth.
Will I need to disconnect the battery afterwards to reset the system?
I had a puncture in one of my front tyres this week. I replaced the damaged tyre with a new one. This seems to have caused some tiptronic problems. The box works fine in manual, and it will change up and down in auto, however, it does not change to 5th gear once it has been forced down by the kickdown function.
I have seen on other forums that this can be caused by the difference in the tread depth between the new tyre and the existing tyre (8.1mm vs 4.0mm) affecting the abs or wheel speed sensors.
I am just off to replace the other front tyre so that they have the same tread depth.
Will I need to disconnect the battery afterwards to reset the system?
An old tyre on one side and a new on the other caused havoc on my 5 series and the traction system......loads of lights etc.
i think having a new tyre will sort it out.
In your case, I think it comes down to the car thinking the 2 front wheels are doing different speeds (which I suppose they are).
i think having a new tyre will sort it out.
In your case, I think it comes down to the car thinking the 2 front wheels are doing different speeds (which I suppose they are).
cd1957 said:
hi I have seen this loads before, are the other tyres N rated, but not the replacement, this would be the cause, gearbox will change ok in manual, if u can go down a quite road and turn steering left to right, if it changes ok then its the tyre, causing different wheel speeds.
Chris
The N wouldn't matter, it's the different diameters, or to be more accurate rolling circumference, which is about 12mm different. Not a lot but noticeable.Chris
To Realist123,having been working on Porsches since 1981,at main dealers, we have seen tiptronics fitted with a non "N" rated tyre, when this was the only tyre in stock cause, Tiptronic gearbox changes to change exactly as the starter of the topic is getting. The last one I had was 4 weeks ago, the tyre did not have the extra load side wall, so wheel speed on that wheel was out compared to the others.
Chris
Chris
cd1957 said:
To Realist123,having been working on Porsches since 1981,at main dealers, we have seen tiptronics fitted with a non "N" rated tyre, when this was the only tyre in stock cause, Tiptronic gearbox changes to change exactly as the starter of the topic is getting. The last one I had was 4 weeks ago, the tyre did not have the extra load side wall, so wheel speed on that wheel was out compared to the others.
Chris
Hi Chris. I spent 25 years working in the tyre industry, alongside the likes of Michelin and others. Of course, if you fitted a tyre with the wrong load index, then the car might well sense a difference, Chris
The N makes no significant difference.
Most manufacturers have the equivalent of the N rating. BMW use a star or RSC, MB use MO, MOE etc. None of them mean that much other than to identify the tyre as OE and very few people pay any attention when replacing.
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