DME data on a 996 C4 4S

[thormann]

Hi, I have checked the DME data with someone´s PIWIS on my C 4S 2004 and it looks strange to me.

The odometer shows 19.400 km, but the DME shows only 18.700km with 300 operating hours. Does it mean the DME had been exchanged?

Number of ignitions range 1 is very high with about 15.000 and 1600h. Range 2 is 8. What does that say?

I can not believe 15.000 ignitions in less than 20.000km. What is the difference between range 1 and 2?

Can someone interpret this?

Thanks, Marco

[Loren]

Stage 1 ignitions are pretty normal results of hitting the rev limiter. We do not know for sure but we believe that since they are categorized as "ignitions" that for one engine revolution (in say 1 second) you would get 6 ignitions. Either way these are "safe" over revs because the rev limiter protected the engine. I would not worry about the number.

Stage 2 ignitions are over revs the rev limiter can not protect against - such as a missed downshift. In some cases Porsche may deny warranty claims if there are many stage 2 over revs - as they are viewed as signs of abuse. i have seen cars with hundreds and thousands of stage 2 over revs. i certain would worry about 8.

[thormann]

Thanks, Loren!

But any idea about the discrepany between cluster km and DME km? What does the second number at ignitions with "h" unit mean?

[Loren]

I am not sure what you mean about the DME km and the cluster km. I don't recall the DME keeping km traveled.

The number after Number of ignitions, range 1 (or 2) is the engine operating hour of the last over rev.

[thormann]

Thanks again!

When you recall the DME Datas with a PIWIS Tester, you get something like (Unfortunately I do no have a screentshot)

Ignitions range 1:

Ignitions range 2:

Operating hours:

KM:

There was more, but I do not remember! The KM shown here are about 700 less than the total KM shown in the instrument cluster. What can be the reason?

[Tool Pants]

I do not know the answer, but have seen this.

Guy with a 2002 C2 came by my office and I hooked it up to the PST2, and played around.

Saw 60,618 km in the DME. The US car had the factory OBC so I asked the owner to convert the odometer from miles to km and the OBC display showed 63,236 km.

[rb101]

Could the difference be the adjustment of 5 mph in the speedo as the "safety factor". Mine is 5 mph so for every hour driven, I actually going 5 miles less then what I should be. Does the odo reflect true mileage or this adjusted mileage by the speed factor? If so then my vehicle truely has less mileage on it.

Rick

99 996C4

87 944S

78 924

I do not know the answer, but have seen this.

Guy with a 2002 C2 came by my office and I hooked it up to the PST2, and played around.

Saw 60,618 km in the DME. The US car had the factory OBC so I asked the owner to convert the odometer from miles to km and the OBC display showed 63,236 km.

[thormann]

@Tool Pants

This is what I mean!

The % difference is almost the same at my car (about 4%). Is this in every car or something special?

[thormann]

Hi Tool Pants,

From which control unit (or in which menu) have you received the datas on the screenshot. Unfortunaltey I have not kept in mind, when we hooked up to the PIWIS. Can I get those datas also from Durametric? I want to check once more, but it is easier to find a Duramteric than PIWIS!