The three ECU dumps I have from my car show errors. The two newest dumps show to a few of the top 10 peak RPM values LOWER than the oldest ECU dump. After inquiring with Lotus, I received an email from an engineer stating that different diagnostic tools can cause erroneous data dumps.

 

Interesting question. I never did the hours/mileage calculation when I got my dump in October.

Could it also not be b/c of an ECU flash, or the recall to put the correct VIN in the ECU. Would either of these have wiped the memory?

 

Looked at the link and there's a discrepancy between the VIN as entered and the VIN as read. The latter has dummy letters where the production # should be.

 

The garbled vin is a common occurrence on earlier cars

 

Is that what the ECU recall was for? In his buyer's videos, Rob at DW says the 05s had a dummy number, 30000 IIRC, rather than the actual VIN.

 

I think the recall/reflashes for the 06 ECU's had to do with their not having worked through all the issues in going to drive by wire.

I had an 06 Exige. Imagine my shock when I had an ECU dump done, and it showed a peak rev of, as I recall, around 13K.

Car was under warranty at the time, and I asked the Lotus service manager about it. He said I must've over-revved somewhere along the line, and that the engine warranty likely would be void.

I pressed the issue, saying I had never missed a gear. I calculated that to get to those revs I'd have to be doing north of 90 in 1st gear. I also pointed out that the engine would've been destroyed, yet there it was, running perfect.

He reached out to Lotus USA, which in turn contacted Lotus UK, and sure enough, they said it was an ECU problem and they authorized a reflash. They sent documentation saying that the ECU readout as of that date was in error. When I sold the car, all the documentation conveyed.

 

I asked for and got an ECU dump before I bought my car. Frankly, I don't think it told me much and I doubt some of the accuracy. I think we tend to overrate this option as a good inspection tells much more.

 

+1

and its so easy to misinterpret the data.

 

glad I found this thread as I thought the info in that dump sounded too good to be true!

 

This is a very good question. I hope Phil can shed some light on this. My question is when doing a supercharger upgrade, does the reflash erase all previous data?

 

I had an 06 Exige. Imagine my shock when I had an ECU dump done, and it showed a peak rev of, as I recall, around 13K.

Car was under warranty at the time, and I asked the Lotus service manager about it. He said I must've over-revved somewhere along the line, and that the engine warranty likely would be void.

I pressed the issue, saying I had never missed a gear. I calculated that to get to those revs I'd have to be doing north of 90 in 1st gear. I also pointed out that the engine would've been destroyed, yet there it was, running perfect.

He reached out to Lotus USA, which in turn contacted Lotus UK, and sure enough, they said it was an ECU problem and they authorized a reflash. They sent documentation saying that the ECU readout as of that date was in error. When I sold the car, all the documentation conveyed.

I had this exact same issue. One readout said 8.5k rpm. The next said 13.5k rpm. Engine runs great... so...? The response I received from Lotus UK also addressed this issue with the following:

"It does look like the two printouts are from different diagnostic tools and the data for some reason has been misinterpreted or is corrupt. As you say, at 13,000+ RPM there would not be much of the engine left!"

 

IMO, ECU dumps aren't particularly useful anyway. My car, for example, has been driven on the track about 40% of its miles, so I'm sure it shows a disproportionate amount of high RPM operation.

My cams and rockers are perfect, with no signs of wear. Leakdown is great. I haven't inspected bearings, but I have no doubt they are perfect too. Frequent oil changes, no over-revs, no overheating, proper warmups, and no abuse is a lot more important than babying the engine.

 

I'd take it with a ton of salt.
However, it might still give you some idea of how the car was driven if you think the driver of the car has a particular driving habit.

 

necrobump.

I have more reason to doubt the accuracy of the data dump.

First, I find it hard to believe the explanation about different data retrieval devices causing discrepancies- unless they were not interpreting the received bytes the same way. I mean to say that I expect that different devices will read the same data from the car (any serial data errors will violate the checksum), but that the math performed on the data is a possible source of error.

1) I know that my car was previously driven fast by KirkScheidt: http://www.lotustalk.com/forums/f3/lotus-standing-mile-runs-99335/

However, the data dump shows no standing starts, a max wheel speed of 147 kph (91 mph), and the fastest 0-100 and 0-160 kph times as larger than 25.5 seconds.

2) Although the reported times spent in different RPM, throttle position and wheel speed ranges seem reasonable (albeit with no time spent above 150 km/h), the chassis reported mileage (~61000 miles) and total run time (~19.4 days) gives an average speed of 130 mph over the life of the vehicle. This is certainly not accurate.

 

I've heard of several cases where the ECU log will clear itself if it's left disconnected from the battery for too long. With how often these cars have dead batteries, it doesn't sound unlikely.