ayu

Just got my car back from Sunnyvale Acura, lucky me they got one extra transmission in stock I got my car back in 2 days. Everything feels fine with the rebuild transmission in my car. While I was there, the service guy told me they had one customer with transmission problem twice (a CL-S). After the 2nd time, they decided to put a datalogger in that car to monitor the driving pattern. It turn out that the driver was driving the car very harsh, down shifting to 2nd and running 2nd gear (not in SS mode, he shift it into 2nd gear) all the time when going onto the freeway.
My question is:
1. Can dealer put on data logger without customer's acknowledgment?
2. Where can they put the datalogger?
3. Even the owner of the car constantly using 2nd gear, can Acura void the warranty?

AYU

scalbert

Very unlikely, but who knows for sure. Cheap data loggers can tap into the analog signals and record some data, but how much?? They would probably use a FIFO as complete history would be unattainable.

If there is a new device to monitor the digital signals, the history issue still holds true. How much non-volitale data can be stored, 2 hours worth?? No to mention how can it be retrevied??

They were just BS's or not knowing the truth. The PCM does hold a history, but that is an event history. Capturing the last data before a DTC is set, etc.

ayu

I was thinking the same way...I don't think they going to use a analog data logger in there. If they did and without my
acknowledgment, hay...free data logger for me! I can try to make this work on my another car.
And I think it is possible to data log by even or change the even definition. As I remember, BMW were having problem with
their M3 (older one, pre 1998) when driving under high speed and load the piston may hit and bend the valve. One of my
friend got question by BMW tech when he bend the valves in his M3. At the time he was racing on freeway and he down shift total of 6 time from 5th to 3rd and all the way to redline with hitting the rev limiter all 6 times. The BMW tech showed by friend all the even with their BMW ECM scanner at the dealership...
I think for Acura the most cost effected way is to put a different transmission ECM with different set of definition for even
(down shift at high speed, down/up shift constantly, ect). So they can keep track of what is going on with these tranny.

AYU

ABlueCL-S

....
interesting...

Hmmmm..but again..since the computer in the car is in a proprietary language by acura, and even TUNERS won't get into to it for fear of lawsuits..maybe they found or added some unused memory area..if you wanted to set a trigger to ONLY record specific events such as redline and record the gear, shifter position and duration of say rev limiter activity, they might try to yank the data and prove abuse..but...as far as I am concerned, acura put the rev limiter in there to protect the car. if they want to enhance the durability, they can either decrease redline with the rev limit or beef the trans..not being a mechanic i cant say which is better..but being a programmer/firmware/software engineer, I would say it is easily possible to record this data, and with the price of memory and electronics so cheap..it's just too easy for me to believe that they WOULD do it to cover their own asses...on the hand...if they add that capability and it costs an extra 50 cents to $1.00 increase to a component, would they really do it? hmm the possibilities..

steve

scalbert

This is already intact and mandated by the Government, in OBDII. Whenever a DTC is set a snapshot of various engine parameters is taken and stored in non-volatile memory.

This way, such as with over-revving in a missed shift (which rev limiters can do nothing about), the RPM would be captured (along with other data) showing that it was user error.

This data is available as the OBDII standards are defined and available. Scan tools and software can allow even the individual to read the DTC's and snap shot data, along with live parameters.

But in the case of the original post, they were talking about data logging, not just a snap shot. There has been some talk with the Government and manufacturers about keeping a FIFO of the last 30 seconds or so of data. The idea is to help determine the cause of accidents, etc. Not unlike flight data recorders. But of course there are privacy issues at stake which are slowing this implementation. But from what I recall, there are or will soon be some GM vehicles with this capability.

tankmonkey

do you mean a LIFO method (last in, first out)?

FIFO (first in, first out) would require a complete history (because that method uses the oldest data first) in order to make any since of the data.

scalbert

http://www.daytronic.com/products/cards-sf/10AFIFO.htm

This is the type of FIFO card we typically use in front end data acquisition systems. True, it would be a in circular format (buffer fills up and when full the oldest data is over written) so some time of Key would be needed to sort the data.

As for what they do in the PCM's, I can't honestly say how they are formatting the saved data. I stated FIFO as a quick reference to indicate muliple elements (array) and of course multiple dimensions, it isn't a single row of data.

tankmonkey

I gotcha now. thanks.

ABlueCL-S

AH....now i c said the blind man...lol..

steve