Fiat declining warranty claims

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Fiat declining warranty claims

When Fiat first made us aware of the over-rev counter we checked a variety of cars on PDI out of curiousity, and they all read 0 over-revs, 0 msecs. ;)

It's possible to accidently hit the limiter when carrying out a phonic wheel learn, but it would only be a fraction of a second and the speed reached would be the fuel cut-off point (limiter), and not beyond it. Unless the Dealer has done 85 phonic wheel learns on PDI, it's not going to go out the door with 255 over-revs.

So what is an over rev? Hitting the limiter, or changing down to early into too lower a gear :confused:
 
Both. Counter starts clocking-up when at the limiter. Anything at or above it is judged as an over-rev.

The number of over-rev events, the engine speed reached, and the duration of the time spent at or beyond the limit is what the warranty claim is based on.
 
Both. Counter starts clocking-up when at the limiter. Anything at or above it is judged as an over-rev.

The number of over-rev events, the engine speed reached, and the duration of the time spent at or beyond the limit is what the warranty claim is based on.


Which means...

Some are treating their new-ish domestic motors like F1 cars.
Given the way reps drive or people with hire cars - it may be that young Johnny buys his new motor on finance (and let's face it, years ago, new cars were way out of reach of younger drivers but these days garages are handing them out like sweets, as long as your finances will cover the repayments (they don't care that your finances cannot cover anything else)), drives it brains out to show off to all his mates then starts crying to the dealer when it starts coughing & misbehaving. The car is hooked up to the computer which shows a nightly lack of respect for the almost new motor.

or

The onboard software is up the chute and a programmer has told it to multiply rather than add?
 
The onboard software is up the chute and a programmer has told it to multiply rather than add?

Not likely. The clue is in the post before yours. I wonder what the maximum event length recorded is. We humans will think the event is:

IF Engine speed >= limit
__Log(Engine speed,time at engine speed,...)

Then would a change in engine speed. Given this is likely to be an RTOS its probably a state change, so whilst in the state "overrev" increment the time:


IF (CurrentEngineSpeed>=Limit)
___InStateOverRev=true
Else
___InStateOverRev=false


IF (InStateOverRev)
__IF (NOT Exists(CurrentEvent))
_____CreateNewCurrentEvent;
__IF (CurrentEngineSpeed>CurrentEvent.EngineSpeed)
_____CurrentEvent.EngineSpeed=CurrentEngineSpeed
__CurrentEvent.TimeSlices++
EndIF

Where a time slice is the time it takes the RTOS to loop back around to this function. Or its based on a timer.

Now some have correctly pointed out that 2^8 is 256 and therefore an 8 bit register can store 0 to 255. However, that is ONE limit, what about the limit on the amount of time you can be at that limit? This again is going to have an overflow. When it reaches the limit of that overflow what happens? Does it stop recording? Doubtful. More likely it will create a successor event and start counting again. Lets pretend the limit is 10 seconds. At 10 seconds, it would create a second event.

So we change the event:

IF (CurrentEngineSpeed>=Limit)
___InStateOverRev=true
Else
___InStateOverRev=false

IF (InStateOverRev)
__IF (NOT Exists(CurrentEvent))
_____CreateNewCurrentEvent;
__ELSE
_____IF CurrentEvent.TimeSlices==10
_______CreateNewCurrentEvent;
__EndIF
__IF (CurrentEngineSpeed>CurrentEvent.EngineSpeed)
_____CurrentEvent.EngineSpeed=CurrentEngineSpeed
__CurrentEvent.TimeSlices++
EndIF

Well, maybe, this is speculation. But what if it isn't the max speed reached? What if each change in engine speed over the limit generates a new event? In that case as you over-rev changing speed you are going to generate an entire series of events.

We don't know how the software will react. To me, that is the first question.

The second scenario is, if we assume that 255 over-rev events cannot be generated by time or varying engine speed when at or over the limit threshold there are other factors to consider.

1. Does the individual drive like a pillock?
2. Is the information coming into the ECU correct?

What I mean by (2) is the aforementioned faulty rev counter. Or other sensory information that is just downright incorrect. What other conditions could generate an "overrev" signal/event?

This is the old calibration question. Is it like a series of Gatsos as you go down the road picking up multiple speeding fines with one (in your head) single speeding offence? Have the Gatsos been properly calibrated? Would it be possible for the input data to be scewed by some other fault, and in which case normal driving would trigger an event.
 
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Not likely. The clue is in the post before yours. I wonder what the maximum event length recorded is. We humans will think the event is:
...

I'm just your everyday Johnny, know nowt about how the modern car logs events (as you will gatjher from my post).

Although I do see rather a lot of very new cars being driven around by very young people - and they do seem to be treating them like F1 cars.
Today I saw 4 black guys in an 09 plate golf & from a standing start I'll wager he hit the rev limiter on every gearchange & probably halfway through his pads judging by the way he chucked out the anchor to stop at the lights.

What would be interesting, though, is for additional information to be released - it would be good to get the techy stuff for anyone who knows about it but it would also be interesting to get an idea about the drivers.
young lads showing off to their mates?
middle-aged blokes going through a midlife crisis (showing off to anyone who'll watch)?

Heck, the old boy next door to me used to reverse out of his drive by putting the car into gear, flooring the pedal & slipping the clutch - and I reverse out by dropping the handbrake & letting gravity do the rest!
 
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