Warranty situation on remap?

Zeebedy

Zeebedy

Zeebedy

Soldato
Joined
28 Jan 2011
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Hey guys,

Just bought a new 208 the other day, I was considering a “chip” not just for a little more bang, but fuel economy..

I’m assuming though that this would void the warranty and services etc..

Not that bothered as the 208 is quite pokey but thought I would throw it out there..


Cheers
 
Hodders said:
I've never understood - if a simple remap can add fuel economy with no downsides, why don't the manufacturers change the stock mapping?
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Sometimes they use the same engine and configuration with different maps for different models, pay more for more power.

Other times they leave head room for reliability, this can be in mechanical terms because the engine will be at its design limit with more power, or could be to cover people being cheap skates and putting poor quality fuel in, or missing service or 2 or 3, or those owners with no mechanical sympathy whatsoever (like not letting the car idle for a minute or 2 before switching off to cool the turbos and stuff, or redlining from cold etc).

Sometimes the power is what it is for repeatability, maybe they cant garuntee the higher power rating I'm more than 80% of engines they build but they can garuntee the lower power in 100% of the builds.

Or remapping could just shorten the life of the engine, however I've not seen hard evidence to prove either way tbh.

Similar to overclocking/ undervolting pc components, why Dont they do it at factory if the benefits are there to be had?

I ran a fleet of vans once where half the fleet had a remap (mostly for fuel consumption but also increased driveability) and the other half didn't. There was no discernable difference in the reliability of either in 175k of running. That said, the engines were supplied as the 75hp variant of the 1.6hdi engine and were very sluggish borderline dangerous for pulling away at roundabouts etc, the 110hp variant used exactly the same engine, turbo, injectors etc, so the map we had put on was effectively this map and the vans became much more driveable, maybe because the engine was already designed for the higher power that's why was reliable.

Anyway back to op:s question.

Modern ECUs now leave a marker on the ECU each time it's flashed and this cannot be removed (as far as I can tell) so if you needed warranty work carrying out and they checked the checksum on the ECU the warranty would be void.

If you are talking about a tuning box, then you could remove it each time it went to stellantis or for warranty work and they would be none the wiser as it leaves no tracer mark behind.

Personally I don't like tuning boxes, they usually trick the ECU into pumping more fuel in with no regard to other parameters, unlike a proper remap.
 
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It would void the powertrain warranty if the dealer/manufacturer is able to identify it's been mapped.

As sx_turbo says, most modern ECUs have a flash counter. Each time they are flashed, the counter increments and if this can be undone/prevented, no one has yet publicised it. Further to this, there are also checksums of the map applied.

Hodders said:
I've never understood - if a simple remap can add fuel economy with no downsides, why don't the manufacturers change the stock mapping?
Click to expand...

Because a map is tailored for the lowest denominator. A bespoke map, specifically tailored to the car and engine setup are always superior to factory maps. A manufacturer could do this for every car, but it wouldn't be financially viable, and each car would also have a different power output, emissions results... it's not practical.

It can also sometimes be financial or tiering models. For example, a 981 Boxster S has ~311 HP. A 981 Cayman S has ~320 HP despite being exactly the same engine, in exactly the same chassis (minus the convertible), with exactly the same gearbox, ancillaries, etc. The only difference is in the throttle map where the Cayman can hit 100% throttle but the Boxster cannot.

In other instances, it can be done for linearity or drivability. I had an FK8 CTR that I flashed with Hondata years ago. Whilst it definitely had a huge uplift in power and torque, it had this awful surge at 3k then an extremely flat mid range; it regularly broke traction because of the huge torque increase down low. Overall, it made the drivability poor - like I was driving a diesel with the low end surge and dead mid range. I removed the map quickly and sold the Hondata on. Bigger numbers aren't always better when you drive a car everyday for everyday life purposes.
 
Hodders said:
I've never understood - if a simple remap can add fuel economy with no downsides, why don't the manufacturers change the stock mapping?
Click to expand...

Quite often they don't actually improve fuel economy, the way the computer calculates MPG is usually done by how much air the engine takes in so once you start messing with the map it'll throw off the MPG figures. SO it may APPEAR like you're getting better MPG on the dash but generally you're not actually making any savings in real life.

The OEM's will do pretty much everything in their power to give the best MPG out of the box as it's a huge selling point for people so i doubt they leave anything 'on the table' which doesn't shorten the life of components or have big compromises.
 
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Nothing will impact fuel economy as much as keeping your tyres inflated and driving more sedately.


If you get more performance, chances are you’ll use it, and use more fuel in the process.


Unless you’re specifically going for an eco map, I highly doubt you’ll see an increase in MPG.


Either way it’ll void the warranty and you’d need to tell your insurer.
 
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Seems odd that re-maps are so easily spotted ....but I thought clocking was still an issue , despite EU anti-tamper rules for manufactures
(if you can register flash re-maps, then recording miles/engine-rotations indelibly once a month should be possible .. with any future mileage based taxes it's even more important)
 
... if you are buying a used car from a dealer what's the easiest way to get it checked for any residue of a map/tuning-box ...
like, could you pay bmw some money for a pre-purchase health check
 
jpaul said:
... if you are buying a used car from a dealer what's the easiest way to get it checked for any residue of a map/tuning-box ...
like, could you pay bmw some money for a pre-purchase health check
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You won't be able to tell if a tuning box was fitted unfortunately.

A health check by BMW won't show much, that will just be a Service and check over the suspension and underside of the car, and listen out for any unusual rattles / noises. If you ask nicely they can carry out a compression / leak down test, but this can be quite labour intensive on modern engines.

A proper health check to check engine condition would be quite intrusive, on the large industrial engines I deal with at work, we remove the injectors/spark plugs and carry out a borescope and compression test, remove the rocker arms and inspect, and remove the sump, inspect for metal particles and check the condition of the big end and main bearings (some of the larger engines we can access the mains and big ends without dropping the sump). Put it back together with new seals and gaskets, change the filters then give it a run.
 
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