While reading about another member's experience with installing his Xcal II as well as his AF1, he noted that the Xcal's instructions mention only 'flashing' the PCM when the ambient temperature is greater than 32 degrees Fahrenheit (0 degrees Celsius).

It drew a question or two in my mind....

Is this because of the electronic circuitry, potentially, not playing well in the cold or is it simply because you may or may not be able to read the liquid crystal display (LCD) on the unit telling you when to turn the key and when to shut off (among other items)?

Any thoughts? Any adverse experiences when flashing in the cold (flashing your PCM you pervs! ). Is this just one of those things that the attorneys insisted that SCT put into the directions to avoid potential legal problems (like someone flashing and being a bonehead)? Maybe it's just safety language to keep you from screwing up? Maybe the PCM doesn't do as well in the cold ambient temps?

I'm rambling...

Anyone have any ideas?

 

Well, Edge finally has an update for my truck, and I loaded it in today and the high temp was like 20 today here in Cleveland, and it worked just fine, but the unit was in the house all nice and warm until I loaded it. Hope that helps.

 

I just loaded new tunes about 2 weeks ago with my Xcal2 it was in the teen's I drove my truck let it warm up then let it sit with it running for 10-15 min and didn't have an issue. I can always rely on the Xcal2 to work.

 

Computer circuits have a high and low temp range where they won't work correctly, so the danger is a bad load, hence why the manufacturer recommends not to do it below freezing unless you take the steps to warm up the ECU on the vehicle (buy bringing the engine temp up to normal) and keeping the Flash device in the house till you are ready to do it.

Not to say it wouldn't work if you didn't do it, but with electronics and seeing how your engine's well being is at stake (if you got a bad load), I would take the precaution to do the warm up no matter what flasher I was using.

 

Thanks Fire -- that's kind of what I was looking for and exactly what I suspected.

I appreciate your input!

RP

 

Hi.

Actually, that's a generalization. The components used in the PCM ( and other quality automotive electronics - it's considered a harsh environment) are virtually Mil-Spec in that their operating range can extend safely down to -55 degrees C to +125 degrees C. 'Storage' range is even wider - down to -65 C.

The problem is not the electronics per-se - witness that your truck starts & runs just fine in very cold weather, so the PCM gives not a rat's patootie about the ambient temperature during normal operation.

The issue is the flashing process and the effect that low voltage & low temperature have on it's reliability. Writing to a flash memory device is the issue (unlike writing to RAM, which is also referred to as the KAM in a PCM - keep-alive-memory... this is also fine, again that's where PCM writes fuel trim values and other stuff to RAM during operation - the 'adaptive learning' stuff). Reading from a flash device is not a problem - again as it pertains to normal operation.

Peruse some data sheets for flash memory devices and you may find temperature restrictions have been placed on the component during the write phase, to ensure (a.k.a CYA), a reliable write - it will likely still work outside those ranges, but you are into uncharted territory (exceeding the guranteed rating) at that point. Write/erase functions always require a higher voltage (and more current) than read operations. Writes also always require more time than Reads, and the setup/timing requirements are more complex.

Vehicle battery voltage can be/is lower in cold temps. And the X2's display can get lazy, as noted. iIdon't know the operating specs or the component specs for the Xcal2's innards, though. Add it all up, and add the CYA factor as RP alluded to, and yup, it's no wonder the manufacturer says to do it when it's above freezing ( with a fully charged batt & no loads) to be safe. Oh, and no fuse pulls required on 04+ trucks, unless you have efans or a monster A/V system.

EDIT: Ahhh ... just re-read this - sorry for the wind-bag reply - just an old electronics nut who's inhaled far too many solder fumes .

Cheers
Bubba

 

Geesh - you really are a 'wind bag'. LMAO!

Seriously bud, thanks for that input. As a 'technical kind of guy', I don't mind reading stuff like that. Hell, have you seen some of my 3 and 4 post replies up in General Care and Detailing?

Wind bag -- pfft. Kind of calling the kettle black, huh? LOL!

Thanks again... -RP-

 

Hi RP.

Oh, yeah... I've seen 'em. Real page-turners, those posts.

You and Mike Troyer routinely crank out some of the best (and lengthiest) novels I've ever seen. You & he have given me and countless others invaluable advice ( free, too!). And, I get to beat up on all my friends who don't know a clay bar from Zest! Thanks!

Gotta go - 30 centimeters on the way... time to custom tune the snow blower ;-))

Cheers
Bubba

 

I truely love this site. As you said tons of free info. I just wish I had deep pockets to try everything I read! so its just and for me!

 

Hi.

Roger that !

Cheers
Bubba - (savin' empties ta pay fer LiveWire!)

 

Then stop posting and start drinkin..... And how many fine beverages do you need to pound down for your new toy?