[Diy_efi] Project/temperature ranges

[Bill Lewis]

gassr wrote:
> I agree.
> Why would GM find it necessary to use the 'automotive' range in their 
> ECM/PCMs? Asking about using 'automotive' range in automotive 
> applications may sound silly, but it appears to be a question of using 
> components with suspect (at least min.) parameters or going the
> distance on both ends, as even the 85?C range could be considered
> questionable for underhood temps.
> 
> Gary

FWIW,

Freescale describes parts as belonging to a particular application/
qualification tier.

http://www.freescale.com/webapp/sps/site/aqtlink.jsp

See pages 8-9 in:

http://www.freescale.com/files/abstract/misc/CPA_QA_HANDBOOK.pdf

They offer three temperature ranges considered Automotive tier,
all with -40C low end, and different high ends.

?40?C to 85?C
?40?C to 105?C
?40?C to 125?C

These app notes are also useful:

http://www.freescale.com/files/microcontrollers/doc/app_note/AN2201.pdf?fsrch=1

http://www.intel.com/design/auto/mcs96/applnots/21031302.PDF

Bill

> 
> ----- Original Message ----- From: "Bill Lewis" <bill at wrljet.com>
> To: <diy_efi at diy-efi.org>
> Sent: Tuesday, February 27, 2007 8:50 AM
> Subject: Re: [Diy_efi] Project/temperature ranges
>>
>> It's really the low side that you might worry about in an
>> automotive application, since 0?C isn't very cold at all.
>>
>> Bill
>>
>> Joe Vitek wrote:
>>>
>>> Commercial range is 0? to +70?C. Industrial is -40? to +85?C. 
>>> Automotive range is really tough at -40?C to +125?C.
>>>
>>>> How does the temp range for 'commercial' differ from 'automotive'?
>>>> I'm led to believe 'automotive' is designed to function within a wider
>>>> range of temp variation, with both a lower -?C and higher +?C. If so,
>>>> why deviate from automotive application norms?