ALDL Interfaces

[David A. Cooley]

Hmmm...
According to the OTC tips and techniques manual states that the Field
service mode is "normal ECM functionality with the exception of the SES
light... It is used to indicate instantaneous rich-lean status...".  With
the engine off, it is used for pulling trouble codes and also tests a
variety of actuators under the hood (Cannister purge is one... you can hear
it clacking away).  but it definitely states that while engine is running it
is a "normal" road mode.


-----Original Message-----
From: Padgett 0sirius <padgett at gdi.net>
To: gmecm at efi332.eng.ohio-state.edu <gmecm at efi332.eng.ohio-state.edu>
Date: Wednesday, March 17, 1999 11:01 AM
Subject: Re: ALDL Interfaces


>At 09:14 PM 3/16/99 -0500, you wrote:
>>Actually, Field service mode is normal driving mode with the Check engine
>light flashing to indicate rich or lean...<
>
>Have had engines act really strange in that mode (paper clip from A-B is
><=500 ohms) - is really to make the light blink trouble codes & suspect the
>ECM ignores its other duties then. Should only be entered with engine off
>and ignition on.
>      A. Padgett Peterson, P.E. Cybernetic Psychophysicist
> Anti-Virus, Cryptographics, & Antique Radio Researcher
>http://www.freivald.org/~padgett/index.html
> mailto:padgett at gdi.net     PGP 5.5 Key on request
>
>