ALDL Interfaces

[Richard Wakeling]

David A. Cooley wrote:
> 
> 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.

 Except "Spark timming" which is locked to 10 Degs usually under 2000
RPM.
 
> 
> -----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
> >
> >