strange check engine light

[Jeremy Gonyou]

>Ok, I've got a problem I haven't seen here before. I had to transfer the 
>ESC
>and netres chips from a "bad" 27256 memcal to a good memcal. When I crank 
>the
>engine, the SES light comes on rather quick and the engine idle is way up
>there. Sounds like the idle air control is wide open with all the hissing.

This sounds like back up fuel mode.


>When I install the field service mode jumper between ALDL A and B (engine
>running), the light goes out and the idle drops to normal. I remove the
>jumper and it runs fine from then on until the next crank. The code I get 
>is
>code 51, which I believe is an EPROM code.

Yep.


What does putting it in field
>service mode have to do with code 51 and why does it fix it.  This is a
>strange one.  JW


I don't know what field service mode and backup fuel have to do with each 
other.  But I think if you check your soldering you'll find the problem.

Jeremy
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