From: kenny@osf.org (Kenneth Crudup)
Subject: Re: 90 Escort GT engine race at idle ?
Organization: Open Software Foundation
Distribution: usa
Date: Tue, 18 Aug 1992 15:30:09 GMT

In article <1992Aug17.232156.20962@tandem.com>
norcott_bill@tandem.com  (Bill Norcott) writes:
>As stupid as the EEC-IV is, it will still spill out trouble codes 
>with this kind of problem, so instead of 11 (normal) it will emit
>13 (idle speed) or some such.

No, it won't. Since the EEC-IV engine "computer" has no real control over
idle, Ford's engineers "forgot" to add in a trouble code for it. (OK, OK,
"idle" is a hard phenomenon to check, but you get the idea). Seriously,
my experience w/the EEC-IV is that by the time the car reports a trouble
code, the subset is so damned simple, and the tolerance is so high, that
any half-competent mechanic (even me!) knows what part is bad anyway.

In article <Bt5xzH.110@news.cso.uiuc.edu>
jsc52962@uxa.cso.uiuc.edu (Jeffrey S. Curtis) writes:
>Is there any way for normal humans to read the codes off the EEC-IV,
>or do you *have* to pay the $50-$60 for your friendly Ford dealer to do it?

No you don't. I do it for my Merkur all the time, and you can too.

Special equipment required:

1 - (one) Chilton's Electronic Engine Manual (or something like that; I forget
	the exact name), for exact procedures for your vehicle, and for
	deviations from the code. Price: $20. Make sure you get the domestic
	model, and the right year set. I bought mine at an ADAP (ie, just a
	basic aftermarket parts store).

1 - (one) Analog VOM. Rat Shack's got 'em for about $10 nowadays. DON'T get
	a digital one, you'll need the meter to see the swing.

1 - (one) Pair of alligator clips. 10 come from Rat Shack for about $3. Get
	the small kind so they fit into the holes in the connectors. If you
	get fancy like I did, you can crimp male spade lugs on a 1/2ft or so
	of wire, so they fit into the connectors normally.


Essentially, the procedure is to find your ST (self test) wire, and ground
that. There's a prism-shaped connector, usually on the passenger side of the
engine compartment, and in the same harness, a self-hanging connector. (Now
you see where the Chilton's book comes in handy). The self-hanging connector
is the ST lead. In the prism connector is a convienient ground, but your
battery's probably right there. You then find the output lead on the prism
shaped connector (...RTFM), and attatch the negative lead of your VOM
(on a 10-15v scale) to that, and the positive lead to the + of the car
battery (there may be a lead for that, too, in the prism-shaped connector,
but I just find the battery convienient.)

There are two modes- KOEO (Key on Engine off) and KOER (Key on Engine running).
KOEO is for getting stored trouble codes out. KOER is a dynamic test, that
may also require actions taken after the test is started (once again, the 
Chilton's is invaluable to Xref your particular car. My 'Ti requires the 
brake pedal to be depressed after the "separator" code (beats the hell outta
me why, too), and then the throttle to be "goosed" (WOT for a quick second)).

KOEO is the easiest. Ground your ST connector, turn your car on, and watch the
needle. The codes will come out of the computer serially, with a space between
the digits, each code repeated twice, then the next if any, and then it starts
all over again. (Once again, RTFM, 'cuz I think there's something in front of
this, but I don't remember.) Code 1-1 (Allegedly all signals OK) will come out
like this:

	Sweep (2 sec) Sweep (4 sec) Sweep (2s) Sweep ....

and say, 3 - 4 like this:

	sweep (.5 sec) sweep (.5s) sweep (2s) sweep (.5s) sweep (.5s) sweep
	(.5s) sweep (4s) (then all that again, then the next code, if any)

Since, for example, 6-7 means one thing on your car, and something else on
another, get the manual. It's lifted right out of the Ford Engine Diag book,
and is quite simple, and easy-to-follow, as your typical Ford mechanic has
to be able to understand it.

See, all this hoopla about electronic cars and special equipment is BS to
me, because no automaker (today) is gonna build a car that a qualified
mechanic can't fix. Word gets out about that, and sales will fall. I've
yet to see an electrical/electronic component that I can't diag or work 
around, given the right information.

	good luck,
	-Kenny
-- 
Kenneth R. Crudup, Contractor, OSF DCE QA
OSF, 11 Cambridge Center, Cambridge, MA 02142	+1 617 621 7306
kenny@osf.osf.org			OSF has nothing to do with this post.
Not one of the "PC" weenies.