stuck between 1281 and 1216 check engine codes

[static]

Hi

researched this on few forums to no avail

The story is, if i reset (unplug/replug) the ECU and follow the proper resetting procedure (5 min idle , then drive for a bit like human being), then if the car idles for awhile, i eventually get 1281 which seems to be the power supply for ECU memory code (guess voltage is going low until it's no longer enough to sustain the stuff learned by DME).
So after i get this code and shut the car off and restart, i get 1216 code , which is TPS code.
My theory is that once DME "looses its memory" and 1281 is thrown, it forgets the TPS characteristics and thinks something is wrong with TPS.

I have yet to test voltage range during idle, but i am just curious if anyone experienced similar troubles on swapped cars

Thanks
Alex

[matt]

Check your grounds and power to the ECU. I had a similar issue, it was both power and ground related. (IE a short)

[static]

Check your grounds and power to the ECU. I had a similar issue, it was both power and ground related. (IE a short)

Thanks Matt
remind me where the grounding points are in the eng compartment, i think i saw one on the frame under the hood, but i don't recall seeing any more of them
There is also some small ground cable that gets bolted to one of the coils - what is this one for?
Where exactly did you have a short?

[matt]

I am too embarrassed to say where my short was...

The grounds are off the DME connector just inside the engine compartment... I think the DME power wire is there too. Check the DME connector diagram in the bentley and see what pins are power and ground and check them with the DME disconnected.

[Mike B.]

I am too embarrassed to say where my short was...

You can't get off that easy... Remember, this is for the good of the community. :D

[static]

ok, just checked the running voltage on battery terminals and it's 19.something volts!!! i read it may be symptom of alt (regulator?) going
normally it should be like 14.5-.9 or so right?

anyone knows if it's the culprit?

[matt]

You know those two brackets that support the intake manifold?

One of them, if it comes loose just right, swings in the perfect arc (get it?) to short against the main power line going to the starter.

Mine came loose and my car started cutting out intermittently (mostly in turn 5 at RA, not a good place to lose power). Threw a code for the TPS and cam sensor, depending on how it felt at the time, I guess.

[static]

don't be too embarrassed, when i was working under the i-mani, the arc of my wrench was perfect to cause lots of sparks (touched the starter contacts)

could this have fried anything (battery seems to be fine after i trickle-charged it)

[matt]

Anything's possible...

[static]

Holy ^$%^%#!!

changed alt (whole assembly with regulator) yesterday for a used but quite new looking unit and still same result 19.something volts at idle!!!

wtf? what could possibly be the culprit?

[static]

ok update

me and my friend think that it's the reference alt wire is somehow disconnected.
Where exactly is that alt wire (that's attached to smaller 10mm post on alt) terminates on the other end? Do i have to pull the manifold again to check it?

[matt]

That wire connects to pin 1 on the C101, IIRC.

[static]

yea thanks, i've tested and continuity is fine, and the alt reference wire gets all of the 19.something volts, somehow it just doesn't regulate.
Is there something that could keep frying the regulators???

[static]

fuck me!

doesn't it suck when multimeter shows you bullshit numbers? numbers you rely on

what do i do to not get these codes now....

[Mike B.]

Could there be a bad capacitor in the DME? This might explain the power supply for ECU code...

Could you try another DME to see if you get the same codes?