Cobalt ECM puzzle! Can u help me crack the puzzle?

[Arros]

Hey thanx 2 everyone who helped me out so much on this thread!

http://www.automotiveforums.com/vbul...d.php?t=934453

The car is running great...
however i have a question about the ECM

OK here's the deal.
The car is now running great with the new injectors and everything, but it still won't shift out of the default 2nd gear!
I checked wires going 2 the VSS and found they'd been spliced at sometime apparently...
This made me suspicious, and i checked with an ohm meter to and verified it was indeed a good splice, no problems.
Next, i checked the voltage and found i was getting between 8.5 and 10+ volts to BOTH wires coming from the ECM to the VSS
what!?!?
that confused the heck out of me... So i followed both wires all the way back 2 the ecm, found no breaks, verified with an ohm meter that there was indeed connection from VSS all way 2 ECM
Both wires were getting the exact same voltage at all times, but it varies like i mentioned...
Confused as heck i decided 2 take it for another test spin to see if i'd get any trouble codes.
Cruised around my neighborhood for like 20 (neighbors proly think i'm crazy... maybe i am a little lol i blame the car...)
fast, slow, turned it off, started again, anything i could think of just 2 get it 2 operating temp and see if i'd get some code... got NOTHIN.
I decided 2 call a friend of mine, who owned/operated a trans shop for many years, and he told me i probly shouldnt be getting ANY voltage to that speed sensor since that actually produces a low voltage signal the ECM uses to determine the vehicles speed, and the fact i'm not getting any kind of trouble codes tells him i probly have some internal problem in the ECM.
Now, another friend got me an ECM from a junk yard car that was supposed 2 be from an 06 cobalt as well (i have no way of confirming this especially since the donor is probably somewhere being processed as raw materials for... silverware or sumthing by now) but the numbers and letter codes are completely different from the original. It also has a nice dent on it lol. Merles says they can try flashing the one that was given to me at a charge of 75 bucks, however if it's physically damaged they may not be able 2 do anything. The original is not dented lol however... it's the original! it shouldn't HAVE 2 be flashed... right?
and if i buy a new (ahem, 350 dollar) one, i still have 2 get it flashed! I just have my doubts and need 2 know 4 sure if it's bad! is there any way 2 test that ECM?
Anybody got any suggestions? Or... anything!? This car driving me crazy and it's sitting there! can't drive it anywhere like this!!! lol

THANX 2 anybody willing to read this ridiculously long post and especially those willing 2 share any info!

[Arros]

Dang lots of views, no responses...
Guess everybody as puzzled as me?

[rodeo02]

This is a tough one w/out a factory service manual. Are you showing any codes with a scanner? Already having spliced connections to the VSS on such a new vehicle is odd.

Joel

[J-Ri]

don't check the integrity of a splice with an ohmmeter, check it dynamically with a voltmeter. A connection can show zero ohms and still have a volt drop across it when there is the slightest amount of current flowing through it.

That said, it is probably in the ECM... there should be a code if there's a problem with the circuit. Also, any fault in the circuit shouldn't cause the car to go into limp-mode (second and reverse only). This is one of those "swap 'n' pray" things... especially with that much (and varying) voltage on the wires... I'm 99% sure they should have a regulated 5v and the ECM reads the frequency of the pulses.