06 9-3 aero convertable No power to ecm or tcs

[Linconwaysaleservice]

We have been working on diag for this thing for awhile now. Tech 2 can get signal from either ecm or tcs and wont let us in to do anything else. New battery, New fuse panel by the battery, replaced the ecm twice, new relays which have power to them. The dealer said its the Ecm even though we replaced it. #6 fuse keeps blowing for some reason. Its on the back burner right now but we would like any input possible. thank you

[Digger]

Engine would be helpful to know, also when it blows the fuse.

In the mean time: If it's an auto unplug the transmission range switch, the transmission control module and the starter relay. Give the wire harness the most careful end to end visual inspection possible, plug things back in the way you took them out and keep trying the key until you blow the fuse.

[Linconwaysaleservice]

Engine would be helpful to know, also when it blows the fuse.

In the mean time: If it's an auto unplug the transmission range switch, the transmission control module and the starter relay. Give the wire harness the most careful end to end visual inspection possible, plug things back in the way you took them out and keep trying the key until you blow the fuse.

Its a 2.8 sport and the fuse blows as soon as you turn the key

[Digger]

Its a 2.8 sport and the fuse blows as soon as you turn the key

Is this with module, switch and whatnot unplugged?

[Linconwaysaleservice]

This is with everything plugged in at the moment

[Digger]

You have a dead short somewhere and isolating circuits by unplugging all the things that are directly feed by that fuse and putting them back in the circuit one at a time will save frustration and few fuses. No silver bullet for this type of problem, sometimes you get real lucky and find it the first place you look, usually not.

The mostly cause for a dead short is harness damage and this can usually be found with a good hands on close eyeball inspection for chafing at clamps, breakage at flex points and any place a small rodent could chew. With the dealer telling you that the problem is the ECM, wouldn't hurt to unplug and leave it unplugged for as long as you can. The least likely though not impossible cause could be plug connect under the carpet where a Coke was spilled 6 years ago rotting to the point that it has become a part of this circuit and just in case it wouldn't hurt to protect this for as long as you can.

The tranny switch can break on any car, the Chevy V6 has a real nice place atop the starter motor for a small squirrel to curl up on a cool autumn day and they do like to chew. If you have a lot of brown squirrels in the area, look there first.

[Linconwaysaleservice]

ok well we fixed the fuse issue, there was a bent pin under the fuse box, after putting it back in the fuse is fine now. I checked all the wires to the ecm and there is power going to it and appears to be coming back out as well yet the tech 2 still reads no voltage. I can read trouble codes though which if it didnt have power I would think I couldnt.

[Digger]

ok well we fixed the fuse issue, there was a bent pin under the fuse box, after putting it back in the fuse is fine now. I checked all the wires to the ecm and there is power going to it and appears to be coming back out as well yet the tech 2 still reads no voltage. I can read trouble codes though which if it didnt have power I would think I couldnt.

This is progress and it's a tough one to answer here. I've had a couple of Trionic 8's open, actually fixed one and taken some wild trips down the rabbit hole learning what I could and couldn't do with a clone Tech 2.

The ECM has power and the ECM isn't telling the Tech 2 everything it should. Is this the problem you had before the fuse panel change? To save some time, if it is ignore it for now and clear all codes before you run the BUS test.

[Linconwaysaleservice]

I cleared all codes and ran the bus test on ECM, TCM, and TCS and no response from any of them up to 20 errors before I moved on.

[Digger]

I cleared all codes and ran the bus test on ECM, TCM, and TCS and no response from any of them up to 20 errors before I moved on.

This is the kind of thing that can be caused by something spilled on the carpet years ago, or by something entirely different. Not your good old fashion run of the mill auto electric problem, this is a computer network problem and doing anything by text will take forever. I Googled Lincolnway in PA and found a phone number, if this is you I'll give you a call tomorrow if you're open. Phone is better than writing, and no guarantee we can do any better by phone, but it will save a lot of time finding that out.