V1 Anti Theft Re-engaged, Blowing ECM fuse and ignition fuse on BCM

[KingChuck24]

Which switch, the one that connects to the D1 pin and the accessory power?

 

[Gtstorey]

Ignition switch

 

[KingChuck24]

Well I was not able to find the actual ignition switch connector but I was able to find the keyless entry connector:

 

[KingChuck24]

Did some more testing today including checking all grounds again and disconnecting then reconnecting all of the bcm plugs and still couldn't get anything. The only direction I can see from here is the passenger side brake light always being on, I tested the pin on the bcm port that it goes to and that is the only pin that is ungrounded that I could find. I checked how I wired it in and it all look good and with all the grounds being checked and working I am not sure what to do. I will go through the circuit number of that pin which is no. 19 and it is also pin a12 on BCM c3.

 

[Gtstorey]

The way I read the earlier diagram, you should have a direct connection from the b+ through ignition switch to the pin 2 on the TDM when the switch is turned. You were turning the switch when checking for voltage there?

 

[KingChuck24]

So I just checked it again to be sure and I when the key is turned I got no voltage when pin 2 was being touched and ground was being touched.

 

[snirtman]

So I just checked it again to be sure and I when the key is turned I got no voltage when pin 2 was being touched and ground was being touched.

I'm dealing with a wiring issue of my own and digging around in the forum I came across this post that has excellent layouts and wiring descriptions for every wire and connector in the car. Might possibly be useful to you too. I think it starts at post #158 if the link doesn't automatically start there, and continues for about 12 posts after that.

 

[KingChuck24]

Cool thanks, I will take a look.

 

[Gtstorey]

You need to find out why you aren’t getting voltage on that pin 2. Either power isn’t getting to your ignition switch or the switch is bad. Unplug the connector on the ignition switch and see if you are getting voltage on the red/white wire.

 

[KingChuck24]

So from pin 1 on the alarm module connector which is the red and white wire I am getting battery voltage. On pin 2 I am getting no volts and that should go down to c8 on BCM plug c4 and that is also not getting voltage. Does this mean that the anti-theft module is bad?

 

[Gtstorey]

So from pin 1 on the alarm module connector which is the red and white wire I am getting battery voltage. On pin 2 I am getting no volts and that should go down to c8 on BCM plug c4 and that is also not getting voltage. Does this mean that the anti-theft module is bad?

No. This means that the switch is not supplying power to C8. The diagram indicates voltage flowing from B+ (basically Battery Positive) through the ignition switch in the run position (and probably accessory position) and out pin 4. This voltage then flows to both BCM pin C4-c8 and TDM pin 2. The junction point/split is in different location for the manual transmission(M86) and the auto trans (MN5).

I'm thinking that you may not be getting voltage (B+) to the ignition switch which may affect more than just the TDM/BCM but would need to see more diagrams to know for sure. But just the TDM/BCM voltage lost would probably cause a no start.

 

[KingChuck24]

I guess I sort of follow that. So then if it is not getting voltage do you know where that pin 2 traces back to? I am a little confused about where it should be getting voltage from, unless it is supposed to get it from c8.

 

[Gtstorey]

It gets power from the ignition switch. Power splits at junction S206 for the auto trans. Below is the auto trans path. Manual just has the junction point at C8 pin.

 

[KingChuck24]

Ok I think I follow that. So basically somewhere in that circuit there is a disconnect meaning that there is no accessory voltage signal. I dont see any other connections besides the c8 pin on the BCM though. Is it possible I burnt out the BCM?

 

[Gtstorey]

Why don't you want to check the ignition switch? It supplies power to both the BCM and the TDM.

 

[Gtstorey]

Why don't you want to check the ignition switch? It supplies power to both the BCM and the TDM.

Actually I'll change that.

It calls it a signal, so it uses +12v to the BCM and ECM to tell them they are "needed" or to "wake up", they don't actually power them. Doesn't change that you should have +12v at those locations if the switch is doing it's job.

The BCM is not putting out a +12v signal, it's receiving it.

 

[KingChuck24]

So then is pin 2 then receiving 12 volts direct from the battery? In which case there would be a powering issue and likely one of the wires is the issue.

 

[Gtstorey]

Not exactly "directly from the battery" but eventually from the battery after it passes through the ignition switch.

 

[KingChuck24]

Ok so I went and unplugged some things and replugged some things in and now pin 2 has battery voltage. I am measuring from pin 2 to the battery positive, but when I measure from pin 2 to ground I do not get any volts even though it is grounded. Is that an issue? Where is all that electricity going?

 

[Gtstorey]

It's hard to tell exactly what you are saying but sounds like you have a short to ground on the wire at pin 2.

"Where is all that electricity going?" This isn't really how things work.

If you are going to refuse to do any checks on the ignition switch, I'm going to have to let someone else help you. Random checks will only get you so far.