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V1 Electrical start issue

G
Was the NA donor an automatic car?

You definitely need to follow up on the no resistance on pin 6-14. This indicates a break in the high speed data wires.

You also may have an issue on pin 6 of the ignition switch. That is 5v supply from the bcm to the switch so a voltage drop may indicate a bad connection or you are checking to a bad ground. I don’t think the low voltage reading itself is likely to cause a no start though.
 
D
Was the NA donor an automatic car?

You definitely need to follow up on the no resistance on pin 6-14. This indicates a break in the high speed data wires.

You also may have an issue on pin 6 of the ignition switch. That is 5v supply from the bcm to the switch so a voltage drop may indicate a bad connection or you are checking to a bad ground. I don’t think the low voltage reading itself is likely to cause a no start though.

thank you. This is what I am seeing
 

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G
Hard to troubleshoot this when every time you read something you get different values. Somewhere around 60ohms is correct for the high speed data wires. Do you know why you have a 60 now and something different before?
 
D
Hard to troubleshoot this when every time you read something you get different values. Somewhere around 60ohms is correct for the high speed data wires. Do you know why you have a 60 now and something different before?

I think I have 60 now because I am using a new meter…and I am learning more how to use it.

another troubleshooting item I performed:
Touched screwdriver to starter pos to ground to see if it would crank and no crank but spark.
 
M
The 2.2 was a manual. The starter worked when we made the compression check on the engine. It's a new starter.

You only need to bridge the solenoid of the starter. I L that will push the gear forward and spin the engine. If that doesn't work, i would check the battery connection 12v and ground. You can easily have 12v with a bad connection but don't get any amperage.

It could be that the voltage collapses once to much load is on a bad connection.
 
M
If you made a short between battery positiv and ground with a screwdriver there should be not mucheft over from the screwdriver. Battery short cut amps is 10x nominal amps. So roughly 1000amps
 
G
Starter positive to ground should spark and if you aren’t careful you’ll burn yourself or melt something.
Starter positive to the solenoid signal wire (purple?) should check the starter function.
But you need to get more organized in your troubleshooting. You are going to have trouble if you jump around and just try random things. Start at one end and work through the chain.
But you are probably working on the wrong side. Work the data wire problem until you can get a code reader to connect. If you have just a basic code reader that just reads the ECM, you are probably not getting power to it correctly to make it talk to the code reader.
 
A
The 2.2 was a manual. The starter worked when we made the compression check on the engine. It's a new starter.

You only need to bridge the solenoid of the starter. I L that will push the gear forward and spin the engine. If that doesn't work, i would check the battery connection 12v and ground. You can easily have 12v with a bad connection but don't get any amperage.

It could be that the voltage collapses once to much load is on a bad connection.
This unit is NOW Auto?
#1What engine/ trans harness did you use?
You may have a mismatch somewhere as a manual installation gets it's neutral safety start signal from the clutch switch in the dash harness and the automatic is in the main harness plugged into the shifter in the console. That one(in the main harness by the shifter) is two wires with a plug about the size of a pencil that plugs into the shifter.
#2 I haven't worked on a functioning auto Cobalt but it may also have a system that will not engage the starter without depressing the brake pedal? (???I'm an old guy and I've worked on/driven a lot of stuff. Plus old junk from Italy and recently rentals in OZ. Everybody has their favorite safety quirks!)
 
M
He used a new F23 gearbox from DF. The same I had.

That issue with the pedal box, is something I told him, but not sure what donor year he has. Even if that would be a mismatch the engine should stay on.

I still believe he has somewhere a weak connection in the power supply.
 
D
He used a new F23 gearbox from DF. The same I had.

That issue with the pedal box, is something I told him, but not sure what donor year he has. Even if that would be a mismatch the engine should stay on.

I still believe he has somewhere a weak connection in the power supply.

the pedal box (and all other components) is from a 2009 SS, manual
The harness is from 2009 NA
 
D
Starter positive to ground should spark and if you aren’t careful you’ll burn yourself or melt something.
Starter positive to the solenoid signal wire (purple?) should check the starter function.
But you need to get more organized in your troubleshooting. You are going to have trouble if you jump around and just try random things. Start at one end and work through the chain.
But you are probably working on the wrong side. Work the data wire problem until you can get a code reader to connect. If you have just a basic code reader that just reads the ECM, you are probably not getting power to it correctly to make it talk to the code reader.

I am using a BlueDriver

can you advise how to work the data wire?
 
G
Since the resistance checks out it’s doubtful there is a break in the wiring. It sounds like at least some of the modules are not waking up.
What modules will BlueDriver read?
 
D
Since the resistance checks out it’s doubtful there is a break in the wiring. It sounds like at least some of the modules are not waking up.
What modules will BlueDriver read?
Apologies, I am not sure which specific modules you are referring to.

 
Ross
That bluedriver link says:
"All vehicles with an OBD2 port are required to output basic information when the Check Engine Light comes on. However, a lot of important information (such as ABS, Airbag, Climate Control, etc.) is left behind by the other scan tools. Only BlueDriver gives you the complete set of diagnostics on a wide range of manufacturers. "

So it claims to read other modules.
Our goblins have:
- BCM (Body Control Module)
- Electronic Power Steering
if you have an automatic transmission, you also have:
- ECM (Engine Control Module)
- TCM (Transmission Control Module)
otherwise, for a standard transmission, you have:
- PCM (Powertrain control module). Often called the ECM too.
 
D
Data is definitely flowing. The problem is likely the above. I had to replace those bits on my car and it wouldn't start until I had swapped the PCB from the old TDM into the new TDM. I'm sure there's a procedure that can be done, but, something definitely needs to be done there.
Data is definitely flowing. The problem is likely the above. I had to replace those bits on my car and it wouldn't start until I had swapped the PCB from the old TDM into the new TDM. I'm sure there's a procedure that can be done, but, something definitely needs to be done there.

as in replace the BCM?
I have the BCM from the SS. Same year. Any harm in trying this? A replacement BCM may only be $50-100 so willing to try for diagnostic purposes at this point
 
Ark :D
No no, don't replace the BCM. I was just saying, when I replaced my TDM, I had to swap the circuit board from the existing one into it, to make it start.
 
M
Just wondering, if there would be a problem with the data lines, why would be the modules which are already up, shut down?

Keep in mind, all items were running fine. Of course if could be that a cable is broken during transport, but how likely is that?
 
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