V1 No Start Issue - B+ Terminal/Fuse Box

[Robinjo]

When I connect the B+ stud with wire to the fuse box the engine will fire and run. I can do this over and over for a while. After about 20-30 minutes, however, when I go to crank the engine nothing will happen. No lights, no starter clicking, nothing. It act like it's a dead batter, almost. If I remove the B+ post and power wire from the fuse box, reinstall them and try the engine it fires right up. Any ideas here?

I do need to pull the fuse box to allow me to get to the clutch line clip on the transmission, so I'll inspect the fuse box when out. I'll also recheck my new ground stud under the fuse box, just to make sure I got all the powder coating off the spot.

 

[jirwin]

Curious, does the same happen if you remove and readd the negative terminal on the battery?

 

[Gtstorey]

It's likely one or more loose individual wire connections on the back of the fuse box. I went through something similar of no start/no crank unless I removed one the CMHSL relay and reinstalled. This worked 20+ times until it finally didn't. It's likely not the B+ post removal/reattach but moving the fusebox a slight amount causing a loose connection to retouch. I eventually had to pull each individual wire loose on the fuse box connectors and a pry the contact point out to tighten the connection. These connectors are not really designed for multiple unplugging/plugging.

The only other thing it might be is the B+ removal is resetting the ECM. The next time it happens, remove the positive at the battery instead and see if that fixes it or try wiggling the the fusebox.

 

[Robinjo]

Curious, does the same happen if you remove and re-add the negative terminal on the battery?

I've not tried this yet. I'll give it a look.

It's likely one or more loose individual wire connections on the back of the fuse box. I went through something similar of no start/no crank unless I removed one the CMHSL relay and reinstalled. This worked 20+ times until it finally didn't. It's likely not the B+ post removal/reattach but moving the fusebox a slight amount causing a loose connection to retouch. I eventually had to pull each individual wire loose on the fuse box connectors and a pry the contact point out to tighten the connection. These connectors are not really designed for multiple unplugging/plugging.

The only other thing it might be is the B+ removal is resetting the ECM. The next time it happens, remove the positive at the battery instead and see if that fixes it or try wiggling the the fusebox.

One thing I can note is the wires on the large connector furthest rear in the fuse box are really, really tight where they wrap around the box. I have been very careful not to disrupt the box, just in case this was happening. I've tried wiggling the whole fuse box to see if the condition resets, it doesn't do anything. The only thing so far that resets it is removing the B+ terminal and re-installing it. I'll try the positive and negative terminals at the battery next.

 

[Ark :D]

I did not have this specific problem, but I did have an issue where contact was poor on the connector blocks inside the fuse box, resulting in 20+ pages of electrical troubleshooting in my build log.

Next time you have the fuse box apart, a visual inspection of the metal connectors on those blocks might be helpful.

 

[Robinjo]

I did not have this specific problem, but I did have an issue where contact was poor on the connector blocks inside the fuse box, resulting in 20+ pages of electrical troubleshooting in my build log.

Next time you have the fuse box apart, a visual inspection of the metal connectors on those blocks might be helpful.

I'm going to inspect the fuse box, the best I can when it's apart soon. I also think I'm going to extend the wires on the connector block that are tight. I don't like how they are sitting.

 

[Robinjo]

One thing I just remembered, I am getting a Cam Positioning Sensor Fault code (along with all the Evap & ABS codes nonsense). Could this have anything to do with it?

 

[Gtstorey]

Don't think that would cause a no crank condition.

 

[Robinjo]

Well shucks, I was hoping it was an easy fix. A Loogle search says it could lead to that, so I was hopeful.

 

[Robinjo]

Took the positive cable off the battery, placed the cable right back on and tried the car. Everything comes on and it'll start.

 

[Gtstorey]

I'm not sure I have much to offer if it's a reset of computers that makes it crank. Probably could be diagnosed with a GM Tech2 or clone, but will probably will take something to read non ECM codes and status. Or the old fashion way of wiring diagrams/voltmeter to see what Isn't getting power when it should. I have a Tech2 clone if I can get it to run.

 

[Ross]

Is there any OBDii codes being thrown when the issue occurs, that are getting reset by the reboot?

 

[Robinjo]

More items: There is a battery light on the dash while it is running (after resetting the ECM). I checked the battery and it is holding 14v and checked the alternator while running, it's producing between 13.5 and 14v.

 

[jirwin]

Took the positive cable off the battery, placed the cable right back on and tried the car. Everything comes on and it'll start.

This is basically the same issue I'm having. Not sure what the issue is yet. Haven't resolved it yet

 

[Robinjo]

Is there any OBDii codes being thrown when the issue occurs, that are getting reset by the reboot?

I'm getting the following codes, they stay even after rebooting. I added notes for things in ITALICISED font. I cannot check the codes while the issue is occurring as the OBD-2 port doesn't get power.
C1000 (no description)- Manufacturer controlled DTC from the internet?
C1206 (no description) - Nothing on the internets here
C0904 Ignition Switched Power Relay #1 Circuit/Range Performance
P0404 EGR System - Range Performance Problem
P0141 Heated Oxygen Sensor (H02S) Bank 1 Heater Control - Circuit Malfunction (looks like my O2 Sensor maybe done?)
P0135 Heated Oxygen Sensor (HO2S) Bank 1 Heated Control - Circuit Malfunction
P0650 Malfunction Indicator Lamp (I do not have my lights hooked up yet?)

P0443 EVAP - I removed the Evaporative Emissions System
P0452 EVAP
P0449 EVAP

This is basically the same issue I'm having. Not sure what the issue is yet. Haven't resolved it yet

If you figure it out I'd love to know!!! Maybe we'll find out here together.

 

[Gtstorey]

You need to check the C codes to the service manual for your model, probably available in Alldata. None of those C codes are applicable to the later model cobalts.

 

[Robinjo]

Thanks for the idea. I’ll look at that.

 

[Gtstorey]

Does it start by just clearing the codes?

 

[Robinjo]

I don’t know. Nothing gets powered because it’s all shut down when doing the no start. I could clear them while it’s reset though

 

[Robinjo]

So after a little digging this is what I've come up with. The P0650 and C0904 are two I'm not sure on.
C1000 (no description)- Manufacturer controlled DTC from the internet? Not listed on AllData. Internet listed as Brake Lights Issue, I do not have those connected yet.
C1206 (no description) - Nothing on the internets here Not listed on AllData. Internet listed as ABS/Wheels Speed Sensor Issue, do not have those either.
C0904 Ignition Switched Power Relay #1 Circuit/Range Performance. Also nothing on AllData. Internet defined as Clutch Position Issue or Fuel Rail Pressure too High
P0404 EGR System - Range Performance Problem
P0141 Heated Oxygen Sensor (H02S) Bank 1 Heater Control - Circuit Malfunction (looks like my O2 Sensor maybe done?) I've ordered another O2 Sensor, probably needs replacing anyways.
P0135 Heated Oxygen Sensor (HO2S) Bank 1 Heated Control - Circuit Malfunction
P0650 Malfunction Indicator Lamp (I do not have my lights hooked up yet?)