V1 Intermittent No Power/Start

[jirwin]

This just started again recently. No lights or anything when the key is turned. I take the negative terminal off, and put it back on, and power returns. Jumping makes no difference. I assume this is a low battery or short safety. When this first happened, my terminals were loose. I replaced them with Duralast Gold ones and haven't had a problem since. The other day I left the key on while doing something, and the issue returned. Same procedure to get it to start. Battery is charged (reading 12+), so I assume the terminals are making bad contact again? Does anyone know what this safety I'm running into is?

 

[jirwin]

Just did it again leaving the gym. Take negative off, put it back on, good to go.

 

[Gtstorey]

I'm not aware of any "safety" that will cause this. It's probably going to take some careful work with a voltmeter to figure out what is going on. Might be a loose connection at the BCM that remakes a connection when messing with the battery. I had a few times that mine would act totally dead and a stomp on the floor near the BCM would make it work again. Reseating the BCM connectors made and adding a zip tie fixed it since last fall.

 

[Desert Sasqwatch]

The ECM/BCM monitors battery voltage and possibly current, depending upon donor model used. A weak battery may be sensed and it could be preventing powering on certain systems - or I could be reading too much into some Dr. Google information from the Cobalt forum.

If it's a weak battery, it maynot able to output sufficient current to turn the starter? The battery may show good voltage - at least 12.4V - but it takes about 50 or more amps of current to start the car. Can you swap a battery from another vehicle temporarily to check for good current output?

 

[Gtstorey]

Do things light up and it just doesn't turn the starter over?

 

[jirwin]

The ECM/BCM monitors battery voltage and possibly current, depending upon donor model used. A weak battery may be sensed and it could be preventing powering on certain systems - or I could be reading too much into some Dr. Google information from the Cobalt forum.

If it's a weak battery, it maynot able to output sufficient current to turn the starter? The battery may show good voltage - at least 12.4V - but it takes about 50 or more amps of current to start the car. Can you swap a battery from another vehicle temporarily to check for good current output?

Exactly what I'm thinking. It definitely has that cuff around the negative cable that reads something. Battery has been abused though, so maybe its just weak.

Do things light up and it just doesn't turn the starter over?

No, nothing at all. No lights, fuel pump, anything. Like there's no battery

 

[Gtstorey]

Weak batteries can do weird things and when it comes to questionable batteries, I replace them since I had a Saturn once that I blame a weak/bad battery on ruining the BCM & ECM at the same time.

That said, I doubt that is keeping everything from coming on. I forgot to connect my alternator on my Goblin last fall after doing some work, drove it until it cut off before I realized it and everything would still light up and you could hear various relays click, it just didn't have enough to turn the starter over. Of course you don't have your donor in your signature so I don't know what you are working with. The LNF didn't have the current sensor at the battery that some of the others have, so maybe your is different.

If it's actually something with the negative cable, have you checked the connection on the other end? Maybe the wires are corroded under the insulation badly enough that they are broken (doubtful but not impossible).

 

[jirwin]

Took it to Autozone and they said it tested fine. Frustrating. I might just bite the bullet and buy a new one.

 

[Gtstorey]

Will the low beam headlights cut on when it is in the no run condition? The later models at least, ground the low beam relay directly through the light switch and the high beam goes through the bcm. If no low beam then you have a power supply or ground issue. If you have low beam but not hi then you have an issue with the bcm connection or the supply/ground for the bcm.

 

[Robinjo]

Just curious if the vehicle can be push started when this condition is occurring?

 

[Gtstorey]

Just curious if the vehicle can be push started when this condition is occurring?

not likely if he is not hearing the various relays and fuel pump not working.

 

[Robinjo]

That would tell if it’s battery/starter related or electrical connection related.

 

[Sluggonaut]

If it's actually something with the negative cable, have you checked the connection on the other end? Maybe the wires are corroded under the insulation badly enough that they are broken (doubtful but not impossible).

I'd start with the cable, especially if disconnecting and connecting the cable addresses the symptom. You can check the resistance on your other grounds when it's running/not running to see if there's a difference.

 

[jirwin]

It did it again last night when I went to take it to Autozone to have the battery checked. Ended up taking it out and taking my truck. It was worse this time. When I popped the negative on and off it powered up. I latched the hood back down (~1 minute) and then it stopped working again. Two extra things to add to the list of symptoms.... I have 2 ways I can measure voltage. One is directly from the ECM via my OBD2 digital dash. The other is via a USB charger I installed with a built in voltage indicator (behind a relay). On the way home from the gym it read ~14.5 on the digital dash, but 11.6-11.8 via the USB charger - both while driving. Maybe it is a bad battery? Makes me think its trying to charge the battery and can't or something, idk.

Also, these are my terminals, if anyones curious. Really like them. Cleaned up my wiring a lot.

https://www.autozone.com/batteries-starting-and-charging/battery-terminal/p/duralast-positive-battery-terminal/374187_0_0

https://www.autozone.com/batteries-starting-and-charging/battery-terminal/p/duralast-negative-battery-terminal/388120_0_0

 

[Desert Sasqwatch]

The OBD voltage is what the ECM/BCM will be sensing, not low, but just a little higher than the 14.2ish volts the alternator will be nominally outputting to the battery - so your alternator is working. The slightly high voltage also is an indication of the electrical system drawing current, either battery charging or operating electrical load. Since Autozone stated your battery is okay, the next area of concern is wiring and connections, as had been stated in the previous posts above.

The first obvious thing that most everyone hits on are the grounds. Metal to Metal contact, tight connections, and no frayed - barely there - wires on the positive and most importantly on the negative cables.

One thing to try is use a set of jumper cables to connect the engine fuse box directly to the battery terminals, leaving the Goblin battery cables connected. The 'red post' (capped) on the top of the fuse box to the battery positive (first connection) and the battery negative connected to the frame or engine block. You should see no sparking when hooking them up - otherwise there is a difference in potential (resistance) where there should be none. Stop if you see this and look for power cable issues. Otherwise start the car and turn it off a few times in this configuration to see if it makes a difference.

 

[Gtstorey]

Use a digital voltmeter at the jump post to good ground. And depending on what you got for the usb/voltmeter, I had one in a different vehicle and I didn't run it long before it started reading a low voltage, so I wouldn't count on that to much without some confirmation it's correct.

 

[Scott #321]

I would concur with the ground issue 1st. Make absolutely the ground cable from the neg to the frame is good. simply removing and reinstalling the negative cable should not do this unless there is a bad connection and since you have installed and removed the neg multiple times I would assume it is elseware. The other end of the negative cable is getting moved with every install and could be just enough to start working again until the next time. The other option is if you get it to happen again to move cables and grounds around with something on (headlights) and see if you can narrow down the location.

 

[jirwin]

Haven't had time to try your suggestions yet, but somewhat interesting development. @mjgrusni has his road legal now. We've done a couple rides. He doesn't get on the forum much so I know he hasn't read any of this. We met up for a car meet today and he started complaining about the same thing. Exact same symptoms I have. He has the same donor - late model XFE. Strange coincidence? We shall see.

 

[jirwin]

Finally got around to doing a little digging. Pulled DTCs with HPTuners:

0x544: B1325 - Device Power Circuit Voltage (History)
0x544: B1380 (Current, History)
0x544: B1516 - Battery Current Sensor (Old, History)
0x544: B1517 - Battery Voltage (History)
0x544: B2555 (History)
0x544: B2645 - Ambient Light Sensor Circuit (Current, Old, History)
0x544: C0277 (History)
0x544: U2100 - CAN Bus OFF (History)
0x544: U2105 - CAN Bus Error ECM (History)
0x544: U2111 (History)
0x544: U2113 (Current, History)
0x544: U2116 (Current, History)
0x544: U2125 (History)
0x544: U2137 (History)
0x544: U2172 (Current, History)
0x54A: U2105 - CAN Bus Error ECM (History)
0x54A: U2107 - Lost Communications with Body Control System (History)
0x7E8: P0036 - HO2S Heater Control Circuit (Bank 1, Sensor 2) (Permanent)
0x7E8: P0443 - Evaporative Emission System Purge Control Valve Circuit (SES, Pending, Current, Old, Permanent, History)
0x7E8: P0449 - Evaporative Emission System Vent Control Circuit Intermittent (SES, Pending, Current, Old, Permanent, History)
0x7E8: P0452 - Evaporative Emission System Pressure Sensor/Switch Low  (SES, Pending, Current, Old, Permanent, History)
0x7E8: P0532 - A/C Refrigerant Pressure Sensor A Circuit Low (Pending, Current, History)
0x7E8: P0573 - Brake Switch A Circuit High (Pending, Current, Old, History)
0x7E8: P0650 - Malfunction Indicator Light Control Circuit (Pending, Old)

Started digging through some of these. Before pulling codes I thought about trying to replace the battery current sensor since its fairly cheap. Might still do that, but need to do some more digging.

I've never cleared the codes, so I'm going to do that first and see what returns.

 

[Gtstorey]

Your current U codes are from eliminated modules.

B1380 is accessory switch circuit. Don’t think that will cause a no start.

P0573 means no 3rd brake light or cruise but not a no start.

clear codes and see what returns.