[Mcardenal]

Hello folks,

Have a 2018 Zl1 10 speed with about 18k miles with original battery.
Long story short is I don't drive it often and went about 4-5 weeks without driving it. Battery was completely dead and would not take a charge.
Replaced it with a new battery and nothing has been right since. These are the codes I'm getting and a video of the throttle body clicking after the car is turned off. Traced it back to the ECU relay......



I've had to disconnect the battery a few times to visually inspect and clean connections and all look good. The car cranks but doesn't start at first but then it does.

Thanks in advance for all your help.

Drove it and it runs fine and transmission shifts fine....

[Mcardenal]

forgot to mention that the check engine light flickers in Rythm with the relay clicking.

[MyNameIs]

Originally Posted by Mcardenal

Hello folks,

Have a 2018 Zl1 10 speed with about 18k miles with original battery.
Long story short is I don't drive it often and went about 4-5 weeks without driving it. Battery was completely dead and would not take a charge.
Replaced it with a new battery and nothing has been right since. These are the codes I'm getting and a video of the throttle body clicking after the car is turned off. Traced it back to the ECU relay......



I've had to disconnect the battery a few times to visually inspect and clean connections and all look good. The car cranks but doesn't start at first but then it does.

Thanks in advance for all your help.

Drove it and it runs fine and transmission shifts fine....

Probably a faulty connection somewhere. Clear all your codes and see if they come back.

[Mcardenal]

Thanks for your quick feedback.
It definitely feels like something is shorting. But why isn't it blowing a fuse?
I have already gone through any harness I have access to and checked the grounds in fron and at the battery. I also added a second ground strap from the front OEM ground post to the engine block.
Any ideas on where else to look?

[CalgaryZL1]

Originally Posted by Mcardenal

Thanks for your quick feedback.
It definitely feels like something is shorting. But why isn't it blowing a fuse?
I have already gone through any harness I have access to and checked the grounds in fron and at the battery. I also added a second ground strap from the front OEM ground post to the engine block.
Any ideas on where else to look?

I would swap out the suspect relay

[MyNameIs]

Originally Posted by Mcardenal

Thanks for your quick feedback.
It definitely feels like something is shorting. But why isn't it blowing a fuse?
I have already gone through any harness I have access to and checked the grounds in fron and at the battery. I also added a second ground strap from the front OEM ground post to the engine block.
Any ideas on where else to look?

Might not be enuff current to blow it if its weak. You sure you new battery is good? A weak battery can throw all types of codes.

[Mcardenal]

Originally Posted by CalgaryZL1

I would swap out the suspect relay

Thanks for the idea. I did that and it exhibited the same behavior on the new relay. Almost $30 BTW!

[Mcardenal]

Originally Posted by MyNameIs

Might not be enuff current to blow it if its weak. You sure you new battery is good? A weak battery can throw all types of codes.

I’ve been thinking that also recently. Im going to pull the new battery and charge it on a AGM charger. Hope it works

[CalgaryZL1]

You should look into your alternator, make sure it’s charging properly.

[Spaceme1117]

Another thing to consider is that the new battery could be faulty. It does happen so don't rule this out.

[Mcardenal]

Originally Posted by CalgaryZL1

You should look into your alternator, make sure it’s charging properly.

Thanks for the feedback.
Checked alternator voltage and its ok.

[Mcardenal]

Originally Posted by Spaceme1117

Another thing to consider is that the new battery could be faulty. It does happen so don't rule this out.

Everything seems to check out on the battery voltage wise. But im going to go to the store and ask for an exchange this week and see what happens.

Thanks,

[Mcardenal]

No luck with this issue. Now i have another weird issue popping up. I turn the vehicle "off" but the engine keeps running. The only way i can get to turn off is by removing the fuel pump relay.....

[Techman]

Where is this stored for the periods of non use? At this point I would start looking for possible rodent damage to wiring.