This weekend I made some major repairs to my Yukon. Disconnected both the hybrid battery and the 12 volt battery. Removed the exhaust manifolds and removed broken bolts. Also replaced the oil pan gasket. After repairs were completed I reconnected the batteries. Now I have a no crank condition. I have had the batteries Disconnected before, for hybrid battery refurbishment. I did not have this issue that time. Does anyone have an idea of what to look for?

 

there's a ground on the back of the driver's side head that I missed putting stuff back together once after putting one of those exhaust brackets on.

is it just completely dead? or does it give any messages or codes? do you have any way to scan it? the 300v plug has an extra step to installing it that people miss some times too.

 

 

???, I did not have to take any grounds off of the engine. The headlights, radio, dome lights ect. Come on with the key. But when I turn to the start position, they all go off. Let key back to tge run position and they will come back on. I have the following messages that scroll in the display: Service Hybrid System; Service Power Steering; Service Stabilitrac; Service 4wheel drive system, Engine is hot, A/C is inop. It has a new Greenbean Battery last summer as well as the 12V battery at the same time. Started fine after changing them. Also 3 years ago I had the hybrid battery out for 3 days to have some bad cells replaced. It also started up right away.

 

that's a lot of stuff. just having the battery disconnected shouldn't cause any trouble, I've had mine disconnected for a while before too.

other than making sure your 12v battery is fully charged, these trucks do weird things when the 12v is weak. do you have any engine covers off? especially the one over the inverter under the hood, it has to be on or it won't start.

are you sure you put the plug in correctly?

https://youtube.com/shorts/PKvIqdFPzkw?feature=share
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if all that is good, unless anyone has any more ideas you're going to have to double check everything you've touched and hope you missed something. if not, then this time to start troubleshooting. buy a tech 2 and start going thru the diagnostic steps in the shop manuals.

 

??? Thank you so much. I was forgetting to push the lock down on the orange connector. Now the only messages are 'service power steering' and 'service 4 wheel drive'. But it does start now. I had ti take the front diff and steering rack out to remove the oil pan. I will double check the connections this evening. Thanks again!!!

 

glad it worked.

I've heard on the non hybrid ones that when you pull the rack the light comes on for a bit and then kinda resets itself and stays off after driving for a bit and clearing it. not sure if ours is that way thou.
​​​​​​no clue on the 4wd code.

hopefully alls good