hello, problem with Hybrid Escalade 2010. Service Hybrid System error on dash about 3 weeks. But all works till now.
Drived on the rainy highway, service stabiltrak message comes, then service battery charging system then all disapears.
Few minutes later service stabiltrak and engine power reduced. No power at all. Loud whining noise when stop on crossroad, when start driving again noise is gone. Drived to home slowly, because no power at all, removed battery power for 10 seconds. Restart the car and everything seems ok. Next morning cant start the car. Only ignition on and Service Hybrid System and Service Battery Charging system messages.

Scanned the car today.
Found these faults: Here is OneDrive link

 

Lots of "communication errors" suggest 12V battery and/or corroded cables/connections.

"not learned" errors are likely due to recent 12V disconnect.

 

battery charged whole night. I see that charging time about 3 hours. In the morning still same. No start, but no Service charging system error anymore on dash. If i try to start the car then it wants to start but no start.
Then i lift the car and open all connectors what i see under the car plus ecu connectors. All was clean and dry. Connected all back. And car starts. Strange. Can it be that 12v battery is bad?

only one fault is right now. Service Hybrid System error on dash.
Tech2 shows me one fault in SDGM (Serial Data Gateway Module) - B1000 Symptom 39. ElectronicControl Unit Performance Internal Electronic Failure

 

Man that is easy with a Tech2, not everyone has access to that tool. Sounds like your vehicle will be good once you replace the SDGM.

 

So today again same error. But first message in dash was Service brakes soon. After that message no power. And after that service battery charging system and so on like last time.

 

so have you replaced the SDGM yet? I thought that is what the tech2 said your issue was????

 

not changed yet. 2010 escalade cranks few times but no start. Hybrid battery 248v, but cant use Jump assist. If i turn it ON with Tech2 and turn ignition OFF then after 1 second i get message on dash that Jump Assist aborted. 2 times was when i turn jump assist on then Hybrid battery voltage drops to 12V. After few minutes ignition off then 248v again.
I think that maybe i order these 2 items: 24251562 APM and 25883951 SDGM. But cant find good place in US where i can order it. I need to ship it to Estonia.


Now i have problem with another Esalade hybrid also. 2012 year. And 1 DTC in APM. Car starts fine but no 12v power. No battery charge, no power steering etc. APM dead?

 

248V on HV battery is dead flat. Any resting voltage at or under 288V is dead flat. I wouldn't consider anything under 296V as acceptable to attempt start.

 

yes i understand. But if i read service manual then Jump Assist should work 240v or higher. I have 248v so it should work. How i can charge battery? All works before car stop working one morning.

 

2010 Hybrid works now. I removed battery terminals for 30 seconds and after that i can jump assist. 1 hour charge and car starts.