Tahoe hybrid won’t stay running
 

Hey my name is George. I currently own a 2008 Chevy Tahoe. when I crank the engine it stay running for about 10 to 15 seconds and then it dies. after that it just crank a little bit but it doesn’t fire up , if I wait 2 to 3 hours it will do the same thing, I don’t have any codes, any help will be appreciated. Thanks!

Re: Tahoe hybrid won’t stay running
 

The Hybrid system fools a lot of people in the same exact manner. The engine is actually cranked via a dampener assembly (The Two Mode 2ML70 trans uses a dampener in place of a torque converter)
The engine is cranked by one of the two transmission interior electric motors at a high rpm and what you are seeing is just the engine being turned over at around 700 to 800 rpm it NEVER actually starts. You have a engine problem probably just a bad fuel pump etc. Now that you know what to look for it should be an easy fix.

Re: Tahoe hybrid won’t stay running
 

you are having engine issues
the only way to know for sure it to see the live data stream

Re: Tahoe hybrid won’t stay running
 

there is a TSB

It Says Operator Error

Stall During Shift Out of Park Immediately following Engine Crank

This is a normal operating characteristic. Some drivers are able to interrupt the engine start sequence by immediately shifting the transmission out of Park after turning the ignition to Crank. Because the electric motor spins the engine so fast, the engine may appear to be running immediately after Crank but the ECM has not yet started spark and fuel. The ECM will turn off fuel and spark to the engine if it is not running and the transmission has been shifted out of Park or Neutral. Inform the customer to wait 1-2 seconds before shifting out of Park or Neutral to ensure that the engine is running and has completed the start sequence.
Engine Restarts in Reverse/Manual Mode from Auto Stop

if it's still not starting it's not doing the start up sequence

not getting fuel or spark

Re: Tahoe hybrid won’t stay running
 

It looks like I have the exact same problem. After turning the key, I hear the operation of the electro motor arrow rises but the gasoline engine does not start for this reason the electric motor shuts off after about half a minute

Re: Tahoe hybrid won’t stay running
 

Hi George, we are currently facing the same issue. Our mechanic has advised that the hybrid battery is failing us!

Re: Tahoe hybrid won’t stay running
 

you will be swapping out for nothing

I would look at the 12V+ battery first before anything else


I would try and use starting fluid

it's basic trouble shooting like a normal ICE
he is trying to scam you into buying a HV battery it would not even spin the electrical motor if it was bad

also make sure the engine crank shaft is spinning other wise the connection to the transmission has failed (you can see the belt spin)


try via remote start

Be careful of the fans and spinning objects

Re: Tahoe hybrid won’t stay running
 

You are right. It was my 12 volts battery. Thanks!

Re: Tahoe hybrid won’t stay running
 

I have a question because I have a 08 Tahoe that cut off on me at the top of a road. When I got it home it would start for about seconds then turn off then it wouldn’t do anything at all if I wait it will do the same thing. Now it won’t turn over or anything. And do all hybrids make a noise when they first start up?

Re: Tahoe hybrid won’t stay running
 

by noise do you mean start the gas engine? then yeah they always start the gas engine at start up. runs for longer when cold and only about 30sec something when already up to temp. but it does need to run the engine, they won't act like say a volt that just turns on in electric mode and goes. also if the hood is open it will always run the engine and not go into auto stop electric mode.

from this thread it sounds like checking the 12v is the easiest thing to do. they seem to cause people random trouble. I guess I got lucky, when my 12v went dead, it just died. the truck wouldn't start, nothing funny happened before or after, just tested it and it was dead, like 6v or something bad. replaced it with another I had laying around it it's been fine since.