08 Yukon Engine Stalled

[Kevin Killinger]

Hello

I've only owned my 08 Yukon Denali for 30 days. Purchased it from out of state and it appeared to have a pretty good CarFax report. Anyway, yesterday the vehicle stalled on a busy road. I still had all electrical power but the engine would not turn over at all. After sitting for a few minutes it would then start and make it a few more miles and would stall again. Again after a few minutes the vehicle would start and I was able to make it to a GMC dealership where it stalled for a third time in the parking lot. Of course with it being Christmas they cannot look at it until Monday. Vehicle has 124k miles. I've replaced the battery and alternator as a preventative measure. This was done a few weeks ago. I've only been driving the vehicle around town and yesterday was the longest trip it has been on since I've owned it. Any ideas???

 

[eagle-co94]

Sounds like some kind of ignition module issue. Hopefully that'll be a cheap and easy fix. My 08 Tahoe is only about 8k miles behind you but I don't plan on having mine more than a few months longer so fingers crossed I'm not that close to it happening.

 

[iamdub]

What does "turn over" mean? That the engine would (crank) spin when you turn the key but not fire or that it wouldn't crank at all when you turned the key?

 

[eagle-co94]

From my understanding, turn over means exactly that, the motor will not turn by engaging the starter.

 

[Kevin Killinger]

What does "turn over" mean? That the engine would (crank) spin when you turn the key but not fire or that it wouldn't crank at all when you turned the key?

Sorry, wouldn't crank at all when I turned the key.

 

[iamdub]

From my understanding, turn over means exactly that, the motor will not turn by engaging the starter.

I have to ask cuz I've heard people say things like "it'll crank but won't turn over", as if "turn over" means for it to fire and try to start/run.

Sorry, wouldn't crank at all when I turned the key.

Not what I was hoping to hear. But my first troubleshooting would be to check for spark since all that requires is a screwdriver. I'm also inclined to believe it's temperature-related, like something electronic is getting warm and a circuit is opening like a cracked solder joint on a circuit board. Have a heat gun? Maybe start it when it's cold and heat up the PCM to see if it dies shortly.

 

[retiredsparky]

Using the heat gun requires a gentle touch. Some of them put out 700* plus. A safer way is to have a couple of cans of canned "air" like what is used for cleaning pc's. When the car breaks down, spray the pcm with the canned air for several minutes to cool it down and see if it starts.

Checking for codes is good too. No mention was made of an mil (maintenance indicator lamp) showing on the dash, although codes can be stored without the mil.

My guess is there is a loose, corroded electrical connection at the battery or a ground location. Another remote possibility is an intermittent connection in the fuse block.

You have eliminated the battery and alternator.

 

[Kevin Killinger]

Using the heat gun requires a gentle touch. Some of them put out 700* plus. A safer way is to have a couple of cans of canned "air" like what is used for cleaning pc's. When the car breaks down, spray the pcm with the canned air for several minutes to cool it down and see if it starts.

Checking for codes is good too. No mention was made of an mil (maintenance indicator lamp) showing on the dash, although codes can be stored without the mil.

My guess is there is a loose, corroded electrical connection at the battery or a ground location. Another remote possibility is an intermittent connection in the fuse block.

You have eliminated the battery and alternator.

Sorry I forgot to mention that the mil did come on and stay on when the first stall happened. I had to leave it at the dealership and will hopefully hear from them tomorrow. I'll keep everyone posted on the outcome. Merry Christmas

 

[Kevin Killinger]

Hey guys

Here's an update:
Code P0449 (Canister Vent Device)
Code P0601 (ECM Internal Device)

I'm waiting for the after market warranty center to open tomorrow to see if they will cover replacement on the above items.

 

[eagle-co94]

I'd say the ECM should be covered but doubt the carbon canister is.