'11 Yukon Electrical Issues

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CapnCrunch

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Hi all,
I've read some the threads that somewhat relate to my issues... mine seem much more intense.
First- vehicle is '11 Yukon SLT w/ approx 95K miles, new to us 15 months ago. Shortly after purchase @ 70k miles (and I suspect for previous owners as well, as we purchased under book value from a dealer) the electrical started acting odd. The whole dash will "flash." I use this term to describe a host of events that culminate in the same problem... sometimes it's just a seatbelt light that comes on and flashes for a second or two, to as severe as "Service stabilitrac" light coming then leaving. My wife and I have come to understand what this all means... after stopping the rig and turning the key off the entire vehicle is electrically dead-no lights, no horn... just dead (except a rapid, faint clicking noise from the driver's door) which requires simply opening the hood and lifting on the negative battery cable and putting it back... rig will start and do fine until the next episode.

To save a few posts at least, have had it into a local battery store chain, also Les Schwab, PNW tire chain w/people I've done business with for years... all say battery is good, replace battery cables. But at least at Les Schwab I was able to get the issue to duplicate w/service tech there (when event signaling event was imminent stopped in and left motor running until he came out.) He witnessed the vehicle at shutdown go dead, me touch battery cable, vehicle start and run fine... he had me shut it down, tested battery w/and w/o load... had me start again, shut it down and then he inspected and tested security of all connections (including reefing on negative cable thinking it was a loose connection) all to no issues apparent.

I seek advice as the issues this week have escalated to the point of feeling maybe it's becoming unsafe to drive... the last time something happened (yesterday) the whole dash went dead, all gauges went to zero, flashed to full as if just started, vehicle acted as if it shifted to neutral (motor revved up as if out of gear.)

One thing that is possibly more related to (noobi-ness warning!) fuel saver system that turns off 4 cylinders... vehicle surges somewhat without that system actually switching from 8 to 4 or visa versa.

I forgot to mention... other signaling symptoms are lights - sometimes dash, headlights, interior lights - varies at random.

That's my story, looking for insight from the more experienced with these modern marvels that always seem more complicated but not always for the better.

Mark
 

swathdiver

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Hi all,
I've read some the threads that somewhat relate to my issues... mine seem much more intense.
First- vehicle is '11 Yukon SLT w/ approx 95K miles, new to us 15 months ago. Shortly after purchase @ 70k miles (and I suspect for previous owners as well, as we purchased under book value from a dealer) the electrical started acting odd. The whole dash will "flash." I use this term to describe a host of events that culminate in the same problem... sometimes it's just a seatbelt light that comes on and flashes for a second or two, to as severe as "Service stabilitrac" light coming then leaving. My wife and I have come to understand what this all means... after stopping the rig and turning the key off the entire vehicle is electrically dead-no lights, no horn... just dead (except a rapid, faint clicking noise from the driver's door) which requires simply opening the hood and lifting on the negative battery cable and putting it back... rig will start and do fine until the next episode.

To save a few posts at least, have had it into a local battery store chain, also Les Schwab, PNW tire chain w/people I've done business with for years... all say battery is good, replace battery cables. But at least at Les Schwab I was able to get the issue to duplicate w/service tech there (when event signaling event was imminent stopped in and left motor running until he came out.) He witnessed the vehicle at shutdown go dead, me touch battery cable, vehicle start and run fine... he had me shut it down, tested battery w/and w/o load... had me start again, shut it down and then he inspected and tested security of all connections (including reefing on negative cable thinking it was a loose connection) all to no issues apparent.

I seek advice as the issues this week have escalated to the point of feeling maybe it's becoming unsafe to drive... the last time something happened (yesterday) the whole dash went dead, all gauges went to zero, flashed to full as if just started, vehicle acted as if it shifted to neutral (motor revved up as if out of gear.)

One thing that is possibly more related to (noobi-ness warning!) fuel saver system that turns off 4 cylinders... vehicle surges somewhat without that system actually switching from 8 to 4 or visa versa.

I forgot to mention... other signaling symptoms are lights - sometimes dash, headlights, interior lights - varies at random.

That's my story, looking for insight from the more experienced with these modern marvels that always seem more complicated but not always for the better.

Mark
Hi Mark,

A bad cell in a battery can be hard to detect and such wreaks the kinds of havoc you are experiencing. How old is the battery? If the cables are not rotten and the battery and grounds are good, chances are the Body Control Module is in need of replacement but I'm making an educated guess from my chair and don't have my Tech-2 hooked up to your truck. Welcome to the forum by the way, nice boat!
 
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CapnCrunch

CapnCrunch

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Hi Mark,

A bad cell in a battery can be hard to detect and such wreaks the kinds of havoc you are experiencing. How old is the battery? If the cables are not rotten and the battery and grounds are good, chances are the Body Control Module is in need of replacement but I'm making an educated guess from my chair and don't have my Tech-2 hooked up to your truck. Welcome to the forum by the way, nice boat!
Hello swathdiver, thanks, we love the boat, but engine issues are preventing enjoyment currently - but that's I suspect a different forum! :)

Body control module... is that a common issue with these? I was told by a Les Schwab (being from Florida that company may not be familiar - think Firestone Tire Centers, but West, Midwest company, I think like 500 stores, and they don't do complete auto repair) who had a '12 Tahoe that it's a known but somewhat rare defect... she went through the same exact issues - had all battery and a harness replaced... after it still acted up she traded it off for a dodge lol.

Battery is less than 2 years old - replaced by the dealer (Northwest Motorsports, partially owned by a NW baseball legend, Jay Buhner from the Mariners) a few months b4 I purchased... I suspect because of the symptoms I'm facing.

I'll look up the how and where of that module and try it... crossing fingers!!
 

swathdiver

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Hello swathdiver, thanks, we love the boat, but engine issues are preventing enjoyment currently - but that's I suspect a different forum! :)

Body control module... is that a common issue with these? I was told by a Les Schwab (being from Florida that company may not be familiar - think Firestone Tire Centers, but West, Midwest company, I think like 500 stores, and they don't do complete auto repair) who had a '12 Tahoe that it's a known but somewhat rare defect... she went through the same exact issues - had all battery and a harness replaced... after it still acted up she traded it off for a dodge lol.

Battery is less than 2 years old - replaced by the dealer (Northwest Motorsports, partially owned by a NW baseball legend, Jay Buhner from the Mariners) a few months b4 I purchased... I suspect because of the symptoms I'm facing.

I'll look up the how and where of that module and try it... crossing fingers!!
No, it's not a common part to fail but they do go bad sometimes. It has to be programmed to your VIN and is under the driver's side dash.

If you do your own work or diagnosis, a Tech-2 is indispensable, the most important tool in your kit for working on these.
 
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CapnCrunch

CapnCrunch

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Thanks muchly... is there a specific obd-2 reader you'd suggest, or will any generic do the same? I find them on Amazon ranging from +?- 60 to (gulp) 3k... and will it allow me to program to vin myself?
 
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CapnCrunch

CapnCrunch

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Hi again all... absent for a bit as I'm still chasing gremlins in my boat that happens to have a gm 350 tbi system (uggh)... things today soured on the Yukon, it's totally dead and no amount of tinkering brings it back. Battery charger when connected gives a green light, starts charging, there's a click that I can't locate under the hood, and battery charger shuts off w/green "good to go" light back on.

Any specific fuses maybe that might kill entire system electrical like that?

Thanks to any and all that might have a suggestion.

Gonna pull the battery tonight to get it tested in the morning, however battery has always tested (even just weeks ago) good.
 

wsteele

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I think the only reason the charger turns off is it is sensing the battery is fully charged, none of the trucks electronics would cause it to shut off prematurely. What does a voltmeter say the battery voltage is, just after the charger is done?
 

Doubeleive

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so... did you ever do what was initially suggested? (replace battery cables)?
you can do a draw down test on the positive battery cable, connect your meter to a good ground, touch the positive cable at the starter and have some one try to start the vehicle, if the voltage is 10.5v or less (while trying to start), replace the cable. I would also replace the ground, these cables can corrode from the inside and look perfectly normal from the outside.
 
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CapnCrunch

CapnCrunch

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so... did you ever do what was initially suggested? (replace battery cables)?
you can do a draw down test on the positive battery cable, connect your meter to a good ground, touch the positive cable at the starter and have some one try to start the vehicle, if the voltage is 10.5v or less (while trying to start), replace the cable. I would also replace the ground, these cables can corrode from the inside and look perfectly normal from the outside.
I didn't - at the time it was an irritation, and was trying to get the boat ready for an extended trip upriver. Today is when it changed for me... everything going dead with no recovery.

Today I ran across the following thread:

seems like it's more a mfr defect that still hasn't been addressed fully. At any rate, tonight I put a new multi meter across the battery - read 4.8v while connected, 10 volts w/negative cable disconnected. Put a charger on the battery and am hoping in the morning that combined with a thorough cleaning and tightening of all connections might solve my problem... as was mentioned in noted thread above.

Mark
 
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