2010 Yukon Denali - 2 Issues

[soulsea]

So I've now had a chance to drive her around all weekend and two things have emerged that I need to figure out if they're normal of if they need addressing. For the record the truck has 18000 (Texas) miles so any remedy will be covered under warranty.

1. I am getting the headlight dimming thing when electrical stuff gets engaged in the truck. For example when the power steps activate the headlights will dim. I'd have thought late model vehicles would not have crappy alternators like days of old. The 09 Hybrid never had this. Normal, not normal, remedy?

2. The Hybrid has an incredibly smooth 6 speed variable transmission, never felt a shift. I was under the impression the Denali had the same one. Yet my truck has a noticeable sag/slight hesitation on the upshifts. I read somewhere that the earlier trucks with the 4 speed had this issue and it was remedied by a program upgrade/calibration of the TCM (transmission control module). Anyone with the 6.2 experience this? Normal/not normal?

I'm going to drive it by the dealer so they can drive around with it with the scan tool on, but I'm just curious if anyone is experiencing these things?

Thanks.

 

[THE YETI]

Serge...

When amperage is drawn it is not uncommon for the lights to dim down until the power is restored. Those powersteps draw alot of current.

Your transmission now has torque management. hesitation is common. The only remedy to that is Blackbear tune. You can eliminate most of the torque management and get rid of the lag. You dont necessarily have to have a hard firm shift, but you can certainly eliminate that lag. We did this to our suburban.

 

[soulsea]

Mmm thanks Robbie ...

I figured the steps are power heavy. I'm going to fidget with other stuff later tonight to see if anything else dims the lights. Out of curiosity, is there some type of upgrade that can be done to remedy this?

Btw, I don't know if this is related, but I was looking at some H13 over-wattage headlight bulbs the other day and ran into this listing http://www.rallylights.com/detail.aspx?ID=2448 with this hysterical disclaimer: The H13 is quite possibly the stupidest design for a bulb ever foisted on the public. The terminals are so small that they overheat, even at stock wattages, and melt the plastic housing of the connectors. Higher than stock wattage bulbs are offered, but not recommended and we accept no responsibility for their use.

After some inquiries it turns out that because of the nature of the bulbs, making a halogen harness for these bulbs youre limited to 16ga, or at MAX 14ga wire simply due to the size of the connector/terminals. http://www.hidplanet.com/forums/showthread.php?43711-H13&p=453715&viewfull=1#post453715

So perhaps there's a correlation there between the harnesses and the dimming.

As far as the upshift lag, it's reassuring to know that it may be normal for these trucks ... although I'm left to wonder why the HyHoe did not suffer this. Plus, it's aggravating.

 

[THE YETI]

I'm pretty sure that your HyHoe had a completely different drivetrain setup because ofit being a Hybrid. I have noticed that most Hybrids have little to no shift feeling.

I am not sure if it will remedy the situation, but look into the "Big 3" upgrade, where you upgrade the ground and power wires for the vehicles electrical system. It is supposed to help. Small wires can only draw so much power, so the thicker upgraded wires should indeed help.

FWIW, our headlights dim when the electric fans kick on. Only for a second, then they re-up, but its just because of the high amperage draw and the sudden "bump" when it kicks on.

 

[edgaranah1]

I'm pretty sure that your HyHoe had a completely different drivetrain setup because ofit being a Hybrid. I have noticed that most Hybrids have little to no shift feeling.

I am not sure if it will remedy the situation, but look into the "Big 3" upgrade, where you upgrade the ground and power wires for the vehicles electrical system. It is supposed to help. Small wires can only draw so much power, so the thicker upgraded wires should indeed help.

FWIW, our headlights dim when the electric fans kick on. Only for a second, then they re-up, but its just because of the high amperage draw and the sudden "bump" when it kicks on.

+1 on the headlights dimming when the fans kick in.

Sent from my BlackBerry 8530 using Tapatalk

 

[KMeloney]

Serge-- the 6-speed in these trucks blows. I could have told you that. Wait, I HAVE said that a million times here.

Hold on... The 6-speed blows.

There you go -- 1,000,001.


Sent from my iPhone using Tapatalk

 

[THE YETI]

Doesn't Serge have a 6L80? As opposed to your 6L60? I'm not well versed on those, but I was sure the 6L80 was pretty stout tranny?

 

[soulsea]

Yes my transmission is the 6L80.

 

[felixgun]

So I've now had a chance to drive her around all weekend and two things have emerged that I need to figure out if they're normal of if they need addressing. For the record the truck has 18000 (Texas) miles so any remedy will be covered under warranty.

1. I am getting the headlight dimming thing when electrical stuff gets engaged in the truck. For example when the power steps activate the headlights will dim. I'd have thought late model vehicles would not have crappy alternators like days of old. The 09 Hybrid never had this. Normal, not normal, remedy?

2. The Hybrid has an incredibly smooth 6 speed variable transmission, never felt a shift. I was under the impression the Denali had the same one. Yet my truck has a noticeable sag/slight hesitation on the upshifts. I read somewhere that the earlier trucks with the 4 speed had this issue and it was remedied by a program upgrade/calibration of the TCM (transmission control module). Anyone with the 6.2 experience this? Normal/not normal?

I'm going to drive it by the dealer so they can drive around with it with the scan tool on, but I'm just curious if anyone is experiencing these things?

Thanks.

The 6.2L is infamous for this laggy shifting. Unfortunately it is consistent with most 6.2L's as I've heard a lot of people gripe about this issue. Is it normal? Surely not but to GM it is... My Esky does it too. Fix = BB Tune.

 

[soulsea]

Mmm I see, thanks Felix.

Just so I don't get us confused as the term 'lag' could be interpreted in many ways. Basically the upshifts, instead of being smooth and seamless, create almost what one could call a slight hesitation. It's like it gets bogged down just when it needs not to for the upshift.

Is that what we're talking about?