2009 Yukon XL Denali - Random No-Start Condition

[KraftMatic87]

Hello all, I’m looking to get some help diagnosing an issue I’m having. Occasionally when I turn my key to start my truck, I get a single click, and then no dash lights or chimes at all. If I take the key out, put it back in and try again, I get no power at all. This happens once every few days.

Luckily I always carry a jump starter. If I hook the battery up to a jump starter, it starts right up every time. The battery is fully charged, purchased 3 months ago and is reading 12.6 volts at the terminal. Alternator was replaced in 2021 and seems good as well since battery has stayed fully charged during daily driving the past three months.

Showing no codes on my scanner. Any suggestions on how to resolve? Thanks!

 

[solli5pack]

Here's what supposed to happen when you turn the key.

When the ignition switch is placed in the START position, a discrete signal is supplied to the body control module (BCM) notifying it that the ignition is in the START position. The BCM then sends a serial data message to the engine control module (ECM) that crank has been requested. The ECM monitors the park/neutral position switch. If the transmission is in Park or Neutral, and there are no DTCs that inhibit engine starting, then the ECM supplies voltage to the control circuit of the STRTR relay. When this occurs, battery voltage is supplied through the STRTR relay to the X2–S terminal of the starter solenoid. The starter solenoid energizes, and supplies battery voltage to the starter from the X1–B terminal to crank the engine.


Verify that the battery is sufficiently charged and that the battery cables are clean and tight.

 

[j91z28d1]

sounds like a loose battery connection. like a loose cable being the most common and will act just like that.. you have power, hit it with the starter load, it pops( if you happen to be able to watch, you'll see an arc at night) and no connection. and then after jumping it, it's fine for a while.

you shouldn't be able to move the battery terminals at all by hand. if that's not it. check the other bolt on connection. follow the cables to the ground and starter. if everything is tight and clean.. replace cables.

you'll probably find a loose or corroded battery terminal or block ground.

 

[petethepug]

That pic is gorgeous as well as helpful. Cold weather = wiring shrinking or loss of continuity. You’ve already covered the battery and alternator so it’s pointing to the Achilles heel of these trucks …

Battery cable corrosion from inside out. Obviously the battery doesn’t charge itself on the 2nd or 3rd try turning over the ignition. It leaves the battery and the cables creating heat where there’s resistance (corrosion). Once that heat causes the cables to expand from the resistance, all’s fine again.

Do the ez, inexpensive thing next because those cables will also cause fake codes to appear on a scanner if they’re acting up.

 

[KraftMatic87]

Thanks for the input all! I just checked my battery and the negative cable is a bit loose around the terminal. Going to install a battery shim around the terminal to tighten it up and see if that eliminates the no-starts.

 

[swathdiver]

If I hook the battery up to a jump starter, it starts right up every time. The battery is fully charged, purchased 3 months ago and is reading 12.6 volts at the terminal.

What's the temperature outside when you take that voltage reading? If the drive time is during the day and long, does the alternator spend most of the time at full output, over 14 volts?

 

[KraftMatic87]

What's the temperature outside when you take that voltage reading? If the drive time is during the day and long, does the alternator spend most of the time at full output, over 14 volts?

View attachment 420747

My alternator is always running 14+ volts every time I check it while driving. Alternator seems to be doing its job. I’ve taken the voltage reading both when it’s below freezing and when it’s about 55-60 F outside and got the same reading both times.

 

[swathdiver]

My alternator is always running 14+ volts every time I check it while driving. Alternator seems to be doing its job. I’ve taken the voltage reading both when it’s below freezing and when it’s about 55-60 F outside and got the same reading both times.

Your battery is no good then. I know you said it's new but something is wrong with it. The alternator running at full output all the time tells us that the battery is not becoming fully charged.

I may be wrong if you are taking many short trips with the truck. In doing so, the alternator never gets the time it needs to fully recharge the battery. Take her out for an hour drive or more or put it on a battery tender.

With a bi-directional scan tool, you can see how the vehicle's computers see the condition of the battery and how it is charging it.

 

[KraftMatic87]

Your battery is no good then. I know you said it's new but something is wrong with it. The alternator running at full output all the time tells us that the battery is not becoming fully charged.

I may be wrong if you are taking many short trips with the truck. In doing so, the alternator never gets the time it needs to fully recharge the battery. Take her out for an hour drive or more or put it on a battery tender.

With a bi-directional scan tool, you can see how the vehicle's computers see the condition of the battery and how it is charging it.

I don’t think it’s at 14+ volts ALL the time on longer drives but when I hook up my battery to my trickle charger it says it’s fully charged after just 20 minutes on. If the battery was close to dead it would take almost a day or two to fully charge. We do a lot of short trips except on the weekends so I’m gonna install the shims to tighten up the negative battery cable and see if that makes the no-starts stop for now.

I have a fully charged spare battery in my garage I can swap out at any time if the one in my truck is toast for some reason. It’s an EverStart Platinum with 760 CCAs I bought new from Walmart and it replaced a DuraLast Gold battery that made it 5 years before needing replacement.

 

[swathdiver]

I don’t think it’s at 14+ volts ALL the time on longer drives but when I hook up my battery to my trickle charger it says it’s fully charged after just 20 minutes on. If the battery was close to dead it would take almost a day or two to fully charge. We do a lot of short trips except on the weekends so I’m guessing I’m gonna install the shims to tighten up the negative battery cable and see if that makes the no-starts stop for now.

I have a fully charged spare battery in my garage I can swap out at any time if that’s actually the case.

Use that temperature/voltage chart when checking your voltage in the morning after the truck has been sitting all night to see what its state of charge is.

While not common, we have seen intermittent problems like the one you are having caused by the post down inside the battery not being connected properly.

Well, you're on it and keep us posted.