2008 Yukon Denali - Dash Lights resetting Electrical Issues

[ratified442]

New to me 2008 Yukon Denali with 110K. Every morning (especially on cold mornings or damp morning) truck runs and start normal but dash cluster resets and radio skips (sound from radio is suspended for a split second and the screen quickly blinks). No other issues other than the transmission seems to not shift consistently. Some days perfect and other days jerky. Usually this issues continues for the first 5 minutes of driving.

So - after much searching - replaced ALL the battery cables and mega fuse but did not replace the line going to the alternator. Battery is a Deka and was replaced not long ago. Volt gauge moves around a lot but always within range. Battery terminals are clean

Dealer - claims they cleaned the grounds but suspected that the issue was not resolved - they were right. I "believe" they reset the BCM but service manager was not 100% sure.

Runs and drives great otherwise and no other electrical issues. I'm planning a magnacharger in the near future but want to resolve this issue first! Thank you for any help.

 

[GM Customer Service]

Hello ratified442,

I am sorry to hear that you are experiencing some issue with your vehicle. I might not be able to provide you any technical support and I cannot guarantee anything but I would be happy to look into this concern for you. Please private message me referencing this thread if I can be of any assistance.

Jennifer T.
GM Customer Care

 

[ratified442]

Did it again today but after 30 min of driving. Rained last night - thought for sure it would happen again when I first started it but it didn't.

Any ideas out there? Anyone ever have an issue with the deka brand battery?

 

[08grey]

It's probably a ground behind the dash.

 

[ratified442]

I haven't looked under the dash yet - any ideas where I should start? Is there is a known issue with the ground under the dash? Any other grounds i should check? Thanks

 

[08grey]

Not any I know of. But the steel back there is know to rust for no good reason and may be the issue.

 

[ratified442]

Looked under the dash didn't see anything obvious or rusted. Still looking for ideas. Thanks

 

[ratified442]

No ideas out there? I also just installed the blue fuzion handsfree and noticed it made the situation worse once initially installed and then stopped. Wondering if the radio is making the dash reset? Maybe a bad ground in or around the nav unit? Help.........

 

[08grey]

If I were you I would pull everything up and start wiggling connections one by one until I get it to repeat itself. Luckily the dash and components are pretty easy to pull.

 

[scottg918514]

As far as the jumpy voltmeter. Mine is the same and it appears to be normal. From some GM service manual (not sure where):

Battery Sulfation Mode
The BCM will enter this mode when the interpreted generator output voltage is less than 13.2 volts for 45 minutes. When this condition exists
the BCM will enter Charge Mode for 2-3 minutes. The BCM will then determine which mode to enter depending on voltage requirements.

Charge Mode
The BCM will enter Charge Mode when ever one of the following conditions are met.
• The wipers are ON for more than 3 seconds.
• The GMLAN Climate Control Voltage Boost Mode Request is true, as sensed by the HVAC control head. High speed cooling fan,
rear defogger and HVAC high speed blower operation can cause the BCM to enter the Charge Mode.
• The estimated battery temperature is less than 0°C (32°F).
• Battery state of charge is less than 80 percent.
• Vehicle speed is greater than 145 km/h (90 mph)
• Current sensor fault exists
• System voltage was determined to be below 12.56 volts
• Tow/Haul mode is enabled
When any one of these conditions is met, the system will set targeted generator output voltage to a charging voltage between 13.9-15.5 volts,
depending on the battery state of charge and estimated battery temperature.

Fuel Economy Mode
The BCM will enter Fuel Economy Mode when the ambient air temperature is at least 0°C (32°F) but less than or equal to 80°C (176°F), the
calculated battery current is less than 15 amps and greater than -8 amps, and the battery state of charge (SOC) is greater than or equal to 80
percent. Its targeted generator output voltage is the open circuit voltage of the battery and can be between 12.5-13.1 volts. The BCM will exit
this mode and enter Charge Mode when any of the conditions described above are present.

Headlamp Mode
The BCM will enter Headlamp Mode when the headlamps are ON. Voltage will be regulated between 13.9-14.5 volts

Start Up Mode
When the engine is started the BCM sets a targeted generator output voltage of 14.3 volts for 30 seconds.
Voltage Reduction Mode

The BCM will enter Voltage Reduction Mode when the calculated battery temperature is above 0°C (32°F). The calculated battery current is
less than 1 amp and greater than -7 amps, and the generator field duty cycle is less than 99 percent. Its targeted generator output voltage is 13
volts. The BCM will exit this mode once the criteria are met for Charge Mode.