Owners of certain examples of the 2024 GMC Sierra HD truck have reported an issue where the headlamps flash and/or the windshield wipers pause while wiping. If you find this inconvenience to be occurring with your Sierra heavy-duty pickup, here may be why.
According to a writeup on GM TechLink, the Body Control Module (BCM) communicates with the Lighting Control Module (LCM) via the Controller Area Network (CAN) bus in order to operate the headlamps and wipers. If an affected truck’s battery dips below the threshold in the LCM during a cranking event, or if the battery has been discharged and needs a jump start, the Lighting Control Module may go into a reset every eight to ten seconds, which causes the headlamps to flash.
This all makes the voltage diagnostics in the Lighting Control Module fail, which in turn throws the P0606 Diagnostic Trouble Code (DTC). From there, the best path moving forward is to test the battery following the recommended testing procedures in the appropriate Service Information, and then replace the battery as necessary. Alternatively, simply disconnecting the battery will reset the LCM.
As a reminder, the 2024 GMC Sierra HD is offered with two powerplant options, including the standard naturally aspirated 6.6L V8 L8T gasoline engine, rated at 401 horsepower and 464 pound-feet of torque, and the optional 6.6L V8 L5P turbodiesel Duramax engine, which has been uprated for the mid-cycle refresh to 470 horsepower and 975 pound-feet of torque.
Notably, both engine choices are mated to the Allison-branded 10-speed automatic transmission.
Under the body panels, the Sierra HD rides on a more capable variant of the GM T1 platform – which it shares with its corporate platform-mate, the 2024 Chevy Silverado HD. Production takes place at the GM Flint plant in Michigan.
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Comments
What was wrong with a standard switch to turn on the headlights and wipers? You know the kind that never has a problem. What advantage is there running this thru a computer? If it ain’t broke don’t fix it. Head scratcher?
The hits keep coming, these are 2024 model they shouldn’t have low voltage . Technology is getting in the way of making dependable vehicles not to mention the crazy prices
Spend $75-$100k on a new GM truck delivered with clearly defective components. Pretty Average.
exactly what is needed on a lonely darken highway east of Omaha. Thanks, GM.
I knew that sounded familiar.
Here I am, on the road again!
Bob Seger
….turn the page.
It is ridiculous how complicated vehicles have become. The sad part is that it is unnecessary. Car accessories ran fine with 12vdc power, fuses, and switches. I’m just not sure that we need a computer, relays, and circuit breakers to turn on the headlights!
“The Body Control Module (BCM) communicates with the Lighting Control Module (LCM) via the Controller Area Network (CAN) bus in order to operate the headlamps and wipers.”
Even Rube Goldberg is shaking his head.
Why can’t the light switch directly turn on the lights, and the wiper switch directly turn on the wipers? The way things used to work?? Versus kicking off a series of events though multiple modules, which may or may not have the intended effect at the end…
After loosing dealerships with the GM bankruptcy, remaining dealers wanted a reliable income stream. Thus the Mandatory Service Scheme was bred and born.
Junk gm always wanting a update on computer on my 3.o diesel its alway in for emissions problems too
Soon we will be calling the geek squad to fix our rolling software.