Transmission dropped to neutral

[Jim Hainsworth]

I was out this last week on some trails and after the truck was jump started( left a door ajar during a bird hunt). As I was heading out the transmission just dropped to neutral. I was in 4hi and the shifter was still in drive but nothing. Shifted to park and back, and tried to put in to 2hi but nothing would work. Shut off and restarted and it went into drive just fine. I am just wondering what might have caused this? The roads were dirt but were not overly loose, I was wondering if there was any sensor that could detect a binding in the transfer case.

[akrockhound]

There is a service bulletin to replace one of the electronic components of the transfer case.

In my case it shifted to 4WL while I was parked and the service engine light came on. At the dealer they found the codes and it lead them to the service bulletin.

You might see if you have any codes or have your dealer look into the service bulletin.

Mine is an '03 2500HD Duramax/Allison

[DmaxMaverick]

Welcome to the Forums, Jim!

I don't think I would attribute this to any more than your battery situation. Low voltage has a way creating all kinds of havoc. I doubt any harm was done, as the systems are pretty well protected. These systems have proven to be very reliable, even when things go bad.

Usually when you have an issue that seems to be "fixed" with a restart, there was some confusion with the logic (the truck's...not yours). A restart forces the PCM to re-evaluate previous errors and faults. If the condition isn't repeated, the PCM gives the go-ahead for normal operation. Even if your SES lamp is no longer illuminated, there should be a stored code which will tell what was going on at the time. If the condition can't be repeated, the code(s) will remain in memory for a specific period, ignition cycles or warm up cycles, depending on the class of trouble code. If the problem goes away, you should have no worries.