Shifter notification

[DIESEL/VETTE]

2003 duramax, 160,000 miles
shut the truck off, went into store, came out, started truck, put in reverse and no reverse. Shift window displayed, range shift inhibited. Moved selector to neutral and then drive and back to reverse and everything is ok. No more notice. What does this mean. 1st. Time for this.

[DmaxMaverick]

It's been a while (a few years?) since I've heard this reported, but it sounds like an issue with the NSBU module. If yours is original, it is suspect. It's possible the problem was simply dirty or oxidized contacts, and it may not return any time soon. The original design module is black in color, while the updated design will be tan. The original design is typically only a (rare) problem during heavy snow driving, although they do fail like any component. This was all covered in depth in previous threads, but it's been a long time since it's come up.

[rapidoxidationman]

You'll also see that message if your engine is revved up or some other odd condition is present (rolling forward and trying to shift to reverse, etc.) when trying to shift. Self protection for the transmission.

[More Power]

You'll also see that message if your engine is revved up or some other odd condition is present (rolling forward and trying to shift to reverse, etc.) when trying to shift. Self protection for the transmission.

This reminds me.... In 1999 when GM sent a team of PR guys and engineers to Montana with a couple Duramax/Allison prototype trucks. During one of the first demo rides, one of the PR guys put the shift selector in reverse and then park while we were traveling about 20 mph. Putting the trans in reverse didn't do anything, but selecting park make a horrible ratcheting sound. In the end.... no damage though... that we could detect.

[DIESEL/VETTE]

Thank you for replys, i'm not goint to worry about it, truck runs great.