Help me figure out how the +/- shifter buttons work please

milkmaster · August 12, 2021

First GM truck I have had in years. Somehow I can't quite figure out how the +/- buttons work on the column shifter. The manual refers to them being on the console shifter, but something isn't translating for me. I don't know what mode I must be in for them to work nor where on the dash I can read where it says what gear you are in besides "Drive? I must be misunderstanding the procedure. Neither +/- button does anything so far. My Ford worked anytime, but this truck has some sort of mystery to it. Can someone please kindly share the overview on how it works while leaving out the personal criticisms? Thank You!

Edited August 12, 2021 by milkmaster

OnTheReel · August 12, 2021

Need to drop the column shifter down to "low", they don't work in drive. Once there you'll get a readout on the DIC with current gear position. It's effectively a gear limit switch, won't go higher than what you select. It will also downshift one gear when you first shift to low and downshift more if you hit "-" and engine speed is safe to do so.

milkmaster · August 12, 2021

I think I may have found the answer. DOes the shifter have to be in the LOW mode? Can a driver do that without stopping first? Just a little afraid to yank it down to low when on the interstate and have it redline before I can stop it.

milkmaster · August 12, 2021

2 minutes ago, OnTheReel said:

Need to drop the column shifter down to "low", they don't work in drive. Once there you'll get a readout on the DIC with current gear position. It's effectively a gear limit switch, won't go higher than what you select. It will also downshift one gear when you first shift to low and downshift more if you hit "-" and engine speed is safe to do so.

Ok makes more sense now. My Ford didn't require you to change the shifter, I wasn't expecting that. My only time to possibly use it has been towing my trailer for the first time and see how it pulls a long grade without shifting all the time. Still learning the new truck.

JimCost2014 · August 12, 2021

52 minutes ago, milkmaster said:

I think I may have found the answer. DOes the shifter have to be in the LOW mode? Can a driver do that without stopping first? Just a little afraid to yank it down to low when on the interstate and have it redline before I can stop it.

Yes, and at speed it will go to the current gear. So, if you are traveling at 35 MPH, it should go to say 5 or 6 on the indicator.

It will downshift all the way to 1st at lower speeds, as I found out one day

OnTheReel · August 12, 2021

Eh, it’ll only downshift if/when the computer deems safe. It won’t blow itself to bits like the dummy who flat towed his Jeep in 4L.

CamGTP · August 12, 2021

I've had mine do 6th to 4th if I go into manual mode at 50+ mph. Which is fine but it does do the quick downshift.

Anacortes Army Guy · August 12, 2021

8 hours ago, milkmaster said:

Ok makes more sense now. My Ford didn't require you to change the shifter, I wasn't expecting that. My only time to possibly use it has been towing my trailer for the first time and see how it pulls a long grade without shifting all the time. Still learning the new truck.

When towing you should consider using "Tow/Haul Mode" as it will limit shifting in hilly terrain, even when in "Drive."

milkmaster · August 12, 2021

1 hour ago, Anacortes Army Guy said:

When towing you should consider using "Tow/Haul Mode" as it will limit shifting in hilly terrain, even when in "Drive."

Of course and thanks for the reminder! I consider that a given. At this point I was still just trying to figure out the operations of it all.

Edited August 12, 2021 by milkmaster

redwngr · August 12, 2021

The older OM's had a chart that showed which gear the trans would shift to when moved to low.

It depended on which gear it was currently in.

The write up indicates they still do this but I didn't find a chart in current manual (of course maybe I missed it)

Maybe the 'lower preset' also depends on which engine the transmission is connected to.

Manual Mode
Electronic Range Select (ERS)

Caution
Driving with the engine at a high rpm without upshifting while using Manual Mode, could damage the vehicle. Always
upshift when necessary while using Manual Mode.

Electronic Range Select (ERS), or Manual Mode, allows for the selection of the range of gear positions. Use this mode when
driving downhill or towing a trailer to limit the top gear and vehicle speed. The shift position indicator within the Driver
Information Center (DIC) will display a number next to the L indicating the highest available gear.

To enter Electronic Range Select or Manual Mode:

1. With the vehicle in D (Drive), pull back on the shift lever to activate L (Low). The L in the shift pattern will illuminate in red, and the D will switch to white.

2. Tap the left steering wheel control to reduce the highest gear available, or the right control to increase the highest gear available.

3. To exit, pull back on the shift lever a second time. The D in the shift pattern will illuminate in red, and the L will switch to white.

When shifting to L (Low), the transmission will shift to a preset lower gear range.

For this preset range, the highest gear available will be displayed next to the L in the DIC.

All gears below that number are available to use.

For example, when 4 (Fourth) is shown next to the L, 1 (First) through 4 (Fourth) gears are shifted automatically. To shift to 5 (Fifth) gear, tap the right steering wheel control or shift into D (Drive).

L (Low) will prevent shifting to a lower gear range if the engine speed is too high.

If the vehicle speed is not reduced within the time allowed, the lower gear range shift will not be completed.

Slow the vehicle, then tap the left steering wheel control to the desired lower gear range.

Cruise control can be used while in ERS.

Some transmissions