GMC Sierra RPM Rising when Shifting gears Down

MarkL1 · 10-28-2005, 04:09 PM

My 2005 Sierra 1500 Pickup's (automatic) RPMs increases as the truck shifts from second gear to first gear. It does this on its own. As I put on the break or not put on the break and the truck slows down when it shifts into first the rpm rises around 400 RPM just like I was reving it up. The dealer is now saying that this is normal operation for this vehicel. I have never had a vehicle do this before. Does anyone else's vehicle do this and has anyone had success with someone repairing the vehicle. I believe it is electronic issue. Thanks very much for any help anyone can offer.

Itstali25 · 10-29-2005, 12:49 PM

Hey Mark can't say i know about your problem, but i just wanted to say welcome to the forums and come by as much as ya want! I'm sure someone on here can help ya out, we have alot of smart people on here.

chevyguy · 10-29-2005, 11:25 PM

I am confused , exactly what is it doing, I think by reading the thread it idles at 400 rpm and revs higher between gears? Is this right?

MarkL1 · 10-30-2005, 06:49 AM

Yes. I have an automatic. As I put on the break and as the truck shifts down from 2nd gear to 1st gear the rpm rises 500 rpm by itself. It sort of spikes up then comes back down. It does not stay there at that higher rpm, just spikes up then comes back down to its idle RPM in first gear. Does this make sense?

chevyguy · 10-30-2005, 09:06 AM

So it spikes to 500 RPMs, or adds 500 to whatever it is currently at? i need to know how high it is getting, not just a how much it increased. please post totals. There are some transmission disengage points programmed into the newer trucks to allow easier shifts and extend transmission life. But I dont have enough info to verify this with your truck yet.

MarkL1 · 10-30-2005, 11:06 AM

Thanks for your help. I will try it and get all the exact specifics on the RPMs. Right now I am not sure of the exact rpms and the like. I will try again tomorrow and get back with you. Thank you very much for the help.
Mark

chevyguy · 10-30-2005, 12:08 PM

I will help in any way that I can. Good luck

97SierraStepSde · 11-19-2006, 08:48 PM

It sounds like its normal, but depending on how high it rises and if its you putting it in 1st gear while down shifting or if its just the computer doing it. But I have a 97 Sierra, and with normal driving coming to a stop light it automatically down shifts and my RPMs rise maybe 300 with just normal computered downshifting. I hope this helps, but I dont know if its higher on the newer trucks.

STPETEBLUE · 12-05-2006, 06:24 PM

Sounds like a normal downshift to me.

10-28-2005, 04:09 PM	#1
MarkL1 Junior Member Join Date: Oct 2005 Posts: 3	GMC Sierra RPM Rising when Shifting gears Down My 2005 Sierra 1500 Pickup's (automatic) RPMs increases as the truck shifts from second gear to first gear. It does this on its own. As I put on the break or not put on the break and the truck slows down when it shifts into first the rpm rises around 400 RPM just like I was reving it up. The dealer is now saying that this is normal operation for this vehicel. I have never had a vehicle do this before. Does anyone else's vehicle do this and has anyone had success with someone repairing the vehicle. I believe it is electronic issue. Thanks very much for any help anyone can offer.

10-29-2005, 12:49 PM	#2
Itstali25 Senior Member Join Date: Jul 2004 Location: Southern Missouri Posts: 708	Hey Mark can't say i know about your problem, but i just wanted to say welcome to the forums and come by as much as ya want! I'm sure someone on here can help ya out, we have alot of smart people on here. __________________ http://www.cardomain.com/ride/644045 Trucks are just cars when they grow up!!! If your gunna get a truck....Get a TRUCK!!

10-29-2005, 11:25 PM	#3
chevyguy Senior Member Join Date: Sep 2005 Location: ALABAMA Posts: 3,555	I am confused , exactly what is it doing, I think by reading the thread it idles at 400 rpm and revs higher between gears? Is this right? __________________ Some people are like slinkies, Basically useless, But fun to watch when you push them down the stairs.

10-30-2005, 06:49 AM	#4
MarkL1 Junior Member Join Date: Oct 2005 Posts: 3	RPM Question Yes. I have an automatic. As I put on the break and as the truck shifts down from 2nd gear to 1st gear the rpm rises 500 rpm by itself. It sort of spikes up then comes back down. It does not stay there at that higher rpm, just spikes up then comes back down to its idle RPM in first gear. Does this make sense?

10-30-2005, 09:06 AM	#5
chevyguy Senior Member Join Date: Sep 2005 Location: ALABAMA Posts: 3,555	So it spikes to 500 RPMs, or adds 500 to whatever it is currently at? i need to know how high it is getting, not just a how much it increased. please post totals. There are some transmission disengage points programmed into the newer trucks to allow easier shifts and extend transmission life. But I dont have enough info to verify this with your truck yet. __________________ Some people are like slinkies, Basically useless, But fun to watch when you push them down the stairs.

10-30-2005, 11:06 AM	#6
MarkL1 Junior Member Join Date: Oct 2005 Posts: 3	I will try it and get more specifics Thanks for your help. I will try it and get all the exact specifics on the RPMs. Right now I am not sure of the exact rpms and the like. I will try again tomorrow and get back with you. Thank you very much for the help. Mark

10-30-2005, 12:08 PM	#7
chevyguy Senior Member Join Date: Sep 2005 Location: ALABAMA Posts: 3,555	I will help in any way that I can. Good luck __________________ Some people are like slinkies, Basically useless, But fun to watch when you push them down the stairs.

11-19-2006, 08:48 PM	#8
97SierraStepSde Senior Member Join Date: Nov 2006 Posts: 106	It sounds like its normal, but depending on how high it rises and if its you putting it in 1st gear while down shifting or if its just the computer doing it. But I have a 97 Sierra, and with normal driving coming to a stop light it automatically down shifts and my RPMs rise maybe 300 with just normal computered downshifting. I hope this helps, but I dont know if its higher on the newer trucks.

12-05-2006, 06:24 PM	#9
STPETEBLUE Full Member Join Date: Oct 2006 Location: St. Petersburg, FL and Waycross, GA Posts: 34	Sounds like a normal downshift to me. __________________ 2005 Silverado 3500 DRW 6.6L LLY/Ally 5 Spd \| LT \| EC \| LB\| '06 Silverado "Steel Bed" Tail Lights, '06 Towing Mirrors, VR Straps. Click here for more about The Florida Diesel Truck Club

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