Chevy Avalanche Fan Club Forum

Avalanche Owners Zone => Chevrolet Avalanche Problems, Questions & Answers => Problems: Drivetrain & Steering => Topic started by: tommckay on 06/30/18 09:31 AM

Title: Help with drivetrain issue
Post by: tommckay on 06/30/18 09:31 AM
I tried searching for this issue and couldn't find anything exactly matching my problem. At least I dont think so....

My issue happened to me this morning. I was running on the freeway and I got a service 4wd on the DIC and the speedometer started dropping even though I wasn't slowing down. Then as it dropped it stopped driving the wheels, like it was in neutral.  Once slowed down to about 20mph, it will kick back in and I can reestablish speed... until it happens again.

I also have a problem with the speedometer being inaccurate.  It will say 58-59mph when I'm doing 77mph according to my GPS.

I'm also having problems with the speed control randomly accelerating beyond my set point. Set it at 75mph, and it will run up above 80 and want to keep going.

Any thoughts on this would be appreciated.
Title: Re: Help with drivetrain issue
Post by: MS03 2500 on 06/30/18 09:59 AM
I would go to auto parts store and have the codes read.
Title: Re: Help with drivetrain issue
Post by: tommckay on 07/01/18 05:22 AM
Another question for those smarter than I.

I bought a Range device to do the DOD disable, but as soon as I plugged it in and started the truck, it made my fuel gauge and oil pressure gauge fluctuate dramatically and I saw the service 4wd on the DIC. I immediately shut it off and unplugged the unit. When I restarted it all seemed normal again.
But then the above happened with she service 4wd issue.
Title: Re: Help with drivetrain issue
Post by: redheadedrod on 07/01/18 07:37 AM
It is always best if you can post what year your truck is...

Also did the issues happen before you used the range device?

If not the first thing I would do is disconnect the battery for an hour or so and reconnect. Then do NOT reuse that Range device as you likely have a defective device. Very common with "clone" devices with other types of devices so I wouldn't be surprised if it is the case here too.

Title: Re: Help with drivetrain issue
Post by: tommckay on 07/01/18 06:24 PM
Yep...   I have a 2007 LT with 80,400 on the odometer.  That could help. sorry.

I bought the Range device directly from the Range technology website, so I would think it wouldn't be a clone.

the issue never happened before I tried the range device, but I took off on a trip and it started at a point further than I had ever driven it at one time before so I really don't know.

I will be writing Range Technologies to tell them what happened and see what their response is.
Title: Re: Help with drivetrain issue
Post by: redheadedrod on 07/02/18 05:59 AM
I would certainly pull the negative battery terminal and let it sit for at least an hour and reconnect to see if your issues fix themselves.

And definitely contact the manufacturer. Expect they will try to deny they caused your issues and don't offer up possible excuses.

Your truck didn't do that before you added their device and now it does.

Do you have to leave it plugged in for it to work or do you program something with it and unplug it when its done?

Title: Re: Help with drivetrain issue
Post by: Vaeagleav on 07/02/18 07:11 AM
From reading older threads about the Range AFM device the way I remember it, they install the device under the dash and leave it plugged in to stop AFM. There was one or two people who found out over time that there was a parasitic drain of power if left parked and caused issues. I believe they removed the Range and drain went away.
Title: Re: Help with drivetrain issue
Post by: tommckay on 07/02/18 06:55 PM
It has instructions on the Range AFM disabler stating to unplug it if your going to leave your vehicle sit for more than a few days due to battery drain. You just plug it in to the OBD2 port and leave it there
 When you take it out your truck returns to AFM (DOD)

I contacted Range Technologies and their customer service was good. They are sending me a new one they will test and certify. And pay the return postage on the old one.

When I return home from vacation, I will do the battery disconnect and look for any blown fuses.