Onstar advanced diagnostic alert and Range AFM

[ShamrockShooter]

So I just got a text and and email from Onstar saying an issue with my engine or transmission was detected in my 2016 silverado and I should bring it to the dealer within 1 day. It has been driving normal and I don't have any warnings or check engine lights on the dash.

 

I do have the Range AFM plugged in. Could this be blocking Onstar so it thinks there must be a problem?

 

Anyone ever get one of these messages from Onstar?

 

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[ShamrockShooter]

Also I looked and the 21st of the month is when Onstar always sends me the diagnostic report, so this probably isn't anything to do with that.

 

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[Sierra706]

Haven't gotten any of those and my range has been plugged in for 6 months

 

 

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[ShamrockShooter]

Well I guess it could just be a fluke as I havnt had any other issues with range either. Or there could be something wrong and Onstar is smart enough to figure it out before a check engine light comes on

 

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[ShamrockShooter]

Turns out my check engine light was on! I followed the instructions on the Range website and it cleared the dash light.

 

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[Ozer]

Hows the gas mileage with the Range? Any drops or increases?

[ShamrockShooter]

Hows the gas mileage with the Range? Any drops or increases?

It really depends on the type of driving. I would say between 1 to 2 mpg. But over a year that's like $100 in gas. It is totally worth the extra cash for how smooth the trucks drives always in v8

 

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[dorkweed]

Hows the gas mileage with the Range? Any drops or increases?

 

 

I've been using the Range essentially since I bought my truck almost 1 year ago. It always seems that I'm bucking a headwind or quartering into a headwind on my I-road travels. However; on the times where I've had light winds or a slight tailwind, On those times, I've averaged between 20-22mpg. Best has been 22.4mpg running 70mph thru Wisconsin.............not exactly flat. Bucking the wind.........about 17mpg running 70mph.

[Sierra 5.3]

 

 

I've been using the Range essentially since I bought my truck almost 1 year ago. It always seems that I'm bucking a headwind or quartering into a headwind on my I-road travels. However; on the times where I've had light winds or a slight tailwind, On those times, I've averaged between 20-22mpg. Best has been 22.4mpg running 70mph thru Wisconsin.............not exactly flat. Bucking the wind.........about 17mpg running 70mph.

Can't you just unplug it whenever? So unplug it on highway and plug it in for city?

[JimCost2014]

So I just got a text and and email from Onstar saying an issue with my engine or transmission was detected in my 2016 silverado and I should bring it to the dealer within 1 day. It has been driving normal and I don't have any warnings or check engine lights on the dash.

 

I do have the Range AFM plugged in. Could this be blocking Onstar so it thinks there must be a problem?

 

Anyone ever get one of these messages from Onstar?

 

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Yes the Range will block the report, or at least it used too. If anything is plugged in the OBD port it messes with the OnStar communications with the truck.

[ShamrockShooter]

Yes the Range will block the report, or at least it used too. If anything is plugged in the OBD port it messes with the OnStar communications with the truck.

In this case Onstar worked great and reported the error code caused by the Range. I still get the monthly report even with the Range plugged in.

 

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[ShamrockShooter]

Can't you just unplug it whenever? So unplug it on highway and plug it in for city?

You can unplug it whenever you want just it's preferred to do it with the vehicle off.

 

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[Sierra706]

Around town i didn't notice too much of a drop, as I would ride it more aggressively or in manual to keep it from dropping 4 cylinders. I'll notice a 1-2 drop on a long highway trip. But I don't make those often, and the sound of 4 cylinders irritates me with my exhaust so I leave it plugged in. Leveling/lifting cost me about 1mpg on the highway. Aggressive tires 3-4mpg town and highway.

 

 

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[Sierra 5.3]

Around town i didn't notice too much of a drop, as I would ride it more aggressively or in manual to keep it from dropping 4 cylinders. I'll notice a 1-2 drop on a long highway trip. But I don't make those often, and the sound of 4 cylinders irritates me with my exhaust so I leave it plugged in. Leveling/lifting cost me about 1mpg on the highway. Aggressive tires 3-4mpg town and highway.

 

 

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So you have taken about a 6mpg hit do to modifying? so like 14-15mpg hwy?

[dorkweed]

Can't you just unplug it whenever? So unplug it on highway and plug it in for city?

 

 

I don't want my truck going into V-4 mode.............EVER!!!!!!!!