2011 RAM 1500 Laramie w/ Hemi, 50K miles.

About 3K miles ago my idle started being unstable. Most of the time it idles okay at 650 in drive. However it has started dropping to 500 when I come to a stop and will occasionally stall.

I have cleaned the throttle body, run injector cleaner, changed plugs all to no change in symptoms.

When the idle drops to 500, it will return to normal (650) 25% of the time.

If I just touch the gas pedal the idle will go up to 650 and stay solid.

Is this the TPS? I've done the bench tests on it and it checks out fine.

Or could it be the sending unit attached to the gas pedal? This part I can not find anywhere. I can't find a reference to it, or a diagram. I've read about the ETC (Electronic Throttle Control) but it seems this might be the brain box and not the sending unit controlled by the gas pedal.

Any help in the area would be greatly appreciated.

Thanks.

 

500 is the normal RPM for the hemi with the AC off. The stalling though is unusual. How often does it stall and under what circumstances?

 

You make an interesting point. I've had the truck for just over a year and from the time I bought it, it has idled at 650, with or without A/C.

The only time it stalls is when stopping. When I stop the idle will either stay at 650 or drop to 500 and when it drops to 500 it either idles a bit rough or stalls.

The stalling was once or twice per trip. But I have become very conscious of it and as I mentioned before if I just touch the gas pedal the idle will go back to 650 and stay.

The 'touch' I'm referring to is just that a touch, I don't rev the motor.

It does this whether the A/C is on or off.

 

It could be a defective torque converter. I know a few years ago I had a bad torque converter, and my truck would do the same, i would stop at a red light and the rpm's would drop to 500 and the truck would stall. The only way i figured out it was the torque converter was from towing heavy, it would end up throwing a code on the truck for the dealership to read. After changing the torque converter it has never stalled.

But i do notice that from time to time the truck will idle at 500 at some lights but not stall, then all i do is tap the throttle same as you and it will idle at 650 like normal.

 

Things that make you go Hmmmm.... I just had the torque converter replaced under the Service Bulletin for the rattle and growling at 1700 RPM. I had read that some of the replacement torque converters while fixing this issue caused new issues.

Thanks for the tip. I'll investigate my torque converter and tranny codes.

Thanks again!

 

Also check out your fuel evaporation system for any kinks or leaks in the line. If you overfill your tank, top off, that can send fuel in the system and mess it up.

On another forum a couple of posters had a similar problem and found it was the fuel evaporation system.

 

Thanks to all that have responded. I have checked out all suggestions and haven't found a trouble or problem anywhere yet. The issue is getting worse. It is very prevalent when the A/C is off.

I changed the idle program to increase the idle by 150 rpm when the A/C is off and I can see the increase in idle speed when the A/C is off. But this hasn't prevented the problem from happening. The idle still drops to 450 - 500 rpm and if I just touch the gas pedal the idle will return to normal and stay there.

I'm trying to find the name and part number for the control unit that the gas pedal is connected to. With this vehicle being drive by wire and not mechanical linkage that the gas pedal control unit may be at fault.

If anyone knows the correct part number / name of it I appreciate your post with the info. Thanks.

 

Im having this exact issue with my 2011 Hemi as well
And I also used my tuner to dial up the idle a little higher to
stop it from stalling,, still dips down but 95% of the time pulls back up to idle.
Please post if you find a solution to this,
(Although I do suspect my torque converter to be the culprit)

 

One person on another forum had a similar issue and found the transmission fluid was low. Worth a check.

 

My other 1500 started having the same idle issue, it's a 2007 Sport 4x4 Hemi. This one was fixed by replacing the worn out battery. It wouldn't hold a charge.

As for my 2011 1500 Laramie, I just changed the tranny fluid and filters and checked the battery and charging system. All is fine in these departments, but it still drops in idle.

I have noticed that shifting to neutral brings the idle back up and then putting it back in drive the idle stays up. To me this seems to be a shift valve sticking not the torque converter because the pump is running in drive and neutral.

NOTE: For those having this issue, something to try. Manually downshift when coming to a stop and see if it still does it. Mine does not drop in idle if I manually downshift.

It seems that this issue with the idle is not caused by a 'single problem', but can be caused by any one of numerous problems.