Idle goes down to 500 when stopped in Drive

[Robert Gil]

Is the check engine light on? Has it been on and off recently? Just because the check engine light is not on doesn't mean the PCM has not stored a 1-trip failure. If it has it could be a big clue to help in diagnosis.

If this is a torque converter issue, check to see if the Converter Clutch is operating normally.

When driving and coming to a complete stop, let the engine idle settle to the lowest rpm point. Once it's reached the lowest rpm, move the shifter to Neutral. Does the engine RPM flare higher than normal, say 1000-1500rpm?

Perform a test drive. Press the TOW/HAUL button so the tow/haul lamp illuminates in the instrument cluster. Start driving in a location so you can accelerate normally above 40mph. Under normal, light throttle application the torque converter clutch will apply in 3rd gear and the engine rpm will drop about 200-300 rpm.

See if it is operating like it should. This will help aid in your diagnostics.

I have an idle issue that the local Dodge dealer was not able top resolve. My truck runs excellent, but as soon as it warms up to running temperature and I come to a light or a stop on Drive and idle, the RPM's drop from about 650 to 500. The Dodge dealer replace the throttle body, Camshaft, Crankshaft, MAP Sensor, output and input tranny sensors, full tranny service, Accelerator pedal position sensor, and spark plug service. Also the transmission solenoid block module was replaced.

The truck runs great, just that drop when I come to a stop. If I turn the AC on, problem goes away, rpm's go back to normal. On reverse and Parking, rpm are perfect. Dodge dealer re-flashed the ECU and stated that the ECU has no problems. I do not have any engine codes and it is not stalling.

Has anyone encounter this issue?

 

[Robert Gil]

My 2007 Ram 1500 5.7 Hemi-when warm- at a stop light will decrease in rpm to about 500 or a little lower almost as though it is being strained by the tranny because when I put it in neutral it climbs right back up and when put back in drive it stays up. Only after I accelerate does it happen again... and when I put my foot on the brake and give it a little gas the problem also stops... thinking 02 sensor or torque converter... anyone?

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I have an idle issue that the local Dodge dealer was not able top resolve. My truck runs excellent, but as soon as it warms up to running temperature and I come to a light or a stop on Drive and idle, the RPM's drop from about 650 to 500. The Dodge dealer replace the throttle body, Camshaft, Crankshaft, MAP Sensor, output and input tranny sensors, full tranny service, Accelerator pedal position sensor, and spark plug service. Also the transmission solenoid block module was replaced.

The truck runs great, just that drop when I come to a stop. If I turn the AC on, problem goes away, rpm's go back to normal. On reverse and Parking, rpm are perfect. Dodge dealer re-flashed the ECU and stated that the ECU has no problems. I do not have any engine codes and it is not stalling.

Has anyone encounter this issue?

 

[PuffTheMagicDragon]

I have an idle issue that the local Dodge dealer was not able top resolve. My truck runs excellent, but as soon as it warms up to running temperature and I come to a light or a stop on Drive and idle, the RPM's drop from about 650 to 500. The Dodge dealer replace the throttle body, Camshaft, Crankshaft, MAP Sensor, output and input tranny sensors, full tranny service, Accelerator pedal position sensor, and spark plug service. Also the transmission solenoid block module was replaced.

The truck runs great, just that drop when I come to a stop. If I turn the AC on, problem goes away, rpm's go back to normal. On reverse and Parking, rpm are perfect. Dodge dealer re-flashed the ECU and stated that the ECU has no problems. I do not have any engine codes and it is not stalling.

Has anyone encounter this issue?

My two trucks are the same way. I’m fairly certain that is how the truck is supposed to run. It is just a lower idle rpm to save on gas or emissions or something once warmed up. Turning on the ac puts more strain on the belt and alternator so the computer bumps the idle rpm back up to compensate. If you notice, when the rpm drops at a stop, you can turn the wheel and the rpms jump back up. Or like you said, turning on the ac works too. The computer is programmed to recognize the extra load and put the rpms back up. If the truck doesn’t need those extra 150 rpms, then it drops to 500. It is programmed that way. Seems to be intentional and working as intended.

 

[Silver The Mega]

thats the way its supposed to operate guys... lay it to rest.

 

[jmd4100]

My two trucks are the same way. I’m fairly certain that is how the truck is supposed to run. It is just a lower idle rpm to save on gas or emissions or something once warmed up. Turning on the ac puts more strain on the belt and alternator so the computer bumps the idle rpm back up to compensate. If you notice, when the rpm drops at a stop, you can turn the wheel and the rpms jump back up. Or like you said, turning on the ac works too. The computer is programmed to recognize the extra load and put the rpms back up. If the truck doesn’t need those extra 150 rpms, then it drops to 500. It is programmed that way. Seems to be intentional and working as intended.

Makes sense, its just a little worrisome because oil pressure and voltage drops. As long as its supposed to...


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[billyboy0713]

My 2007 Ram 1500 5.7 Hemi-when warm- at a stop light will decrease in rpm to about 500 or a little lower almost as though it is being strained by the tranny because when I put it in neutral it climbs right back up and when put back in drive it stays up. Only after I accelerate does it happen again... and when I put my foot on the brake and give it a little gas the problem also stops... thinking 02 sensor or torque converter... anyone?

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Did u ever figure this out

 

[RamDiver]

Did u ever figure this out

This thread is 6 years old, and the member you're quoting hasn't been seen in just over 5 years.

If you require assistance, please provide the fault description, including the history and mileage.




And, welcome to Ram Forum.

.

 

[MrBonez]

Did u ever figure this out

My 2008 does it too and with all the previous it seems to be the norm.

In my case all I do is hold the brake, very lightly "Tap" the gas and it goes up to about 650 and stays there until the next time I have to stop - I guess if you turn the wheel or something, that will make it pull the engine down a little more so it goes up to where it really needs to be (Need to try it myself one day).
Either way it looks like it's coded into the way they are setup to run and while I don't like it because of it being a potential contributor to any possible future hemi-tick issues, I can deal with it.