I bought my 2002 3500 drw used. It was from Canada with 12,000 miles on it. It has a sticker under the hood that says 3cyl cold start enabled. It sound pretty funny and idles high when it is cold out. Does anybody else have this or know anthing about it? ;D

 

Lots of discussion on this topic recently. Try a search on high idle enable. <br><br>You can also look at this tsb:<br>http://dodgeram.info/tsb/2001/18-019-01.htm

 

Thanks for the info.

 

Yes say thank you to the Sun Gods and whoever else as yours actually works and enjoy, if anybody at a dealer says he'll fix it for you seek ,search and destroy they are evil entities. PK

 

There has been alot of talk on this lately on another thread. I have it enabled on mine and it works well. Today for the first time i saw the 3 cyl. feature kick in and it seems to work well. The feature is there (Programmed in ECM) on most newer trucks and just needs to be enabled with the DRB at a dealership. A technician who understands the DRB can easily enable the feature,unless he's incompetent,which i understand has been the case a few times. If the feature is not already programmed in the ECM, it will have to be downloaded(Flashed) from the MDS(Mopar Diagnostic System) to the ECM. Then the feature will then need to be enabled through the DRB(Diagnostic Readout Box). This is how it works. After the wait to start light goes out,and you start the truck,the truck will idle for about 1 min. Then if the IAT sees 32 F and a coolant temp of 140 or less,will ramp the engine speed up to 1200 RPM. It will stay at 1200 Rpm until you either step on the brake,go pedal,or put into gear. If the IAT sees 15 deg. F or less and a coolant temp of 140 or less, will shut down 3 Cyl as it starts to ramp up to the 1200 RPM. Both features are intended to quicken warm up time as Cummins had problems with tar condensing on valves,and bending push rod tubes and valves due to the 24 V's cyl head running much cooler than the 12 V's. I have been using the feature now for a couple of month's and it works extremely well. It warms up the engine and cab faster than a block heater,and if you use the block heater will not allow the feature to work. This morning the ambient temp was 9 F and when i started the truck smoked like i have never seen before.After the 1 min. was up,the engine started to ramp,and then dropped off the three cyl's,and man did that sound weird. Well all i have to say is that after 10-15 min. my engine temp was well over the 140 mark and i was getting good cab heat.Touched the brake pedal and got back my 3 Cyl's and smooth idle. I know this was quite lengthy but i am impressed with the feature and figured disserved a decent explanation. ;D

 

How does killing three cylinders speed warm up? I am interested to hear how this can be better than a block heater. It's really important as cold as it is now!

 

it's not better than a block heater ...cold starts are hard on the engine <br><br>but when it's about 0 degrees outside the fast idle works fine even when the truck is plugged in .......<br><br>and yes dropping back to 3cyl does warm it up way quicker, why I don't know .......

 

By reverting 3 cylinders to a compressor mode it puts resistance on the engine and with only 3 other cylinders to run the engine generates more heat quicker.PK

 

I had the ECM upgraded at my dealer last Fall, and so far this winter have had the truck in temps below -20C (-5F). It is an excellent upgrade if you are in cold temps, and I highly recommend it. The dealer charged me 1/2 hr shop time to do the upgrade.

 

there has been a lot of discussion about this, so I am going to sticky this for a few days.

 

The only difference I notice when I plug in is that it must warm it enough that the grids don't come on. I don't get the wait to start light. Then it takes about three miles to get to 140 vs. four miles.

 

I have read a lot about this feature lately so I had to try it. I had the ECM reprogrammed last week at the dealer. Yesterday morning it was about -10C (up here in Canada eh!) and when I started my truck in the AM it idled for about a minute then gradually worked up to 1200 on the tach. Pretty neat! Nice and toasty inside after a cup of coffee in the house. Last night forecast lows of -18C so plugged in and the high idle feature did not activate this morning when I started up. So, I assume that the block heater makes enough heat to take it outside the parameters for activation. It also seems that teh block is able to retain heat for a long period of time as my truck sat in -13C weather for six hours and the feature did not activate when I started it this afternoon. I like the feature but would nice to have a little more generous parameters to activate the high idle. Just my .02 worth. Take Care

 

What does the dealer charge to flash the ECM??

 

Dave65 - my dealer flashed the ECM for no charge along with some other work I was having done. I have heard that some will charge a half-hour labour to do it.