I changed the oil on my 6.7 when it had 15,533mi and reset the oil change warning light. Now it has 19,699 and the "oil change required" warning comes on again. That's only 4,166mi since I changed it. Everytime this warning comes on, do I just change the oil again or ignore it till I drive it a little longer? Thanks!

 

The 6.7L learns how you drive and turns on the oil change light according to your driving habits. The computer adjusts the oil change intervals based on your driving.....

OPERATION
The change oil indicator gives an indication to the vehicle operator when a duty-cycle algorithm contained within the software of the Powertrain Control Module (PCM) determines that a recommended oil change interval has been attained. This indicator is controlled by the instrument cluster logic circuit based upon cluster programming and electronic messages received over the Controller Area Network (CAN) data bus from the PCM.

The change oil indicator function of the odometer Vacuum Fluorescent Display (VFD) unit is completely controlled by the instrument cluster logic circuit, and that logic will only allow this indicator to operate when the instrument cluster receives a battery current input on the fused ignition switch output (run-start) circuit. Therefore, the odometer VFD change oil indication will always be OFF when the ignition switch is in any position except ON or START. The instrument cluster will turn ON the change oil indicator for the following reasons:

Change Oil Indicator Lamp-On Message - Each time the ignition switch is turned to the ON position and the cluster receives an electronic change oil indicator lamp-ON message from the PCM indicating that a duty-cycle based recommended oil change interval has been attained, the change oil indicator will be illuminated for about three seconds, until the trip odometer reset switch button is depressed, or until the ignition switch is turned to the OFF position, whichever occurs first.
Change Oil Indicator Reset Procedure - Once an engine oil change has been completed, the PCM duty cycle counters can be reset using the following procedure. Turn the ignition switch to the ON position, but DO NOT start the engine. Slowly depress and release the accelerator pedal fully three times within ten seconds. Turn the ignition switch to the OFF position. If the change oil indicator illuminates the next time the engine is started, repeat this procedure.
The PCM continually monitors numerous sensor inputs to determine the duty-cycles to which the engine is being subjected. A pre-programmed algorithm within the PCM then determines when to send the proper lamp-ON or lamp-OFF message to the instrument cluster, also known as the Cab Compartment Node (CCN).

 

So the computer thinks you need an oil change based on a mathmatical forumula. It looks at how you're driving, populates the fields of the formula, and bingo... change oil light. It does not actually analyze your oil. I've often heard people think the computer is smoking crack.

It's your vehicle, you make the call.

 

The computer will also trigger the "Change oil" light if it calculates, by the RPM and regen cycles, that the calculated percentage of diesel fuel in the oil has exceeded 5%. I would consider having an oil analysis done, and would also check the oil level (at least 30 minutes after running) to see if the level is over full possibly indicating diesel fuel contamination.

 

my dealer forgot to reset the light after the oil change (and at 25/ quart plus fee that was one expensive service.. so i am pretty miffed)... anyways they are 45 min away and i dont want to waste teh time or the fuel to get there..

we didnt discover it till a week after we got home (never heard the chime)... and now its been 2500 miles since the old change (we figured it was your basic every 5000 miles chime not based on driving etc)...

anyways - is it still ok to reset it now as the prev post instructs? or will that mess up the computer for the next oil change.. or should i just leave it till the next change (and of course tell the service people off.)

ml

 

I would still reset it. The thing will activate back on if you need an oil change again. After I do my oil and reset it, it only gives me around 4600 to 5200mi then the indicator chimes again. Once it does, I redo my oil change again. If I were you, I would do the oil change myself. You will save half the money that the dealer charges you or a little more, and do a better job than they do. It's easy!! All you buy is the genuine mopar oil filter at the dealer parts and buy 3 gallons of oil of your choice. I use mobil delvac 1300. It's a good oil.