I Have a 2010 Hero without EVIC. I can not seem to "zero out" or reset the MPG reading on the instrument cluster. I can zero out the trip odometers and the "run time" reading but the MPG stays the same. I have had 2 other Grand Caravans (2003 & 2007) and have been able to zero the MPG reading on those. Is this function no longer available, or do I have a defective unit? I think Chrysler really missed the boat here by putting the buttons behind the steering wheel. I do a lot of highway driving and like to keep tabs on the MPG, but every now and then, the missus likes to know what the temp is outside and it is a real pain to get to the button to change the reading. Thanks for your help!

 

Welcome to DF
Hope this is what you were looking for,This is out of the 2010 manual.

VACUUM-FLUORESCENT DISPLAYS
The Vacuum-Fluorescent Display (VFD) units are soldered to the EMIC electronic circuit board. Both the standard odometer and gear selector indicator VFD unit and the optional Compass Mini Trip Computer (CMTC) VFD unit are fixed segment dot matrix displays. The optional Electronic Vehicle Information Center (EVIC) VFD unit is a reconfigurable dot matrix display. With the ignition switch in the OFF or ACCESSORY positions, all VFD displays are deactivated. The total odometer information is displayed when the driver door is opened (Rental Car Mode) and is deactivated when the driver door is closed or after five minutes, whichever occurs first. Otherwise, all VFD units are active when the ignition switch is in the ON or START positions, and inactive when the ignition switch is in the OFF or ACCESSORY positions.

The illumination intensity of the VFD units is controlled by the EMIC circuitry based upon electronic dimming level messages received over the CAN data bus indicating the exterior lighting is turned ON and the dimming level selected using the panel dimmer function of the thumbwheel on the headlamp switch. The illumination intensity of the EMIC VFD units is synchronized with that of other display units in the vehicle by sending the same electronic dimming level message inputs to all electronic modules in the vehicle over the CAN or LIN data bus.

The odometer VFD unit has several display capabilities including odometer, trip odometer A and B, the cruise indicator, gear selector indicator, several textual warning or reminder indications, and various diagnostic information when certain fault conditions exist. The optional CMTC VFD unit displays compass, temperature, average fuel economy, distance to empty, elapsed time and cycles the optional park assist feature ON or OFF. The display options for these VFD units are selected using switches on the EMIC circuit board that are actuated using push buttons adjacent to the displays. The optional EVIC VFD unit displays several textual warning or reminder indications, compass, temperature, average fuel economy, distance to empty, elapsed time, audio settings and provides a customer programmable features interface. The EVIC display options are selected using steering wheel-mounted switches.

Actuating the odometer/trip odometer push button momentarily with the ignition switch in the ON position will toggle the odometer VFD between the odometer and trip odometer modes. Depressing the odometer/trip odometer push button for about two seconds while the VFD is in the trip odometer mode will reset the trip odometer value to zero. Holding the odometer/trip odometer push button depressed while turning the ignition switch from the OFF position to the ON position will initiate the instrument cluster self-test. The EMIC microprocessor remembers which odometer display mode is active when the ignition switch is turned to the OFF position, and returns the display to that mode when the ignition switch is turned ON again.

Actuating the right CMTC push button momentarily with the ignition switch in the ON position will toggle the CMTC VFD between the various display functions, and actuating the left CMTC push button toggles the display between standard and metric units. The EMIC microprocessor remembers which display mode is active when the ignition switch is turned to the OFF position, and returns the display to that mode when the ignition switch is turned ON again.

All EMIC VFD units are diagnosed using the instrument cluster self-test (Refer to 08 - Electrical/Instrument Cluster - Diagnosis and Testing) . Proper testing of the CAN or LIN data bus message inputs to the EMIC that control some of the VFD functions requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.



CLUSTER ILLUMINATION
The Dodge base EMIC has several Light Emitting Diode (LED) units that provide cluster back lighting whenever the exterior lighting is turned ON. The illumination intensity of these LED units is adjusted when the panel lamps dimmer function of the thumbwheel on the headlamp switch is rotated to one of six available minor detent positions. The EMIC monitors a hard wired multiplexed input received from the headlamp switch on the instrument panel to determine the selected lighting level. In response to that input, the EMIC electronic circuitry converts a fused 12-volt input it receives on a hard wired panel lamps dimmer switch signal circuit into a 12-volt Pulse Width Modulated (PWM) output.

The EMIC uses this PWM output to control the illumination intensity of the cluster general illumination lighting and the VFD units on the EMIC circuit board, then provides a synchronized PWM output on various hard wired fused panel lamps dimmer switch signal circuits to control and synchronize the illumination intensity of other incandescent illumination lamps in the vehicle. The EMIC also transmits electronic dimming level messages over the CAN and LIN data bus to other electronic modules in the vehicle to control and synchronize the illumination intensity of their display units to that of the EMIC displays.

The hard wired panel lamps dimmer outputs from the EMIC may be diagnosed using conventional diagnostic tools and procedures. However, proper testing of the PWM processing of the EMIC and the electronic dimming level messages received by the EMIC over the LIN data bus requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.

 

Thanks for posting this info, but it doesn't really answer my question. So with a lack of mention, I guess the function is not available. Thus my question then becomes what is the average fuel economy reading really telling me. Is it the average for the tank of gas, since tthe last engine start or the life of the car? I realize that this isn't a question for the forum, but one for Dodge/Chrysler.

 

I think this is what you are looking for
Reset?
Select your indicator to say the fuel econonomy
then press and hold it for about 5 to 10 secs it should still stay on the MPG selection and it should reset.
If it has never been reset, it is displaying your AVG from day1
It is a pain where it is located because I like to mess with it while driving too

 

Thanks, this is what I have been doing but it does not Zero out the reading. Say it is at 19.5 mpg and I press and hold at the gas pump, as I drive away through town the reading starts to drop 19.0 ... 18.5 ... 18.0 etc. I would think that it should reset to 0.0 and as I drive it builds up from there. This is how it worked on my 2007 and 2007 Grand Caravans. I am just interested to see if anyone else actually is able to reset to 0.0 MPG.

 

Ours does the same but you have to remember that the worst fuel economy you get is while idleing. It all works the same way. But having the reading start high is more realistic since you technically should never see 0 MPG with an engine running .

 

My issue with the high reading is a scenario like this: My MPG reading is 19.5. After filling at the pump, I push and hold the button for 10 seconds. My thought process says the MPG should now be 0.0. I have not gone anywhere, the engine has just been started so I have gone 0 miles so how can it say that I am getting 19.5 miles per gallon? If I stretch it, I can see your point - it is remembering what we started with before the fillup, but I question if that is really giving a actual 'from this point forward' reading. As long as you say that yours acts the same way, I will accept it as "that's the way it is" and move on. I appreciate your input and confirmation of your readings acting the same as mine.

Thanks

 

It won't reset to 0. That button the only thing will do is start the cycle again and start reading from the moment the cycle started.

 

If you reset it while you are parked shouldn't it read "0"?

 

That's what I thought, but it doesn't. It maintains the reading that was there before the reset.