# Thread: How to Reset the Engine Hour counter on the oval Polaris MFD display

1. ## How to Reset the Engine Hour counter on the oval Polaris MFD display

Note: If you have the newer MFI display found on Virage and Genesis watercraft the reset method can be found in this thread.

This method is experimental (but seems to be working on each MFD display I have tried it with, so far). There are several unanswered questions regarding what exactly the various reset sequences (also known as CALibrate) actually do.

It has been documented for some time now how to 'reset' the MFD display to 'correct' an inaccurate voltage reading (LoPWR) on the MFD display. In my case I often ended up with a working but UNcalibrated voltage reading. For me, the result was typically that the MFD reads 1 to 2 volts HIGHER than the actual battery voltage. Until recently I had not done extensive experiments to determine why this was, or how to get a more accurate voltage reading on the display.

In the attached videos, the actual battery supply voltage was about 0.75 volts lower than the 13.9 that is displayed. Actual was just under 13.2 volts, measured with a Fluke 23 III.

Update: See this post. The MFD volt reading will only be accurate if the actual battery voltage is exactly 14.00 volts during the calibration.
If the battery voltage during calibration is less than 14.00 volts, the display will read high by the difference. In the example above, the actual voltage was 13.2 volts so the display read high by; 14.0 - 13.2=0.8 volts.

If the battery voltage is above 14.00 volts during calibration (such as when the engine is running) then the resulting voltage display will read LOW by the difference. If the charging system was providing 14.5 volts during calibration, the MFD will afterwards read 14.0 - 14.5 = - 0.5 volts (so the readings on the MFD would show 0.5 volts LESS THAN the actual voltage).

Note: This was initially tested on the oval MFD that I had on hand, from a 1997 Polaris Hurricane watercraft (model 3280224).

I have since successfully reset the Engine Hour counter and calibrated the voltage display on the following MFD part numbers;
3280252
3280202
3280147 (Round MFD)

I look forward to hearing from others who are willing to try this on their own oval or round MFD displays.

Note: This reset process does NOT apply to the Polaris MFI or NGI watercraft displays.

How to reset the Engine Hour counter on the Polaris oval MFD display
If display is sleeping (more than five minutes of no activity, engine not running) press the Mode button to wake it up.

Change display to show Engine Hours (use the Mode button)

With the HOUR counter visible, press and hold both SET and MODE buttons for several seconds
Display will show CAL 0000 ==> Promptly Release both buttons
followed by CAL 0828

Now press and hold SET button only
Display shows CAL 0828, then 0832, then 0828

Note: If tachometer is active (engine is running) then display shows CAL 0864, 0868

Continue holding Set button until clock reappears or MFD shuts down or reboots itself (about ten seconds)

Press Mode to wake up display
Wait until speedometer reading settles to zero
Press Mode several times until Engine Hour mode is displayed.
Should now show zero hours.

Tip: Press Mode to display battery voltage.
Use an accurate Multi-meter to measure the actual battery voltage at the battery posts and compare to the displayed reading.

Even better, touch the multi-meter probes directly to the Red/Purple and Black wires that feed the MFD display. These connections are inside the electrical box.
MFD Red/Purple wire is connected to one end of the 1/4 Amp glass fuse, all by itself.
For reference, here are the original Polaris instructions for the Oval MFD display.
Page 1

Page 2

2. ## Reset the Distance Counter (DIST) on Polaris Oval MFD display

Distance Counter reset (Miles traveled)

Use Mode button to cycle through until the display shows DIST

While DIST is displayed, press and hold SET button for 4 seconds, numbers should reset to 0.0

3. ## Change Polaris MFD display between Metric and US readings (Miles or Kilometers)

US/Metric mode change

Use Mode button to cycle through until the display shows VOLT

While in Volt mode, press and hold SET button for several seconds until m/h changes to km/h or back.

Both the Speedometer and the Distance traveled will change together, either Kilometers or Miles.

4. ## Polaris oval MFD entering 'sleep mode', then waking up from sleep mode

Sleep mode occurs at 3 seconds into video.

Note that the speedometer disappears and the clock appears automatically.

Also notice that under the clock all the mode labels are visible (RPM CLOCK DIST HOUR VOLT) when the display changes to sleep mode.

This may be an easy way to confirm when the MFD display is in fact sleeping; No speedometer digits visible and all mode labels visible.

Wake up occurs at 10 seconds in when tachometer signal activates (1200 RPM).

Note: This MFD was not installed in a watercraft so there were no signals connected for oil or fuel level. That is why the fuel and oil level indicators are not showing on each side of the LCD screen.

Related note: The terminal board in the electrical box uses a smaller 0.187" wide tab (only .020" thick) for the Red/Purple MFD wire. This is the board terminal with the 1/4 Amp glass fuse for the MFD.
The Red/Purple wire from the MFD has a matching smaller female connector that will only fit the fused terminal position. It will not fit on the wider tabs.

If you need to replace the female end on the MFD Red/Purple wire, it is McMaster-Carr 7243K112

All the other terminals on the terminal board are 1/4" (.250") wide tabs (.032" thick).

5. ## How to reset and calibrate MFD voltage display for ACCURATE voltage readings

After some investigation I determined that a specific voltage is required while resetting the MFD, otherwise the displayed voltage reading will be inaccurate.

The required voltage on Red/Purple during reset must be exactly 14.00 volts DC.

This is what I think is happening;
During reset calibration the MFD adjusts its internal voltage reference to exactly match the 14.00 volt reference voltage provided on the Red/Purple wire (pin 1 on the 8-pin connector). After the reset process has completed it will correctly display battery voltages from 10.1 up to 17.8 volts quite accurately only if during the calibration the battery voltage was exactly 14.00 volts.

This video shows a test of Polaris watercraft MFD (model 3280224) voltage display accuracy after CALibration was reset using a precise 14.00 volt DC power source during the calibration.

The resulting MFD voltage display appears to be fairly accurate (within 0.2 volts or better) as supply voltage (shown on the Fluke multi-meter) varies from 10.1 to 17.8 volts.

Surprisingly there is no over-voltage warning. Battery/charging system voltages above 17.8 volts will be shown as 17.8 on the MFD (1:35 in video).

LoPR display warning appears below 10.1 volts (0:40 seconds in video).

The question now becomes; How to generate an accurate and stable 14.00 volt reference voltage at the watercraft without using an expensive lab grade regulated DC power supply?

I have a few ideas but I am very much open to suggestions. I am looking for an inexpensive and easily obtained method that can be applied while the PWC is on the trailer or even in the water at dockside.

Update: A quick and dirty voltage calibration can be done in the watercraft with the engine running. Connect a multimeter to the battery, making sure the meter probes cannot vibrate loose.

Start the engine and bring the RPM up enough that the multimeter reads around 14 volts, assuming the battery is already well charged and the charging system is actually working.

While the engine is running and the battery voltage is hovering somewhere close to 14 volts, do the MFD voltage calibration sequence. When the MFD is finished calibration, you can shut the engine off.

The resulting MFD calibration will not be super accurate but it should be within a volt of correct, give or take.

6. I often suspected the same with the 14 volt thing. I would be fine with a unit that I could calibrate the voltage out of the ski. Funny how it shows low power below 10 volts. I have seen my MFDs show less than 10 volts.

7. ## MFD LoPR mode threshold testing, characterization

Originally Posted by BryanP
I often suspected the same with the 14 volt thing. I would be fine with a unit that I could calibrate the voltage out of the ski.

Funny how it shows low power below 10 volts. I have seen my MFDs show less than 10 volts.
This particular MFD (and I suspect other variants would be similar) does lots of funky stuff when the voltage sags below 10.9 volts.

During LoPR warning mode the display alternates every 4-5 seconds between the actual voltage reading and LoPR. So yes, you would be able to see voltage readings well below the LoPR threshold.

The documentation says the MFD can read down to five volts but this one goes unstable and continuously reboots below about 6.85 volts.

LoPR mode begins just under 10.9 volts. On this test unit the oil and fuel inputs are not connected. During LoPR mode the oil level lowest bar magically appears and stays visible, and the three lowest oil level bars fluctuate.

When the voltage next rises above the 10.9 level the display shows an OIL warning for a few seconds, and I have also seen it also warn for FUEL. My guess is that during LoPR mode there is some sort of internal cycle occurring which is a little bit unstable. When the voltage rises above 10.9 the MFD resets itself and rechecks everything, hence the transient oil and fuel warnings.

All this just reinforces how important a strong battery is to avoid voltage dips into the 'LoPR zone', especially during cranking. And cranking typically occurs just as the MFD is trying to wake itself up from sleep mode!

Here is the eye-wateringly boring video showing what this MFD does as the voltage is varied below and above the LoPR thresholds.

8. Originally Posted by BryanP
If he can reset MFDs to zero hours he will charge more for them on ebay
Well, I cannot do anything about that.

It was already known that these MFD could spontaneously reset themselves to zero hours. Now we just know how to do it on demand.

9. I did try the Hour reset procedure you described above on my 99 SLX, to no avail it would not enter calibration mode, could even get calibration mode normally. not sure the part number on that MFD, but SET and MODE both work. I will try on a few other MFDs I have

10. This is interesting, adjustable regulator to 14 volts, regardless of input....

http://www.batteryspace.com/dc-dcreg...14v05amax.aspx

Any idea of the amp draw from the CDI box on domestics? Is it possible that this can be used inline to maintain voltage above 10.6v to the CDI, even when cranking volts drop below....?? Curious.....