2006 x2 gauges not working

[mrm2083]

I know there have been many posts on this but I haven’t found a definitive answer. As some of you have seen in my restoration thread, I have been doing a major renovation to my boat and replaced the block (as well as a bunch of other engine components) and the entire dash with brand new gauges (all factory). All of my electronics were working perfectly fine but I just started having an issue with my gauges.

When I turn on the ignition they do the normal reset where it makes a noise and vibrates but then they don’t do anything. None of the analogue gauges are working, only the lcd screen in the RPM gauge. Also, the LCD screen is flashing “ECU”

Engine is running fine and all other electronics work. Battery is charged up and engine turns over quickly.

I noticed that other people have had the same issue but haven’t seen a definitive solution. I don’t want to buy a new MMDC to find out it’s the ECU, or vice versa. Or that the whole thing was a fuse.

Any ideas, I’m really stumped here.

[gwozhog]

The mmdc issue was worked out by 05 so I doubt that is your issue. Might want to check the plug wire connections on the MMDC and if you decide to get rid of those gauges please hit me up and I will make you an offer

[Flexx]

Give me your E-Mail adress, i will send you the Troubleshootings Guides for the Instruments and the MMDC.

[CruisinGA]

I’d start with contact cleaner on all gauge and MMDC connections

[rgardjr1]

I know there have been many posts on this but I haven’t found a definitive answer. As some of you have seen in my restoration thread, I have been doing a major renovation to my boat and replaced the block (as well as a bunch of other engine components) and the entire dash with brand new gauges (all factory). All of my electronics were working perfectly fine but I just started having an issue with my gauges.

When I turn on the ignition they do the normal reset where it makes a noise and vibrates but then they don’t do anything. None of the analogue gauges are working, only the lcd screen in the RPM gauge. Also, the LCD screen is flashing “ECU”

Engine is running fine and all other electronics work. Battery is charged up and engine turns over quickly.

I noticed that other people have had the same issue but haven’t seen a definitive solution. I don’t want to buy a new MMDC to find out it’s the ECU, or vice versa. Or that the whole thing was a fuse.

Any ideas, I’m really stumped here.

I have seen something very similar in my boat a few times over the years. I get the message BAD ECU and none of the gauges work expect the Perfect Pass. In my boat it's always an indication that my battery is low. I've always been able to solve this by plugging in my onboard charger and letting it recharge the batteries.

[Soder]

I have seen something very similar in my boat a few times over the years. I get the message BAD ECU and none of the gauges work expect the Perfect Pass. In my boat it's always an indication that my battery is low. I've always been able to solve this by plugging in my onboard charger and letting it recharge the batteries.

I experienced the same thing. My house battery was low and when I combined the batteries, BOOM, my gauges came back to life.

I charged the house battery that day while running on the lake and haven’t had the problem since.

[bcd]

Check the perko switch as well. Mine failed and caused my gauges to go dead. Putting it to both batteries would fix it.

Sent from my SM-G930V using Tapatalk

[mrm2083]

So I had a chance to check a few things and still haven’t found the issue. My battery is putting out over 12 volts and I am getting the same power at the terminals in front of the dash. I checked the voltage at the gauges and they are getting 6.9 volts. Boat starts fine and all of the electronics work fine except the gauges.

Would an ECU issue effect the battery and fuel gauges? If it wouldn’t then that would allow me to at least rule out the ECU (could still have its own issue but atleast I would know it’s unrelated).

[mrm2083]

Bump... any ideas on if the ECU would effect the gauges?

[Soder]

Bump... any ideas on if the ECU would effect the gauges?

My ECU is a MEFI 4b. Yours may be a MEFI 5 in which case I can't help you. See pictures.
If yours is a MEFI 4_, it doesn't report anything to the guages. The ECU reads some components that also are displayed on the dash but the ECU does not feed data to the MMDC. I'm 95% certain of this since MEFI 4_ does not read any fuel level.

If you really want to get into the nitty gritty, see the attached PDF.
Pages 5-8 & 5-9 show the J1 and J2 connector connections to the ECU.
These two connectors carry all "inputs" and "outputs" to and from the ECU. The only "output" to the instrument panel is the Check Engine signal (connection J1-27).

Gauges on my boat:
Oil Pressure - ECU monitors
Engine Temp - ECU monitors
RPM - ECU monitors
Perfect Pass - no connection to ECU
Battery Voltage - ECU monitors
Fuel Level - no connection to ECU

[mrm2083]

So I finally got it working. I want to post a recap to help someone who may have this dilemma in the future. It turned out to be the MMDC. I bought a used on on eBay and it worked. My issue was that my gauges would make the reset sound but wouldn’t move and the LCD at the tach would flash ECU. Power was above 12v to the MMDC and all gauges were at 7v. Once I plugged in the new one it worked perfectly!

[gwozhog]

Did the new mmdc change your hours on the hour meter?

[mrm2083]

Yes it did

[gwozhog]

Oh wow for some reason I always thought it was the engines computer that stored the hours. Do you by chance have the medallion part number?

[mrm2083]

Here is the one I bought. It was from an x45 but worked perfectly on my 06 x2