Mini Maxx issue?

Strokersace · Jun 7, 2018

Not sure what I have going on with my Mini Maxx.

Bought it used on here a year or 2 ago. Been installed with custom tuning since November of 2017 and around 10,000 miles since complete engine build.

I did not try to update this unit when I got it. Just put MCC custom tunes on it and rocked out!

Driving a few weeks back, I got to where I was going and noticed my gauges on the MM were "stuck" and not adjusting (egt was still showing 650 at idle). Shut truck off, attended the meeting, truck started back up fine, but noticed when I got on the highway, I had a roaring "freight train" noise at speed. Sounded like the engine was reving much higher than what it actually was. Pulled off and as I was slowing down I noticed the gauges on the MM were frozen again. Check engine light came on briefly as I was slowing.

Once stopped, I tried pulling codes on the Mini and it was locked up. Couldn't adjust tunes, access menu, nothing. Shut truck off and it would not restart. Dead in water. I checked the key on power, fuses, everything. After fiddling with the obd-II plug, I was able to get the Mini Maxx to reconnect and pulled codes and cleared codes. Codes were:

U0073 - Control module communication Bus A off
U0115 - Lost communication with ECM/PCM "B"
U0155 - Lost communication with instrument panel

After clearing them, truck started up fine. Gauges all read fine. Got back on highway about 1 mile later the freight train noise came back and Mini Maxx froze. You guessed it, Rinse and Repeat! This time when I got everything going enough to clear codes, I unhooked the Mini Maxx from the HDMI able complete. Had ZERO issues the rest of the way home and over the next week of driving it.

Then the other day, sitting in my driveway, I plugged the Mini back in. As soon as id start the truck, the Mini would work correctly for maybe 5 seconds, then freeze. Truck wouldn't restart. Tried same tricks I did before and no luck. Used my other code reader to check and clear codes. Same exact codes as before. So I left the Mini unplugged and in the console. Truck seems to be running fine with no issues so long as the MM is unhooked. The only time I had the CEL was when it flashed that 1st time.

What the heck could be going on with it?

I really like having my gauges! And the ability to shift between tunes.

sootie · Jun 7, 2018

Could try a different HDMI cable. Sounds like can bus signals are getting screwed up.

Strokersace · Jun 8, 2018

sootie said:
Could try a different HDMI cable. Sounds like can bus signals are getting screwed up.

Yep, tried that too. No change.

The only time I can get the Mini Maxx to load up and not be frozen is if I "1/2" insert the plug on the obd-II port. Can scroll through menu but as soon as I fully plug it in, it freezes and locks up.

sootie · Jun 8, 2018

Interesting. Back in the day I remember an H&s tech walking someone thru the exact problem you are describing. I wish I could find it...

He also said to only plug it in far enough to get power and then do something else. Darn.

Strokersace · Jun 8, 2018

sootie said:
Interesting. Back in the day I remember an H&s tech walking someone thru the exact problem you are describing. I wish I could find it...

He also said to only plug it in far enough to get power and then do something else. Darn.

If you come acrossed it, please let me

I tried a different HDMI cable last night just to have the law of averages. I was hoping for something miraculous, but I was let down. I don't want to try to update it because of all of the things that I've read about updating the older models and them not working after that.

The one thing that I just thought about it but haven't tried is to partially plug it into the port so that I can at least get into the menu, and see if I can uninstall it and then reinstall. I may try that tonight.

If I cannot find a resolution, I may have to break down and buy another one.

sootie · Jun 8, 2018

do NOT update it.

Getting into the menu wont prove anything because the unit is not communicating with the truck, it is simply powering up.

Strokersace · Jun 8, 2018

sootie said:
Getting into the menu wont prove anything because the unit is not communicating with the truck, it is simply powering up.

Shoot, you're right. Because as soon as you plugntnin fully it communicates and then freezes.

Strokersace · Jun 10, 2018

Bump. Any other ideas?

Strokersace · Jun 23, 2018

Jacked with it some last night. I can getting to the menu during the initialize communication message even when fully plugged in. But as soon as I go to the general main screen it freezes each and every time.

I'm completely at a loss.

Looks like I'll be buying another Mini Maxx and dealing with getting the custom tunes on it.

Which brings up another question... Right now it's set and stuck on the highest power setting. If I have to get a new unit, will this become my base or stock file? Will it possible any problems? Would I need the ECM reflashed?

sootie · Jun 23, 2018

If you get another H&S, it will overwrite whatever is on the truck currently. Those units do not save a "stock" flash. When you return to stock, it loads a generic Ford flash from the SD card. Short answer-no need for a Ford reflash.

Strokersace · Jun 23, 2018

sootie said:
If you get another H&S, it will overwrite whatever is on the truck currently. Those units do not save a "stock" flash. When you return to stock, it loads a generic Ford flash from the SD card. Short answer-no need for a Ford reflash.

When you say, "return to stock", are you referring to the replacement unit? Or on the one I have now? If the latter, I tried returning to stock last night. It would begin the process but part way through when it tells you to have key on engine off, it doesn't give the prompt on the unit to continue. Tried it twice and got stuck in the same spot both times. Had to abort by unplugging from the OBD2 port.

sootie · Jun 23, 2018

Strokersace said:
When you say, "return to stock", are you referring to the replacement unit? Or on the one I have now? If the latter, I tried returning to stock last night. It would begin the process but part way through when it tells you to have key on engine off, it doesn't give the prompt on the unit to continue. Tried it twice and got stuck in the same spot both times. Had to abort by unplugging from the OBD2 port.

I'm speaking in general. Leave the truck the way it is so at least you can drive it. Don't risk bricking the pcm.

Luke@MillerPerformance · Jun 23, 2018

I’ve seen lots of issues with the OBD port itself. The pins get loose and cause all sorts of issues with the device plugged in. You can get a replacement OBD pigtail from Ford with a better pin fit.

Strokersace · Jun 26, 2018

Would it be advantageous to try one of these before I go down the rabbit hole of getting an entire new unit or replace an OBD2 port pigtail?

https://www.strictlydiesel.com/p-2356-hs-repl-obd-adapter-block-709916.aspx

Strokersace · Jul 9, 2018

Update on this.

Went ahead and ordered a new one from Mike at No Limit. Got everything installed on Saturday and it’s working like a champ!

Feels good to have it back.

bigrpowr · Jul 9, 2018

Strokersace said:
Update on this.

Went ahead and ordered a new one from Mike at No Limit. Got everything installed on Saturday and it’s working like a champ!

Feels good to have it back.

glad you're all better brother.