If it's intermittent, l'd remove and clean ground terminal at alternator bracket. A poor ground will cause charging issues and poor overall voltage/amperage conditions...which can lead to these issues.

 

To clear M&S lights you need to exit the car, close the door, lock and unlock. I agree that cleaning all your grounding points will help in this situation. I believe you can test your XYZ switch by seeing if the gears on your dash display reflect the gear that your selector is on.
I believe you can also turn on your wipers and switch into reverse, if the rear wiper does a single cycle then your XYZ switch is good. At least that will help you eliminate the switch from your troubleshooting.

 

Alrighty so reporting back and my dc voltage with the battery alone is 13DC and with the battery connected and turning the key on once it is still 13DC and with the car running it is 15DC.

 

I replaced the battery and alternator. Cleaned and re-tightened all the ground connections. My wipers did the cycle in reverse and my gear indicator showed the correct gear, except it was flashing. Nothing fixed the limp mode until I pulled the XYZ switch and cleaned and reinstalled it.

 

Those do seem reasonable, so low voltage shouldn't be causing the problem. I would still clean and tighten the connections to the battery, but I don't think that's going to be your primary area of focus. XYZ would be my next suspect.

 

Alrighty thanks, I'll definitely have to check into that. Ever since I bought it a while ago it always has this problem with the reverse not being precisely lined up when you put it into reverse and you almost have to wiggle it into reverse so I imagine that could contribute to the same problem possibly.

 

The XYZ switch has a couple milometers of rotational adjustment play in the mount. If you look at the cast case in the picture I posted of the switch housing, you can see the mounting holes are oval. When I first installed the switch it did not work. The gear indicator was just a tad off. I had to move the switch just a hair to get it lined up right. Once I got the fine adjustment set, it has not displayed the M & S lights or gone into limp mode again.

 

I had flashing m&s lights due to a bad CPS, but there were corresponding faults. My bad xyz switch, due to rust/corrosion caused no start.

I know, zero help, but that has been my experience.

 

There are 18 ''official'' reasons for flashing M&S warnings, 15 of them are together with limp mode, 2 with no apparent effect and 1 which will let it operate only in economy mode... low battery power and XYZ switch are the most common problem causing the flashing M&S lights. It's possible to be any of the many so the best is to read the stored fault code and if there isn’t one it usually means it's battery voltage (which yours sounds like it's good) or possibly old/low tranny oil related.

Other tips for flashing M&S lights… disconnect battery, leave for a few minutes, reconnect and leave ignition on for 5 minutes then restart and see if that works