I recently purchased (by private sale) a 2003 Disco HSE.. This rig ran great for a week and then... Jekyll and Hyde. Here's the rundown.

At first, some "stuttering" like misfires going on.. put it seemed sporadic. Then, accompanying these "stutters", the "S and M" (lol) warning lights on the dash would flash, and the vehicle would become very sluggish, not shifting, etc... SO after reading a few articles on here, it seemed reasonable to think that somewhere between the plugs, wires, and or coil packs, therein would lie the problem.. So, I changed the plugs myself, that didn't seem to help.. I brought it to a local garage that I have friends at, and they did the plug wires, and coil packs. According to them, when they hooked it up to the electronics with some kind of device they have, they were reading misfires in cylinders 4 and 7, and some other ones that were dealer specific.. Anyhow, after changing the the plug wires and the coil packs, the vehicle still runs like crap, however, their computer says only misfire on cylinder 3 now, plus other dealer specific codes.. After reading the manual, I can see that the flashing S and M lights denote a fault in the transmission, is it possible that misfires cause that? Any ideas on whrere to go from here would be greatly appreciated. Thanks!

 

No, misfires will not cause the M&S lights.
The M&S lights can be caused by a dead battery or alternator. Have your battery and alternator checked out. Also check all battery and alternator cables and make sure they are properly fastened at all ends, also check the earth straps.
Have your coolant tested for combustion gasses - your friends at the garage will know what to do.

 

Can you get us a list of all the codes?
If your battery/alternator checks out, I'm voting for Crank Sensor.

 

A bad crank position sensor is not going to cause those problems, or throw error codes for that matter.

 

Mine did. M and S lights, tranny in limp home 3rd gear, and it threw codes, the most telling code was for the crank sensor. It ran a little rough, though not enough to throw misfire codes. And of course, it stalled when hot, and wouldn't restart.

 

Get your battery and alternator tested before you do anything else to rule that out as a possibility....start simple and work your way up. Below ~13A will put the truck in limp mode.

 

Hey folks, thank you for the responses.. After leaving my mechanics place today, the m and S lights flashed, So like before, I pulled over, turned off the key (This had in the past reset that condition until the next stutter) then restarted, unlike before, they didn't reset themselves, and after trying to drive, it got progressively more sluggish.. So I did the unthinkable, I parked it, called triple A and had it towed to the Rover dealership in Scarborough, Maine... I know, I know.. but frustration drives people to do funny things.. After I got dropped off at home, and had a stiff drink, I got a call about 2 hours later from Rover.. The service manager tells me that the plug wires that were installed by my mechanic (Recommended by Napa) are arcing all over the place.. SO tomorrow morning, they'll replace those with OEM ones.. 300.00 and go from there.. I asked him if the arcing wires had anything to do with the tensmission fault, he says probably not, it could be some kind of Park switch? Park reset switch? I forget what he said, but something like that.. Anyhow, I will commit myself to reading everything I can from the fine posters here, and see if I can learn something in the process.. Oh.. and the codes were.. P0003, P0004, P0007 then two codes that had no number but a 3 letter designation something like DLC or similar with a contact your dealer after them.. I didn't read them myself, but that's what was relayed from my mechanic. Thanks gain for your ideas and info, I'll keep you guys posted!

 

Hi Jafir, oddly enough, the engine has never stalled, no matter how rough it's running, and odder still, it idles pretty good, Wish I could drive it in idle mode lol...

 

Then it's probably not crank sensor. Those m and s lights flash because the transmission computer detected something wrong. Hopefully the dealer finds it to be something simple.

 

STOP THROWING MONEY AT YOUR PROBLEMS AND READ UP SOME MORE ON THIS SITE BEFORE DOING ANYTHING ELSE! YOU'RE KILLING ME SHELLING OUT ALL THIS CASH!

Have them use 8mm wires if you're getting them done again (nevermind...the dealer won't do that)

Have they tested your battery/alternator yet? I'll bet you a shiny new nickel that's the reason you're getting the M+S lights.