Flashing M and S lights
 

Went outside today, got ready to drive to work and I was greeted with the dreaded limp mode lights.

Vehicle is a 2003 Disco with 92k miles. Checked the battery with engine off and holding at 12.6 volts. With engine running, AC on and light on 14.2 volts. About 3k miles ago I serviced the transmission, new filter and fluid. Also when I shift into drive I keep a flashing indication near the shifter. No check engine light during this whole ordeal.

Next plan of action is to get under the truck and check the XYZ switch connector for corrosion clean it up and hope that makes a difference.

Haven't hooked up the scanner but I was wondering if I'm going to get a code even though the check engine light isn't on?

Hoping that I might get some helpful advice on what else I might look into.

The tranny codes are another range of numbers. You may need an advanced or dealer scanner to read all of them. The XYZ can get full of muck from several things, including AC condensate drain. Some have removed, drilled out, cleaned up, resealed.

Thanks Savannah, although don't like the fact my cheapo code reader isn't going to do the job.

Besides the XYZ is it possible that crankshaft sensor has something to do with this as well?

No, the CKP controls when plugs fire, and when misbehaving it usually stutters when hot, then stops, works again when cold. Finally just does not work. Test is check for sparks when acting up.

Here's the D2 tranny codes and when they turn on the lights, etc. I think that if you have no CEL (but do have sport/manual or M&S light) that it points at low battery volts, see attached chart. That could be a fudged connector under the console at the tranny CPU. The tranny monitors battery volts. Having this happen when starting is logical, big amp draw from starter will show up things like dirty battery terminals, corrosion on the big wires in front of the underhood fuse box, corroded frame ground (follow negative battery cable).

The battery itself may not be dropping to 9 volts, but down stream just past a high resistance connection the volts will be dropping.

Your code reader may be able to display the geneic OBDII codes for the trany, but some, like P1884 have additional info only a more advanced scanner can talk with.

check all your grounds along with the battery, a corroded ground will also cause M&S

More great info guys. I'm going to spend a little time under the truck tomorrow checking grounds and doing a little connector cleaning. I'll report back with the results. Thanks.

Just a little update.

Cleaned and inspected all ground connections....a little surface rust but nothing major.

Cleaned and inspected the XYZ connection. This had more corrosion and road grime on it than expected.

Just for ****s and jiggles I replaced the battery. 74 dollars of peace of mind.

In the end not sure what the magic ingredient was (probably a little of all three) but the truck starts better than it ever did.

Thanks everyone!

hope you sealed that xyz up good with some new silicone on that gasket.

Sorry for jumping on this thread but I'm having the exact same problem. I purchased a 2003 Disco about 4 months ago and my M/S lights started flashing. I took it to the dealer but before then I took it to a local mechanic for a quick check up. He checked the voltage and told me the battery was ok. He recommended I go to the dealer and sent me on my way. As I was driving I noticed the service light turned off and never turned back on during my 10 mile drive (When it usually turns on after driving about 2-3 miles). They charged me for cleaning and sealing the battery cables because the car had no codes. They said it was probably the corrosion on the positive cable. Flashing stopped for about 2 days but then started back up. Before the lights start to flash the tranny jolts hard and the service light flutters for a few seconds. Then a minute later the car goes into limp mode and service light comes back on. A few questions:

Could it mean something if the lights start flashing after car has warmed up?

Also when the local mechanic checked the battery voltage it somehow fixed the problem long enough for the dealer not to be able to read the codes. Could the little charge been able to fix the problem?

I'm not very good with engines so this may seem like a stupid question. How and where can I find the XYZ cables to be able to clean them?

Note: Today I purchased a new battery so it can't be the battery.

did you have the alternator checked as well? hoping you did wouldn't want to kill a new battery.

the xyz bolts to the driver side of the transmission. download the RAVE manual so you can learn more about your vehicle and how it operates.