Basically last week my Disco 2 died in the middle of the street while trying to park.

The alternator was going bad and the battery was weak so it just cut out on me. I got the M&S blinking lights at the end just before the truck cut out.

I have replaced the alternator and its working fine however I am still getting the Blinking lights, I have NO forward motion on the truck - no of the forward gears work, only R works and I am getting a P0722 code. The lights on the shifter move to the right position when I move the shifter but they blink along with the M&S lights

Where do I start ? I am going to drain the tranny fluid as the truck has 140k on it and I dont think the previous owner ever changed it.

THanks

 

Oh and if it helps at all I dont feel the tranny engage when I put it in to drive. When I put it in R i feel it connect, is it possible something else is wrong ?

 

The same thing happened to me only my D was blinking. I had the battery tested and it needed replaced when I did so it all stopped flashing. Not sure if this is a fix for you but you may want to test your battery.

 

yep, test battery

 

Tranny has electronics and does not like low battery, can even make codes for it and flash those lights. Clean up all battery cables while replacing battery. Battery life 3 years usually. Good idea to do tranny fluid AND filter (more involved - read up on it).

 

The battery should be good - its only a few months old, but I will check again

 

If my battery is showing 12v is there anything else to check as far as the battery is concerned ?

The Black cable looks to be in pretty poor shape

 

1. You need a good meter. Battery, when truck is at idle, with no extra things turned on, should be reading 13.8 - 14.2 volts. A really high volts, like 14.8 or better, usually means regulator in alternator has failed "closed" and we are now overcharging the battery, and some electronics may be damaged.

A voltage lower than 13.6 is pretty weak, and usually means that alternator has lost one or more diodes inside it. It may still put out volts, but as you switch on things, like lights, AC, fan, the volts can drop below what is required to charge the battery. Then you drive around charging, then discharging, over and over, and eventually the discharge wins, and battery is too weak to crank truck, or run important things like the transmission computer.

So, if at idle the battery reads 13.9 volts, great. Now switch on the AC and the fan and the head lights. If it is still above 13.4 great. If it is down in the 12's, alternator can't keep up with the load.

Now let's test the battery - turn off truck, with nothing on. Read volts. Let's say it reads 12.9. Turn on head lights. It should drop a little, but if it goes to like 11.0, 10.5, 9.3 - your battery has a "dead cell" and can't ever carry enough load. You'll need a new one.

You can also have all sorts of issues with dirty connections. The big ones on the battery, the end of the negative cable where it bolts to the frame, and the large wires inside the underhood fuse box. All should be extra clean, tigh, and free of corrosion. The dirty connections increase the "voltage drop" by adding a lot of resistance. The more power that goes through that point, the higher the drop. So you can have a good alternator and new fully charged battery, and a bad wire connection can deliver 8 volts to something on the truck and it won't work like it should.

The transmission has its own ECU, which has cables, and the tranny has a cable that goes inside it (possible connector water leak) and a switch on the side (XYZ switch) that tells the computer which way you want to go.