Greetings from Norway!

You are all probably sick of these threads, but believe me, I have been through so many of them and tried so much now, and still can't figure out my M+S Flashing problem.

The car is a 1998 Disco II Td5

So a little prehistory to the fault:
When we bought the car the transmission was all good. It worked fine untill it had a steaming and anti-rust treatment underneath. When I drove it after this it worked for about 1 day, then all of a sudden it seemed like the transmission slipped after it had been parked in a hill, and after a mile or so the M+S started flashing. After this the fault comes pretty much right after startup, when the transmission shifts. The transmission have not seemed to slip ever after this.

Things that have been attempted since then:
Checked the battery and alternator. Gave the correct amount of voltage and seemed ok. The transmission oil (and filter etc) has been changed 2 or 3 times with no result. The car was delivered to a dealer who troubleshot it, supposedly checking all connections etc and could find no fault. They meant that the xyz-switch was good, and I've checked that it is properly adjusted, and it seems that it is. They concluded that the wire harness inside the gearbox could be the problem, as when this was wiggled the fault came and went. I am a bit suspicious to the extent they have checked the connectors for instance, as I've went over them myself and some of them seemed dirty and a bit loose. The gearbox was changed to an overhauled and reinforced one not too many miles before we bought the car.

I wonder though, can the battery hold the proper voltage but still be bad? For instance with a bad cell? Or could the xyz-switch be the coulprate even though it seems to be properly adjusted, for instance if there is moisture in it causing a short circuting? Any other tips for what to check?

Im really gratefull for any help I can recieve!

 

I'm thinking the steaming of the XYZ switch was the start of the problem, over here when water gets in there it starts with the symptoms you describe. You could try taking the switch out, taking the cover off, clean all the moisture and corrosion out, then reseal the cover with sealant, this has worked for many owners here. Or, you could replace the switch. Personally I'd try the cleaning first.

 

The XYZ switch has multiple contacts inside, and a steam cleaning may have heated up sludge that had previously been spread around evenly, it is now a puddle of slime in the bottom contacts. There are also electrical connectors just above the switch.

 

Pulled out the swich now and opened it, and it looked completely mint. Probably been changed at some point. So im out of ideas now..

 

I think the truck acting up is just a coincidence to the cleaning and treatment.
Pick up a used transmission computer and try that.
Those can be had for pretty cheap, it is under the left front seat.

 

I'm going to put it together tomorrow, and try a fresh battery first and see how that turns out. After that i will try to change the transmission computer. Does this have to be programmed to the car? Or is it plug and play?

 

It is plug and play, it will need to re-learn your driving habits but it will drive just fine.