Hey guys, thanks in advance,

So I asked the same question on forum today, but the "minor solution" of buying a new battery did not work...

Car was cranking but wouldn't start. After fourth go it did start. Went next time I tried it. But then didn't after that. Got it going again and when I was driving it went into limp mode and the S and M lights came on.

Checked battery, was at 12.3v so figured that might be the problem... bought new battery, took for test drive and limp mode came on about 10km in.

Just went out to try to test the battery with engine running to see if it was alternator and after turning ignition on the S and M lights started flashing and I cannot even start the car to test it! New battery is sitting at 12.83v with car off and I tested the harnesses as well as terminals so the connection is ok.

From what people have said it could be: alternator, XYZ or crank position sensor.

I can get hold of a reader but don't have one on me, any ideas of what I should do next or what the S and M lights coming on and preventing me from starting the car mean?

Cheers,

Matt

 

Can you detail your vehicle make and model for us in your signature?

Your issue sounds similar to mine further down this forum but I haven't yet had limp mode happen while actually driving.

 

Hey mate, sorry yeah I have added that info (I think)

Truck is 2003 Disco 2 V8

 

There are multiple reasons that the M+S lights flash. You should try to read the transmission codes to point you in the right direction. Not sure Autozone or another chain can read those for you. That light can flash if the transmission control module is not getting proper voltage as an example as well as XYZ switch issues.

I had a similar issue as you described, got the codes read and it was a low voltage issue. I had voltage drop from bad grounds so cleaned up all the grounds I could reach in the engine bay and problem solved.

 

Thanks for response, yeah I guess at this point all roads lead to getting the codes read! Cheers, Matt

 

Hey zski, I am trying to work out where the grounds are, from what I can find Googling it seems the starting, charging and ECU grounds are the most likely culprits... but the RAVE is beyond my comprehension... is there an easy way of describing where I could find those? Thanks!

 

There is a page in the RAVE that shows all the grounds on the D2. Some of the quick ones to get to are the battery negative terminal which I think you checked since you got a new battery, following the negative cable there is a spot on the chassis right near the fuse box. There is another on the engine below the alternator next to the black coolant pipes.

still get the codes read so you can narrow down the cause.

 

Thank you, will give those a go!