Thread: Causes and Solutions - Flashing M&S Lights

Apologise if the question is a stupid one but have you checked the fluid level correctly? That is with the engine running?

Must be the month for M and S lights... I have a V8 Disco 2 that has all of a sudden started to do the following.
When you start the car it is all good, accelerates up to about 2800 rpm before the box clunks into limp mode (holds 1st until this happens). M and S come on and car is locked in 3rd or 4th. Upon restart goes off and car seems back to normal. Drives forward and reverse, torque converter stall test passes, clean oil in sump and no fragments/metal on magnet. When driving it is just locked in 1st but wont bring lights on until you get to the 2800 rpm mark again.
In low range, instead of going to limp mode, it just brings the lights on past that rpm and holds 1st. There is no MIL light, only M and S.
I know I need to hook into it and find codes but was just wondering if anyone had experienced these symptoms. Seems very strange that it just won't change from 1st being an electronic auto.
I suspected it was the battery being low because it has been a bit sluggish, but surely the battery would not prevent it from changing gears??

Does anyone in the western part of Victoria (Warrnambool/Hamilton) have a Nanocom or similar that can help me out? Or someone willing to post me one to borrow. Don't really want to buy one just yet as I may be up for an auto rebuild shortly.....Would be a hell of a lot easier with a reader!

Sure ,with assistance,engine warmed up R.N.D.3.2.1...

any similar experience on injection malfunctions? or throttling, which triggers M+S?

Hi Massoud

As sierrafery says you really need to plug in an electronic diagnostic unit and see what fault codes are reporting from the transmission. I may stand corrected but the transmission is obd2 compliant so the error codes will be prefexed with a P.

Alternatively if you don't have the tools, sub it out to an automatic transmission specialist. The zf transmission fitted is common to a large number of makes and models so I would expect some one in your part of the world will have experience with them.

Cheers

Steve

HI, undortunately the transmission ECU is not completely OBDII covered, most of the more common faults are not so the best is to read it with dedicated tester cos a generic OBDII might misslead

Originally Posted by NANOCOM GUIDE; BOSCH AUTO BOX GS8.87.0 - System Overview

Manufactured by Bosch, this ECU appears to compliment the Motronic M5.2.1 Engine
management system. Not being Flash Programmable, there are two near identical systems sub
numbered .0 and .1 with the main difference between the two being different shift points,
different Gear lever switch inputs, and current gear indicator outputs. This version was fitted to
all Automatic versions of the Discovery series II. It is an adaptive unit, which means that it
learns and stores the driving habits of the owner and adapts to suit their driving style as well as
overcome variations in engine power, etc which can be reset with this module. This ECU does
support some OBDII compliant fault codes as well as a large number of codes outside of the
standard which this module accesses.

as i detached connector ,there were some Oil in it .
i washed visible surfaces hoping it did not penetrate ECU itself!

was this reported before? should i dismantle ECU's cast and inspect inside of it?

Had issue with M&S lights after changing motor (V8).
Diagnostic computer couldn't read the body computer (charged $88 for privilege).
Cleaned body and engine computer connector plugs and sockets with contact cleaner as advised by tech and all was good.
James