Thread: M and S lights – replaced xyz switch and problem is back – other possible causes?

hey guys great feedback .,also have dreaded m an s problemo.,started up shifted to neutrel then stalled upon trying to restart engine turned fast but no start .,have a new large crank amp battery.,changed oil and thouroughly cleaned filter .,no oil in harness or ecu box ,.pulled xyz switch refurbed found to be in good clean order except small amount of oil seeped through gasket .,thoroughly cleaned all breathing pipe work and changed dirty filter and maf.,after reading these posts will check looms .,and starter solenoid .,do i need to clear faults to restart ?apreciate all who have taken time to help others here your feedback is both valuable and sometimes funny

I would check earth points and possible dirty connectors around the engine wiring.
I recently had intermittent fail to crank problems - turn the key - nothing.
After a few times of this happening I started to get the GB fail lights flashing. That sent me on search for gearbox problems, but the real issue was a dirty high resistance connection to the starter solenoid.
These ecu's can get very confused and send you off in all sorts of wrong directions.

Cheers,
Terry
2000 D2 TD5 auto

Gday all, first time poster here.
I have just started having the same problem with my D2 (im sure it has nothing to do with the fact that my wife has been driving it a lot lately!). The M&S lights flash after selecting reverse and the transmission goes into limp mode. I rang a land rover specialist and was told it would definately be the xyz switch. However after reading all your experiences i think i will definately start with the simple stuff my self.
Thanks

Greg

I've had the flashing M&S lights after start for a few weeks. They usually went away after restarting, but not always and occasionally they came on while I was driving along. The XYZ switch is only 6 months old. I checked the battery voltage with the Nanocom at around 11.8 - 11.9 V - the car still started with no problems. It showed around 14.4V with the engine running. Monitored it for a couple of days and found the battery wasn't charging. Replaced the battery today with a 1000CCA one from Caterpillar - no more M&S lights.

Also managed to kill my second battery - the Redarc wasn't seeing enough voltage on the start battery to connect the second battery (and I forgot to reset the isolation circuit breaker between the main and second battery for a few weeks.)

Conclusion -It seems that flashing M&S lights on start or the first gear selection (particularly reverse) are a good indication of a failing battery.

Greg what was the cause in the end?

Apparently a quick and simple test for the xyz switch is to put the windscreen wipers on
If you put your wipers on, then select reverse then the rear wiper should come on, of the xyz switch is working properly.
Not sure how valid a test it is, but something to consider
Best of luck.
Cheers
Muppet

Mines just started doing this after a situation yesterday where I was facing uphill, selected reverse then selected drive again to get into a parking space.
I cleaned the switch out several months ago and moved the air con drains and have had no problems until now.
I've just checked the battery and it's at 12.9v static and 14.1v charging at idle. Is that enough of a charge or would that cause a low voltage error - it always starts up quickly. If not then I suppose it's check the switch again and check the loom? I don't really wanna buy a new switch at the price they go for

Rich

I think the battery problem is related to the initial current demand when you first switch the ignition on.

The Td5 ECU alone will cause a 30amp 15V external power supply to dip below 6V for a fraction of a second when the ignition is switched and it's power supply capacitors charge up. Add to that EAT, ABS and SLABS ECU's plus the other loads and the battery will be faced with a very short spike in current demand that can pull the voltage of a weak battery below the error threshold for the EAT - 9.5V.

The problem is that a static reading won't pick this up, because once the ECU's have charged their power supply capacitors the load on the battery drops substantially and voltage returns to a more normal reading. The time frame for charging up the capacitors is well under a second from turning the ignition on.

You'd need to get the battery load tested to be 100% sure it's fine.

cheers
Paul