Not starting and flashing m and s lights

[Timlandy113]

Hi everyone, from some research the flashing m and s lights have been discussed in many forums but I couldn’t find one with the not starting issue too. Over the last month or so my 1999 Land Rover v8 petrol has not wanted to start once warmed up. Happens intermittently (usually in an awkward spot like the gas station), I sit in the car for 10-30mins and it will go eventually. I have tried disconnecting and reconnecting the battery but that doesn’t fix it. There’s no click or other noise when trying to start and all the dash lights come on as usual so not a flat battery. This happened again yesterday but it fired up after sitting there for approx 20 mins. Driving to work this morning I had the m and s lights flashing and the D for drive flashing too. Wondering if anyone else has had this issue and if the great minds in here think the two things will be related. Cheers, Tim

[shack]

Have you scanned for faults?

Either way I'd be checking the XYZ switch.

The BCU will prevent the car from cranking if the gearshift isn't in Park or neutral, or if the XYZ switch says it's not in those gears even if it is.

A faulty XYZ switch will also cause the M&S lights to flash and either the incorrect gear to be displayed on the dash, or for the dash gear indicator to blink.

Try starting in neutral by moving the shifter to neutral BEFORE turning the key on, then see if it will go.

If it is the XYZ switch, the auto will also go into limp mode and prevent 1st, 2nd and most likely 4th gear from being used, it will also prevent converter clutch lockup.

So limp mode should only be used to "limp home", if the M&S lights aren't flashing, it should be ok to use.

Cheers

[Timlandy113]

Have you scanned for faults?

Either way I'd be checking the XYZ switch.

The BCU will prevent the car from cranking if the gearshift isn't in Park or neutral, or if the XYZ switch says it's not in those gears even if it is.

A faulty XYZ switch will also cause the M&S lights to flash and either the incorrect gear to be displayed on the dash, or for the dash gear indicator to blink.

Try starting in neutral by moving the shifter to neutral BEFORE turning the key on, then see if it will go.

If it is the XYZ switch, the auto will also go into limp mode and prevent 1st, 2nd and most likely 4th gear from being used, it will also prevent converter clutch lockup.

So limp mode should only be used to "limp home", if the M&S lights aren't flashing, it should be ok to use.

Cheers

No i haven’t scanned for faults, is there an app i can use?

[shack]

No i haven’t scanned for faults, is there an app i can use?

Usually a Nanocom.

Depending on what revision TCU the car has, they do have "partial" OBDII support, so you could try something like car scanner or torque pro.

[Timlandy113]

Usually a Nanocom.

Depending on what revision TCU the car has, they do have "partial" OBDII support, so you could try something like car scanner or torque pro.

Thanks mate, have just taken to a Land Rover specialist mechanic and the only fault was low battery voltage which explains the m and s flashing which have now gone off, he suggested bypassing the XYZ relay so going to get him to do that. Thanks for the help

[shack]

Thanks mate, have just taken to a Land Rover specialist mechanic and the only fault was low battery voltage which explains the m and s flashing which have now gone off, he suggested bypassing the XYZ relay so going to get him to do that. Thanks for the help

You could have battery issues for sure, low battery during cranking and XYZ faults are well documented.

I still however think you have a faulty XYZ switch, as sitting for 20 minutes with the engine off won't fix a wonky battery!