My sort of broken W221 S600

[LincolnLovin]

Love this, fingers crossed you can get it sorted.

[confused_buyer]

If you are getting errors on all speed sensors it may well be the abs unit. They do go wrong.

You could try unplugging the multi connector from the main abs controller and spraying contact cleaner on the pins and reconnecting. Can sometimes help. If not the abs unit might need rebuilding.

Depending on the model year it might also have a second battery behind the back seat. If these start to go bad it can cause all sorts of odd electrics

[Fastdruid]

Mikedknight said:

Misfire update. It still has one. It was only misfiring on one cylinder (cyl 7) so thought I’d do the spark plugs. The last time they’d been done was in 2012 30k ago.

Replaced them all with 24 NGK iridium’s which didn’t fix the issue so I’ve ordered the left coil pack. On further reading of the service history it turned out the spark plugs had been changed last year less than 1000 miles ago! Doh.

To be fair, I've chased my tail before over a misfire and excluded the (obvious) of it being a spark plug "because I'd just changed them"... They can and do fail and sometimes you get DOA ones even with reputable brands.

So while yes it's annoying that they were only done 1000 miles ago it still could have been them (just a shame it wasn't).

[Exboxster1]

Bought a 320cdi recently, the unicorn ULEZ friendly version.
Having read your post I've cleaned about a kilo of crud out of the under bonnet drains.
Thank you !!

[Mikedknight]

Good news on the 320cdi, I also have a 320cdi that is full of soil in the same place.

On to the 600 replaced the left coil pack and all was well until the EML lit up again. This time the codes are banging on about the voltage transformer but weirdly the live data isn’t showing any misfires.

I guess I need to buy a voltage transformer too. I’m not touching it for a couple of weeks now but I’ll report back my findings.

[Mikedknight]

This cars faults have taken a sort of funny turn. The abs traction heavy steering fault comes and goes. But I had a new and exciting fault yesterday. Waiting in traffic individual suspension struts started raising on their own in the most aggressive style. Sort of like one of those LA lowriders. Accompanied by an ABC fault message on the screen. Did it for maybe 30 seconds and then stopped again.

So many weird problems with this car, anyone got any ideas? Some kind of earth fault? Dodgy alternator? Sam unit? At times it drives completely perfectly with no errors and everything working.

[mwstewart]

Those kind of faults are often earth or water ingress related. The ABC module is behind the passenger foot rest/foot well. Is it damp there?

[Mikedknight]

mwstewart said:

Those kind of faults are often earth or water ingress related. The ABC module is behind the passenger foot rest/foot well. Is it damp there?

That’s interesting it was damp under there. Thought we’d resolved it and dried it out. Maybe time to take another look.

[mwstewart]

It would be worth removing the ABC module to check inside for water damage, and if damp then put it in the airing cupboard or similar overnight. Post some pics of the insides if you do go that way.

[Mikedknight]

mwstewart said:

It would be worth removing the ABC module to check inside for water damage, and if damp then put it in the airing cupboard or similar overnight. Post some pics of the insides if you do go that way.

Sounds like a plan. Cheers

[Smokey Bear]

I find putting a dehumidifier in a car is fantastic for drying it out. Might take a night or two nights, you’ll know as the collection in the reservoir slows down. It’s a super way for drying those foam backed carpets which would be otherwise nearly impossible to dry out.