I have never been unanle to turn the engine off before !!!

[Zippyworld]

Weirdest fault appeared on my S350 (220).

I started the car with Keyless go and it refused to start at first, it also did this the week before but with me inserting the normal key and starting. (This is the model that had the credit card Keyless GO)

It started the second time but then went a little bit haywire, the display on the dash said the car was in Reverse and it was still in Park. I couldn't move the gear lever, I had a display message saying put car in Park, which physically that was where it was.

So I had a car that was running its engine but refusing to do nothing else. It wouldn't turn off in any way. Merc service and the local Indy have never heard of it before so I phoned rhe RAC.

Whilst waiting for the RAC I went through the Fuse chart and took a couple out marked Emergency Engine Stop, which thankfully it did, so at least it wasn't gonna run dry whilst I waited.

The rescue turned up and put the fuses back in and it behaved itself, he did a factory reset by disconnecting the battery and then when it was reconnected it was stalling and running very lumpy.

Anyway at the moment I have a message on the display saying 1 malfunction, Pre - Safe Inactive, it is not showing any other fault.

RAC man who knew his stuff indicated the first place to look is the Crank sensor followed by a Cam Shaft sensor.

I am just wondering how if the Pre Safe Inactive could be cleared by driving the car ovet 20kph and has anyone else had this fault.

Bloody good job the fuse chart was still where it should have been, in the toolkit !

[e320dave]

I had an issue where my car refused to stop at 1am when I arrived in Cornwall. Not a great start to the holiday especially with the heavy rain. The car was misbehaving beforehand as well. The headlamp washers were constantly on and I could not stop it and there various warnings were all li up. Got it recovered my MB. Turns out the issue was that a drainage tube under the scuttle trim got blocked which led to the water overflowing through the heater motor and into the passenger footwell. This caused the ECU to arc. All they did was dry everyting out, unblock the drainage tube and reset all the fault codes.
Could be something similar, but then again it may not be!

[mbtech01]

This may not be related to your fault but its still worth checking - The water drain in the heater box assembly in the engine compartment blocks up allowing rain water to build up & run inside the car flooding the heater blower fan & resistor pack then basically dripping out of the heater box inside the car behind the glovebox & soaking/flooding the passenger front floorwell which then soaks all the wiring harnesses & electrical plugs running along the passenger sill together with a few control modules located under the passenger footwell floor plate under the carpet. This results in terminal corrosion & corroded wires etc which then cause all kinds of electrical faults/problems especially with the Can bus systems on the vehicle which control all the sytems on your car.
As said it may not be anything related to your problems but for paece of mind i'd check it out. Open the bonnet, then looking at the base of the windscreen on the passenger side in the engine compartment you'll see a black heater box with a grill sat on top of it. Get a light & look into it, it'll either be swimming in water or if its drained off check the condition of the rubber drain bung in the bottom, it will probably be blocked. If so unclip the grill panel & get a knife & cut the bung out in the bottom to prevent future blockages. If water is found go inside the car & lift the passenger front floor carpet & feel under it, It will probably be soaked through & will require a full strip down to investigate what damage has been caused. Chances are the wiring & connector plugs in trunking down sill panel will be corroded & rotten.
Hope this isn't whats up with yours, but check it anyway for peace of mind.

[Zippyworld]

At the moment passenger footwell appears to be dry with no signs of having been wet. The plenum chamber was half full of water when I got the car which has obviously been cleared.

I am replacing the Crank sensor then will drive the car and see what messages it gives me.

Hopefully it will message " I am fine and do not plan to take all of your money off you - how are you ?"

[e320dave]

My footwell was bone dry as well as the flooring does a good job of soaking it all up so was never felt on the carpet. I was told the ECU (under passenger carpet) was surrounded by water and I was lucky that nothing had corroded and no damage was done.

[Zippyworld]

OK, I am gonna do a check, pardon the ignorance, is the scuttle trim the bit that lines the bottom of the door way ?

[hman]

scuttle trim is normally the panel in front of the windscreen under the bonnet - where the wipers are

[Zippyworld]

Well you learn something new every day ! Thanks. I shall report back.

[mbtech01]

Hopefully the crank sensor will cure your starting problem but i think you'll find that being unable to Not turn off your engine & loads of warning lights showing is a seperate fault. If as you say the plenum chamber was full off water originally when you first took ownership of the vehicle but was sorted it would be interesting to know exactly what kind of repair was done. If the car were mine i'd still lift the passenger front carpet & check for corrosion to the wiring & electrical plugs etc as this could cause all your other problems especially if the damp carpets which act like a sponge have been left for months after the original repair you had carried out were not dried out properly.
Anyway good luck with the crank sensor repair & hope the car behaves itself.

Zippyworld said:

At the moment passenger footwell appears to be dry with no signs of having been wet. The plenum chamber was half full of water when I got the car which has obviously been cleared.

I am replacing the Crank sensor then will drive the car and see what messages it gives me.

Hopefully it will message " I am fine and do not plan to take all of your money off you - how are you ?"

[Zippyworld]

OK, had a detailed check of front passenger carpets. Had them all out and its looks pristine.
Fitted the new crank sensor and the car appears to be behaving.
I do still have the Pre - Safe Inactive but I can't find any information regarding removing this from the display.

I will give the car a run and see how I get on.

Thankyou again for your input...

[mbtech01]

I've usually found that driving the vehicle for a good 10 minutes tends to reset the pre safe system & put the warning message out (Basically recharges battery & resets sytem). It generally comes on when battery voltage starts to get low or the battery has been disconected & various systems then need resetting like the steering angle sensor (reset by turning the steering wheel from lock to lock several times with engine running). If it still doesn't go out after a road test then you may need to get the car plugged onto Star diagnostics (Mercedes diagnosis) to see whats causing the problem.

[Zippyworld]

Looks like a trip to the garage then, tried resetting by windows, seats, column, and sunroof and steering lock, just cant seem to get rid of the Pre Safe Inactive message. Apart fromthis I have driven the car every day and it is showing no fault whatsoever....