2003 W211 320 CDi Running on and ignition problems

[Holmey]

Bought what I thought was a mint FSH 130,000 03 E320 CDi, but having trouble with it already

I intended driving down to Birmingham this morning with a friend, and when I got to his house and turned the key off and removed it, the engine carried on running, and when I managed to get the engine to stop, (by sliding out the front ECU connection plug in the fuse box), the key wouldn't turn, and the cooling fan was spinning away even with the key out. Also, when I tried to start it, the lights on the dash would go on when I put the key in, (and the cooling fan stop), but the key wouldn't turn. All the time, the steering lock was off. It also flashed up and SRS and ABS malfunction warning.

A quick google suggested the possibility that it was the battery, so I removed and tested the battery and not only found that the battery was not up to par, but wasn’t the right battery for the car, (it was too small/low capacity), so I bought and fitted a new correct battery for the car, (£180 – Ouch).

As soon as I fitted the battery, the alarm went off, but it would allow me to turn the ignition on and start the car, the problems being, it still wouldn’t turn off again, and when I stopped the engine by “pulling the plug”, the key wouldn’t turn again, the SRS and ABS warnings were still on and the only way I could start it again was by disconnecting and reconnecting the battery, something that would again allow the car to be started once, then everything back to how it was :-(

Any ideas guys? I can’t get it on any diagnostics until morning, but any suggestions/ideas welcome.

 

[LostKiwi]

Check and clean the earth points for the ECU and front SAM.

 

[mersum1es]

Fan at full blast --> check ALL fuses (also in passenger footwell pre fuse box), and earth straps like LostKiwi said

Check BCM, If I remember, that kind of battery disconnect (which in any other circumstances won't do anything good but allows only accidentaly current spikes) was reseting system.

 

[LostKiwi]

Fan at full blast can also be caused by canbus failure.

 

[Uncle Benz]

Needs to go on Star. Anything else is guesswork, but if I were a betting man, it’d be on the EZS.

 

[Holmey]

EZS.

???

 

[Uncle Benz]

Ignition switch

 

[Holmey]

Sorted it

Searching around the Internet I found a few other people who had had the same problem, with a common denominator being that it happened in the wet or after washing the car, with me just having had the car washed before this happens. Turns out, if the top of the fuse box isn't clipped on properly, water spray on the bonnet edge can end up letting water into the fuse box.

Having fitted a new battery, (that was needed, the one fitted not only being below par, but the wrong battery), I disconnected both batteries, (the small one under the bonnet tested fine), sprayed WD40 all over the fuse box and other electrical systems, left it overnight, then when I reconnected them this morning, the car was fine

Thank Ye Gods for that, I was expecting a massive bill and feel I've come off light with £180 for a new battery that was needed.

 

[Wighty]

Ignition switch

EeegZnition Switch ?

 

[Wighty]

Sorted it

Searching around the Internet I found a few other people who had had the same problem, with a common denominator being that it happened in the wet or after washing the car, with me just having had the car washed before this happens. Turns out, if the top of the fuse box isn't clipped on properly, water spray on the bonnet edge can end up letting water into the fuse box.

Having fitted a new battery, (that was needed, the one fitted not only being below par, but the wrong battery), I disconnected both batteries, (the small one under the bonnet tested fine), sprayed WD40 all over the fuse box and other electrical systems, left it overnight, then when I reconnected them this morning, the car was fine

Thank Ye Gods for that, I was expecting a massive bill and feel I've come off light with £180 for a new battery that was needed.

Excellent investigation and fix buddy