W220 S500L Computer fault

[V8mate]

Hi all. I've bought myself an '03 S500L.

I have to wait for the docs so the car is currently off the road. On arrival, the dash was saying that the tyre pressure system was faulty.

The battery suddenly went dead after a week (dropped to about 6V). It wouldn't take a charge so I bought a replacement from MB. The car was without a battery at all for about 18 hours.

Noticing the tyres were all pretty low, I had a mobile fitter out to replace them all.

I then thought I'd reset the pressure sensor circuit. But, I can't get the left-hand bank of steering wheel controls (up/down, menu up/down) to work at all. (The right hand side radio volume control works fine)

The screen is also showing a fault with the pre-safe now. I'm assuming (always a bad idea!) that this occured because of the battery removal. The handbook says this only works above 20mph, so will this reset itself once I drive the car again?

Could the battery removal have affected the steering wheel controls for the computer? If not, has anyone else had a failure of the wheel control buttons?

Thanks in advance for your advice guys

G

 

[Diesel Benz]

This car must be using a Beru TPMS system. The early control boxes were error-prone, no flash update, usually the advice was to replace with a new one. Would be interesting to have the part number of your controller.

Disconnecting battery should not be bad if you just take care of the necessary procedures afterwards. It should not be more than the windows, sun-roof and the steering, perhaps something else. I don't see the current issues related to the battery change.

 

[Dieselman]

Doesn't the SL lose various programs if the battery voltage gets too low for too long. I think max duration to stand is about two weeks.

 

[Diesel Benz]

Doesn't the SL lose various programs if the battery voltage gets too low for too long. I think max duration to stand is about two weeks.

I'm not aware of that but this seemed to be an S, not an SL

 

[Dieselman]

It was something said on here once..

 

[DansSlk]

Doesn't the SL lose various programs if the battery voltage gets too low for too long. I think max duration to stand is about two weeks.

Nah, it's a myth (that was not accepted by a previous member of this site). All the car's will inhibit a start if the voltage drops to low and they can all shut down consumers for the same reason but they don't forget settings for years even with no power, its all stored in EEPROM.

Anyways back on topic, V8mate did those control's ever work? could be an iffy contact spiral causing that or a fault with the module or button's, you might want to check out the buttons with a multimeter or when the car is back on the road the dealer should be able to narrow it down with the DAS.

 

[V8mate]

Thanks guys.

Yours is a pertinent question - "did it ever work?". I can only say that I THINK so. I've only had the car a couple of weeks and it has spent most of that time sitting there doing nothing.

It may be that a quick trip to the garage is in order as soon as I can tax it.

Hopefully my local specialist will have the necessary diagnostic equipment to avoid a trip to the main dealer.

 

[V8mate]

*Update*

Took car into local MB dealer today. Turns out that all the problems were down to the voltage drop (and subsequent removal) of the old battery.

They reset the car and everything operates properly - including the steering wheel buttons.

Best of all - no charge - as the car wasn't ready when I went to collect it (they thought they'd do a recall item while they had the car in and hadn't completed it)