Speedtronic, Cruise Control, Auto in LOW GEAR

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cis5a1

New Member
Joined
Aug 29, 2008
Messages
4
Location
Bedfordshire UK
Car
W203
Automatic in Low Gear, Speedtronic, Cruise Control etc

Speedtronic, Cruise Control, Automatic stuck in LOW GEAR (sometimes), Speed Limiter

If you have or having any of the above problem it could be because the BATTERY WAS NOT TOPPED UP WITH DISTILLED WATER? i.e. THE 100AHr BATTERY acting as a 30AHr BATTERY - big volt drop on starting!

(The following I listed in another Mercedes Forum on the web - worth listing here also)

Mercedes and the Battery (Water Level) – Speedtronic, Cruise Control, Stuck in Low Gear, etc.

The car a 2002 W203 C Class 220CDI Saloon Automatic Gearbox. During the winter of 2007/2008 on about 4 or 5 occasions I would drive off in the car only to find the cars automatic gearbox would not change up. However, on stopping and turn off the ignition and restarting the car functions as normal. I mentioned this to a Mercedes mechanic before I had my last service (3rd) – said see how it goes!

Moving on to October 2008, the car was left for about 10days in a car park, on my return – yes, you guessed, the auto box would not change up until I stopped and restarted. Then it was OK.

In search of a solution I posted a “New Thread” on the mercedesclub.org.uk Forums and had a very quick response (thank you) most suggesting “Get a New Battery”. So I decided I would get one the next time I have a day off work v – after all the car auto gearbox works OK if I stop and restart.

During a two week period I had to stop and restart the car about 6 to 8 times all was well. However, on the 25th November 2008 the trick of stopping and restarting did not do the trick, so I had to drive home about 15 /17 miles in a low gear at about 25+ mph. The same evening I had a look at the battery, which is hidden under air filter housing, after unclipping the housing I could see the battery was the top-up type with 6 screw-in plastic plugs. I removed all 6 plugs, looked into each cell, but could NOT see any water/acid?
I then decided to top up each cell (filtered rain water) to a level of about 1/8” over the plates (I use to do in a former life as an Electrical Technician). What was surprising is I used about 750ml (may be 1litre) of water to get the level just over the battery electro plates. THIS WOULD EXPLAIN THE BATTERY PROBLEMS.

The following day the car was connected to a portable MB Star Diagnostic computer system. The Diagnostic computer screen had most of the cars electrical system marked with a CROSS (X) i.e. shut down/ not working. The MB Technician ran the program about 3 times and managed to clear all the errors – now each electrical system now showing a TICK, and HEY PRESTO the car was now back to normal, no faults on the display and the Speed Limiter working without any errors and changing gears correctly.

The MB technician said the battery was OK and did not need changing (perhaps because it now had water in it), but I still went and purchased a new battery – sealed type with a 3year warranty (from Bedford Battery, Bedford)

My conclusion: Albeit the car has been serviced 3 times (now 42000 miles) by a MB main dealer, or approved MB agent. I believe as the battery top surface is not visible a normal MB trained motor technician may assume the battery is of the sealed type and does not require any water adding to the cells. The car was just 5 years old when the problem started and may have never had any water adding in 5years??

As regards the MB in-car computer system, it seems there is a limit to the number of MALFUNCTIONS it records (every time the car has a MALFUNCTION – i.e. faulty bulb etc, or perhaps a lot of MALFUNCTIONS being caused by a voltage spike dips whilst starting) at a certain number the onboard computer system shutdown the car into Limp Home Mode – a low automatic gear.

JUST A FEW REGULAR DROPS OF DISTILLED WATER _ CAN SAVE YOU HUNDREDS OF POUNDS!
 
Last edited:
An interesting first post many thanks and welcome to the forum..:bannana: :bannana:
 
During a two week period I had to stop and restart the car about 6 to 8 times all was well.

I would hate to pick a bad situation !

BTW: Checking the battery level is mandatory on every service call. Only the lazy mechanics avoid doing it.
 

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