After jump starting having problems

[ice643]

Hi
my car was parked up for a couple of months last week my son jump started the car with cables.
over the weekend i took the car out and the gears wont go into tiptronic also s and w mode doesnt work.
Also the super charge r isnt working, i think its in limp mode.
I asked my son and he did tell me that the cables did touch at one time.
i have disconnected the battery to see if any thing happens but still the same.
Any ideas fellas i think something hasblownI changed the ic pump a couple of montha ago.
otherwise the car starts and drives fine.
Thanks in advance

 

[ice643]

sorry to mention it, its a c32

 

[markjay]

Jump starting from another car is indeed not recommended, because the higher voltage generated by the other car's alternator could damage electronic components (and vice versa - in fact both cars are at risk).

The correct way of dealing with a flat battery is to jump-start it from another 12V car battery (i.e. not connected to a vehicle), or by trickle-charging it.

Said that, it is impossible to say if the issues you describe are the result of damage to electronic components during the jump starting, or other unrelated faults. A good place to start would be to get the car on MB STAR diagnostic computer and check for faults.

One other thing to consider, is that electronic components on modern cars don't work very well when the battery is weak or faulty.

I would try trickle-charging the battery (using CTEK charger or similar) until it's fully charged, then check again how to car behaves. Failing that, I would fit a new battery (or at least a known-good battery) and see how the car behaves before condemning any malfunctioning electrical components.

 

[ice643]

Thanks

 

[grober]

And check your fuses/SAMs!

 

[ice643]

And check your fuses/SAMs!

i checked all the fuses they look fine,also when i use the gearlever it jerks.Iam going to put a new battery on, will the car need to be driven before everything is back to normal.
Thanks again for the replies .

 

[grober]

You may have blown one or more of the fuseable links in the prefuse unit. Here's an example in a later GLK.

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[ice643]

i took the car to auto electrician today he put it on a machine and told me its the transmission control unit,the fuses are all ok.Could it have blown the TCU.

 

[grober]

He may be refering to the TCM [transmission control module] Part no A0325453232 its usually hidden behind the front kickplate in the passenger footwell. You may be able to pick one up second hand but check the part no of the one fitted in your car. There are known problems where this unit connects to the gearbox via a round plug which can get contaminated with oil so check that also.

 

[ice643]

He may be refering to the TCM [transmission control module] Part no A0325453232 its usually hidden behind the front kickplate in the passenger footwell. You may be able to pick one up second hand but check the part no of the one fitted in your car. There are known problems where this unit connects to the gearbox via a round plug which can get contaminated with oil so check that also.

Thanks for the reply,is the round plug accesible from the foot well or do you have to underneath.
Thanks again

 

[zipdip]

you have to go underneath the car for the plug

 

[grober]

Underneath I believe here's a link that will help.
You are being redirected...

however having had the fault located to the transmission module already - presumably by fault code??? you might try replacing/repairing the transmission module first---- they come up second hand on Ebay from time to time or some specialist companies may offer a test/repair service- what did your garage guy recommmend?

 

[ice643]

Underneath I believe here's a link that will help.
You are being redirected...

however having had the fault located to the transmission module already - presumably by fault code??? you might try replacing/repairing the transmission module first---- they come up second hand on Ebay from time to time or some specialist companies may offer a test/repair service- what did your garage guy recommmend?

He put it on a maxidas machine and said it was the TCU.cleared the fault .
Iam going to get a second opinion, could it just be the connector.
Also the car drives would you say the fuses are fine.
Thanks

 

[grober]

Right he cleared the fault code on the TCU. Does the car now start and drive OK? i.e. does the transmission work as it did before before the jump start incident. The TCU may merely have experienced a voltage spike which threw a code whch has now been corrected??

 

[ice643]

Right he cleared the fault code on the TCU. Does the car now start and drive OK? i.e. does the transmission work as it did before before the jump start incident. The TCU may merely have experienced a voltage spike which threw a code whch has now been corrected??

he cleared the fault but it still drives the same.limp mode.

 

[markjay]

he cleared the fault but it still drives the same.limp mode.

Clearing the fault codes does not fix any faults as such, and should make no difference to how the car drives.

This is done purely for diagnostic purposes, i.e. if on re-check the fault code did not come back, then you know this is not your issue.

If the fault code does come back, then it *might* be your issue, though at this stage it merits further investigation.

But the main purpose of erasing the codes is simply to make sure they are not just 'stored' codes, i.e. a reminiscent of a historical issue that is no longer 'present' (and to avoid the wild goose chase of looking for a fault that no longer exists).

 

[grober]

So has the fault code come back?It would be useful to know exactly what it was or did it merely indicate a faulty TCU. You may need to use the Mercedes STAR diagnostic machine to get a more precise read out.

 

[ice643]

Thanks for all the replies I am in West Yorkshire does anybody know a good specialist with a star.

 

[ice643]

So has the fault code come back?It would be useful to know exactly what it was or did it merely indicate a faulty TCU. You may need to use the Mercedes STAR diagnostic machine to get a more precise read out.

I m going to go back to the electrician today I don' know what the codes were it just indicated TCU.

 

[moog999]

Don't piss about taking it to a generic auto electrician.

Take it to:-

Car mechanics from Prestige Motor Engineers

They're in Wakefield (Osset). They have the proper kit to suss out what's wrong.