CLK 320 kickdown problem

[EuroCLK320]

I have just put a new battery in my '99 CLK 320 (may have nothing to do with this kickdown issue). I took the car out today and noticed the kickdown is doing something very odd. The revs leap to around 4,500 but the speed does not increase. I can hear the engine racing but the speed just stays constant.. almost like clutch slip in a manual gearbox.

Driving around normally I have noticed no problems with the gearbox.

Any ideas?

 

[television]

I have just put a new battery in my '99 CLK 320 (may have nothing to do with this kickdown issue). I took the car out today and noticed the kickdown is doing something very odd. The revs leap to around 4,500 but the speed does not increase. I can hear the engine racing but the speed just stays constant.. almost like clutch slip in a manual gearbox.

Driving around normally I have noticed no problems with the gearbox.

Any ideas?

First thing disconnect battery and leave car for 10 mins,then re connect, see what happens.

malcolm

 

[EuroCLK320]

Thanks tried that but its made no difference.. apart from now the car seems to be rough running when in Drive and often doesn't want to change up during normal driving also. It's generally become unwell since I replaced the battery to be honest. The battery was off the car for around 4 days. Is there maybe something I should have reset apart from BAS and windows?

I have also noticed that in Park the engine seems to hit a physical limiter at about 4200 rpm, is this ok? Incidentally, this is also the rpm it seems to climb to during kickdown (but as mentioned at the start of this thread it then displays the symptoms of a slipping clutch in a manual gearbox)

addendum: Could this be a MAS problem. Are the MAF and MAS different things? Is it sometimes called an Air Mass Sensor as I have found one of those on Euro Car Parts Any idea where they are located on a 99 CLK 320 cabriolet? Its all very confusing HELP!!!

 

[jberks]

I have also noticed that in Park the engine seems to hit a physical limiter at about 4200 rpm, is this ok? Incidentally, this is also the rpm it seems to climb to during kickdown (but as mentioned at the start of this thread it then displays the symptoms of a slipping clutch in a manual gearbox)

Yes, the rev limiter is around 4200 when out of gear so you can relax on that one.
As regards your problem, it does all sound like safe mode for the ECU. Why it should do this after a battery change I am unsure, though extra voltage, current surges can have some nasty effects on some components.
So, I'd say you've either fried your ecu when reconnecting the battery or else there is a co-incidence and a sensor has gone down. Get the codes read as a starting point to rule out MAS etc. If (worst case) the ecu is fried, then they can be repaired so don't be conned into a new one.

 

[EuroCLK320]

Thanks.

Main dealer to get the codes read i guess?

 

[television]

You could check the fuses in the box in the passenger foot well box.

Malcolm

 

[EuroCLK320]

Thanks to all.

Bought a new MAS on EBAY, fitted it and I have the car I always thought it should be at last. This MAS must have been going when i got the car a year ago!! Kickdown is back.. engine is smooth again.. crisp acceleration, goes right to the red line etc etc Thanks again

 

[saphire]

clk320 no kickdown no power etc

hello all
after over a year of no kickdown,misfires limp home,
have finally got it fixed,
1xBosch MAF,
12x spark plugs,
and the final piece of the jigsaw(1x petrol filter)
all of the pieces were not good,but it needed all
of them to cure my problem,unfortunately I had
to have it done in a French mercedes dealership,
not cheap but cheaper than UK.
Mike