CLK 320 Acceleration Problem - PeachParts Mercedes-Benz Forum

PattiJohnson · #1 12-28-2009, 04:22 PM

Hi

This is my first post, I appreciate any help you can give me.
I have a 2003 CLK 320 that has an intermittent acceleration problem. Sometimes, while accelerating from a stop, the car does not respond. No rpm increase, no throttle opening sound, nothing. The foot goes down, but the engine continues to idle. Needless to say, this is a problem in traffic. The car has 46K miles and replacing the fuel filter did not help. Where do I start?

Thanks,

mbdoc · #2 12-28-2009, 04:57 PM

That car as well as MOST MB's after 1997 uses a throttle by wire system.

In other words the gas pedal is NOT connected to the throttle.

When you accelerate an electronic signal is sent to the fuel computer & it sends that signal to the throttle actuator.

Putting your foot on the brake pedal can keep the throttle from working.

Do you use both feet on the brake pedal?

Oracle12345 · #3 12-28-2009, 05:11 PM

you have a problem with either the input, controller or the output.

PattiJohnson · #4 12-28-2009, 05:40 PM

Thanks Doc, I was thinking as much about the drive by wire, by the way it was acting. To answer your question. One foot driver. The brake is off when the gas is on. But now I'm thinking, could a brake switch malfunction cause this? And is there a way to test the accelerator controller with a multimeter to verify proper operation. This is not a constant problem, as it's only happened four times, but it's always been at bad times.

Thanks Oracle. I need a way to check the input controller. Does anyone have a picture or parts diagram of what I'm looking for?

mbdoc · #5 12-29-2009, 08:20 AM

Yes, a bad brake lamp switch can cause that issue.
That would NOT leave a code in the traction OR engine systems.

ANY problem with the potientiometer or throttle actuator SHOULD leave a code in the engine system computer. ie: P0 120 or P0 500...good luck