Murtu

This has happened to me about 7 times now in the past 3 months that while driving and I try to accelerate, there is a delay in the car accelerating and then only at snail pace. There is a total loss of normal power almost as if there is a limiter that has kicked in.

My model is a 2001 C200 Kompressor (W203) with automatic transmission.

Symptoms and observations:
• No errors or warnings from computer.
• Has happened every time after car has been running between 10 and 40 minutes from a cold start in the morning or later during the day – don’t recall it happening after restarting when the engine was warm or hot.
• No gear kick-down when the accelerator pedal is floored or tramped all the way for the forced gearing down.
• Normal gear change - automatically from low to high when accelerating.
• Normal gear change – automatically from high to low when slowing down, or stopping, and pulling away or accelerating.
• Gears change when manually changed – gearshift pushed left or right.
• When at a standstill, and gearshift put into neutral and the accelerator pedal is floored, the engine only revs up to about 5000 rpm maximum and takes about 3 to 4 seconds to get there.
• When the ignition is switched off for about 30 seconds and restarted, the fault clears and the car functions normally gain, or when left overnight. Have always removed key as well when switching off.
• When in autocruise mode, disengaging does not clear the fault.

Could this be a simple case of contact corrosion on a plug or a relay? Where reseating could solve the problem? If so where do I start? I am not a car mechanic but I am quite technical. Don’t have a service manual either as they are apparently not in print yet.

It has happened to me in peak hour freeway traffic when it is dangerous to change lanes and sometimes impossible to pull off the freeway to switch off and restart and I will appreciate any suggestions to help me rectify this fault.

Regards
Murtu

Glyn M Ruck

I'm reluctant to even comment - this is how long is a piece of string - you need to get the vehicle on to an analyser with a competent operator or get input from one of the pros on this forum like Buellwinkle.

It sounds as though the vehicle might be switching itself into "limp home mode" intermittently. This can be caused by earthing problems. I've seen this on Opels where brass bodied sensors are screwed into aluminium. You get some catalytic corrosion taking place and it causes mayhem with the ECU. e.g. temp sensor does not earth properly ECU thinks the car is cold - overfuels like hell and then switches into limp home mode. Throttle switch can also cause problems. The dealerships who are hopeless at diagnosis always want to replace the ECU which is fine. All you need to do is clean threads on the sensor - apply some conductive paste and all is well. When you restart you reboot the ECU.

I've not been of much use but maybe it will spur one of the old hands to give us the benefit of their wisdom - even if it's to tell me I'm wrong

dmatre

I had a similar problem 1 time. Turned out to be the throttle position sensor. I could put the pedal to the floor, and the car would just barely accelerate. Put the car in neutral and it would slowly rev up.

Replacing the TPS resolved the problem for me. Hope yours is as simple.

ArsnlKen

Yeah,could be anything. Mine did that a couple times & after I re-set the throttle its back to normal driving. If you arent sure how,there's a thread that walks u thru it. Nothing hard or involved at all

Glyn M Ruck

Murtu,
This is a bit of a can of worms and unless the dealer can pick up the problem on an analyser he is going to do it by trial & error. You may as well too.

Here you have 2 people already that have had this symptom from what I in old Bosch speak call the throttle switch & they more correctly call the TPS.

Check out the TPS - you might get lucky! It has been a common gremlin in Bosch systems for many years. Cleaning and adjustment is all it usually needs