Hi every one ,
i have a 95 e320 which i have changed the junk harness of the car with the delphi one used. car runs fine and things are ok but one thing i've noticed is that there is no more forced kickdown. i tested the button and the switch and both are fine. tested the current coming to the solenoid valve which is one + terminal .....it doesn't have power.
1. i've tested all fuses and relays and their fine.
2. checked the switch and it responds when you power it up.
3. under pedal switch was tested and it works fine.
4. before the harness changing it used to be fine but now no force kick down.

if any one have any clue or hint plz let m know, like where to dig and whether to find solution for this or not.

thanks you all,

MOe

 

I owned a '95 E320 since new but sold it after 15 or so years at 145K miles with only the main harness replaced.
Make sure that your throttle harness is also replaced. Most likely your issue from all I read on the internet.

Mercedes knew about the bio-degradable wiring back in 2003 with less than 100K miles and never recalled these cars. Shameful.
I know because they wanted to replace mine for thousands of dollars back then. They pretended that my car was a one off case and claimed I must have let the engine overheat for extended periods.

Anyways, make sure your throttle harness is also replaced. It is made of the same biodegradable cabling.

Happy Motoring

 

Hi mate thanks a lot for your reply, but i have already changed the starter cable and the throttle body harness as well cause those trios were the main issue for every w124. but the funny thing is the solenoid was working fine before that now no power coming to it after replacing the engine main harness. if you have nay clue where this harness for the forced kickdown switch is i can trace it and see where the issue is. any help will do.

sincerely yours,

Moe

 

I do not know the particulars of the kick down switch but since the problem stated after you changed the harnesses, the culprit could be in the harness itself (not) or the installation.
Can you not trace the kickdown switch wiring from electrical diagrams? Does it go straight from the gas pedal to the ECU?

 

Hi mate,
actually i found the solution for this problem but forgot to mention it in the group. now its a good chance to do so. i've traced couple of article about kick down switch issues and found out that their all relating the issue to the clima sensor. usually the test for the clima sensor is that you start the ac and see if the rpm do go up or stays down and then you know that the clima sensor is working. but never crossed my mind that the clima sensor is in charge of the kick down solenoid switch. all what i know is that the under pedal switch gives the signal to the clima sensor and the clima do forward in different signal upon its approval as a device to the solenoid valve. it keep the approval on your request for the kick down as a safety feature to protect the car.

funny thing in my car was the clima was working fine with the ac requirements but with the kick down thing it wasn't working. i got to know about it from replacing it with my brother car one and checked that the solenoid valve is working.

how to test the clima solenoid valve responding or not.....simple open the switch fully all light are on in the dash....car is off.....fully press the button underneath the pedal by hand by foot by pedal whatever you feel like to, and some one must be underneath to check the solenoid valve whether its clicking or not.
this way you know whether you have a closed loop or not. if not their might be couple of things ......
stuck solenoid needle.
damaged solenoid.
no power coming to solenoid.
clima sensor damaged.

you can test whether there is a positive signal coming to the solenoid with a multimeter cause its a single pin positive and negative from the body. you can test the valve by supply +12 from the battery while the car is totally off and see the clicking in the valve to know whether its working or not.
schematics i can trace the circuits but cant read it in full.

wish you the best

Moe

 

Thanks for posting. Yes it sounds like the when the kick-down fuel enrichment is activated the AC compressor is also turned off to get you an extra 5-8 HP of available power to the wheels instead of the AC. So this all makes sense for a high level functionality.

A similar function but in reverse is done in earlier KE-jetronic system, when the AC compressor is on the fuel cut off is turned off, so that the jolt is less in deceleration because there is already a load on the engine and you want to avoid both happening at the same time (Compressor turning on and fuel cut off)
I should check to see if in full throttle the AC compressor is also turned off. But in any case the ECU and the Klima are talking to each other for these reasons even in earlier models.

Glad you figured it out

Happy motoring!