[ar35s]

Veichle: 1992 w124 E220

The problem is: no kickdown most of the time - let's say it works OK once in a while (e.g once a month).

Otherwise the transmission works greatly.

I checked the kickdown switch and it seems OK.

I also measured if +12V is present at the kickdown switch - no results with engine on in P,N and D (at idle and with handbrake applied) position.

I see from the schematics (it is a 6cyl w126, but it should be very similar to mine) the kickdown +12V passes through a relay in the fuel pump relay module (pins 15 and 87k).

Now my questions are:
1. Which parameters controls the kickdown relay in the fuel pump relay module - on which circumstances the circuit should be open (no voltage at kickdown switch) ?
2. Should be +12V present at the kickdown switch in "D" at idle?

I still have to check the voltage directly at the pin 87k of the fuel pump relay module.

If the answer to (2.) is positive, I guess I'll have to order a new FPR.

TIA

Gregor

 

[mike690003]

replace the kickdown switch, it is about $30. Yours may be working intermittently, and could be the cause of your problem.

 

[vili1982]

nice rims

 

[ar35s]

The kickdown was working OK the last couple of days.
I was also able to measure +12V at the kickdown switch.
Today it is dead again. And zero volts measured.
I guess it is some bad soldered joint at the FPR.