twonasandwich

Hi I have a 1989 w124 260e that has around 330k km (205k miles) on it.

When I first bought the car the cruise control worked fine, and then one day stopped for no reason. I've read into fixing this problem, have taken the cruise control amp out and apart which seems to be the most common problem. I have also replaced the OVP relay. But still it didn't work.

The Amp itself was fine with no signs of corrosion or deterioration. I assume the amp is functioning.

The cruise control now sometimes works intermittently when I push the stalk into accl, but then it just floors the gas pedal until I tap the brake pedal to stop the acceleration. Pushing decel or cancel does nothing. NOTE it often does nothing when pushed, this is on the rare occasion it engages.

I need to fix this problem as it has no longer just stopped working but it is quite dangerous if I am to pass it on to a new owner. I know about the cruise control actuator and throttle actuator, but I have no idea where to start looking or how to diagnose where this problem lies. ANY help would be appreciated, thanks.

Plutoe

Test the following:::

cruise control amplifier
reference resistor
road speed sensor
cruise control actuator
stop lamp switch
main ground(behind IC)

FYI---one is faulty!!

inranraaj

I do encounter the same problem for my 230E W124 model auto cruise system but my case are when I push the stalk to operate the system it works fine but the problem is the car jerks. Something that might be weak in motor that pulls the accelerator cable but I don't know where and how to find the parts that operate the auto cruise system.

Plutoe

OK you have recognized a problem(established a hypothesis)---now what do you do next---test the hypothesis---how do you do that----you have an 8 or 16 pin diagnostic socket on your car-----get a pulse counter and start testing---were there any CC faults??

Now if none of this makes sense(everything in life aint free)---open your wallet and find a mechanic who does??