Eberspächer temperature not working

[MarcLindberg]

Hi
I have done some renovation of the D3L heater with new glow plug, filter and cable spades.
I have now a problem with the temperature regulation, because it keeps high heating and blowing after reaching the set temperature.
Everything else is working fine and no error. The inside room temperature is correct in the display, shown by the arrow up.
At the D3L, I have checked the seperate temperature cable comes from the controller and not the internal cable.
I would like to check the signal from the e153 controller if it sends the correct signal to the D3L.
How can I check the 'reached temperature signal' on the E153 controller with a multimeter?
Regards Marc

[Dray]

Hi Marc!

It seems that you are pretty familiar with car electronics and not at all. Please check the attached files. Hopefully there you will find the solution to your problem.

[Dray]

https://forum.james-cook-freunde.de/vie ... f=1&t=6355

[MarcLindberg]

Thanks for helping.
I have now done some measurements on pin 19 to 24 (pin 21-24 goes to the D3L)
Pin 21 controls fine the D3L by +12V to start and 0V for stop
Pin 22 jumps between 5,1V and 5,6V. I do not know why or if it is ok.
Pin 23 and 24 consequent shifts between minus and plus in differense of voltage, when the D3L must heat and when it is too hot, which is correct. The voltage was not +1,75V against Pin 25 which is the minus, it was only 0,03V, but maybe it is referenced to another Pin?....strange
Also the difference should go between +0,75V and -0,75V, but it was much less.
I tried to unplug the controller in a hour, to ensue it was power reset, but no difference.

I will later try to measure other Pins with Pin 24, to find the +1,75V as defined an test if I can make the +-0,75V difference manually between Pin 23/24.