Cat 325C

[pasinead1991]

Hi everyone I’m working on a cat 325 c that has no hi idle and won’t slew checked all pressure switches. Monitor gauges come on with key on and then won’t read anything it starts monitor says ECM error.
There are 2 ecu s behind the cab one has lights come on red yellow and green then red hose out and green will stay on then yellow will light up.
The ecu underneath won’t light up at all have power and ground there. It has an ecu mounted on the engine also. Its a cat 3126 engine. Is the bottom ecu behind the cab being used I believe this machine came with different engines. Was wounderin if the second ecu behind the cab is being used because the engine has its own.

 

[pasinead1991]

 

[latiff"]

The 2 ECU's behind the cab,one is for the machine itself, one is for the hammer.the one strapped to the engine is for the engine control alone.the ECU with green and yellow lights is the overall controller (engine/pump horsepower controller). The green light shows the ecu has power the ,yellow light shows the ECU isn't communicating with the monitor. So I suggest you loose the plastic cover close to right foot when you're seated and expose the monitor wire,and inspect for damage .a mouse could have chewed on it. Is the throttle dropping fire from high idle all of a sudden? This is common

 

[pasinead1991]

Thanks I will check that wiring should the lower ecu lights lite up when it’s powered up with key on.

 

[latiff"]

I think it should, what do you mean by "won't slew" .

 

[latiff"]

The lower ecu doesn't control the governor actuator, monitor, and swing brake solenoid ( if by slew you mean swing). The upper ECU controls all that.the lower ECU is strictly for hammer control and actuation. It does have a hammer right?

 

[pasinead1991]

Yes it has a hammer and I meant swing thank you for that info. The yellow light is on on the upper ecu which means no Communication to the monitor I checked all the wiring from the monitor right to the EC you all good good continuity and all the wires I’m getting a new monitor I will let you know how it goes thank you very much. The lights on the lower ecu dose not light up at all

 

[latiff"]

Before getting a new one ,explain further on " has no high idle" .let's verify if it's the ECU that's the problem, I dont think the monitor is bad

 

[latiff"]

There is a confirmatory test for it though, do you know the location of the back up switch? It's a bi directional switch, can either be pushed to the left or to the right (manual or auto).switch it to manual, and try swinging it.also try firing the engine at to high idle and see if it holds it for some couple of minutes .if it swings and holds fire at high idle,them the ECU is most likely the cause.monitor wouldn't come up in manual mode.

 

[latiff"]

In manual mode the throttle knob won't work, there's another switch close the backup switch, it's spring loaded to the middle ,it returns to middle after being pushed .left increases the engine speed while right decreases or vice versa.

 

[pasinead1991]

When I put it on manual the swing works and I can increase engine speed with the other switch next to it increase it or decrease it no problem.

 

[latiff"]

Good,the ECU is bad . The ECU is bypassed by that switch in manual position. If you haven't bought the monitor already don't bother buying. Get another ECU ,replace the existing one and storm should be over. Drop your email for installation procedure

 

[pasinead1991]

Thanks very much my email is pasinead1991@yahoo .com.
The ecu underneath the main won has me worried also it’s for the hammer you said. The lights don’t light up on that at all I guess if the hammer won’t work that’s my problem I opened it and it was very wet and corroded I cleaned as best I could but still no lights.

 

[latiff"]

Has the hammer attachment been removed and replaced with a bucket? If so replace the upper ECU first see how it works before any further step to avoid extra costs

 

[pasinead1991]

Will do thanks so much

 

[latiff"]

Welcome

 

[latiff"]

How did it go ? Were you able to get the ECU ? How did the machine react?

 

[pasinead1991]

I’m going to ireland for 10 days will finish it when I get back the owner wants to get a used ecu I’m not sure if that will work aren’t the ecu s programmed to each other. Thank you for your help again.

 

[latiff"]

Right .It'll work, as long as it's that of a Compatible C series ,and is still good.

 

[pasinead1991]

Ok thanks again.