Glow plug controller

[Batsford]

Does the kx040-4 have a glow plug controller And if so where is it located?

 

[North Idaho Wolfman]

I don't think it does, I do believe the ECU controls it.

 

[Batsford]

I don't think it does, I do believe the ECU controls it.

Thanks, that’s what I was worried about. My glow plugs aren’t staying on long enough to start the machine. (New glow plugs and 11.5 volts to them)

 

[GreensvilleJay]

yeesh ,if the ECU is involved, maybe there's an 'ambient temperature sensor' AND a 'water temperature sensor' that have to 'play nice' to get the engine to start ?

 

[North Idaho Wolfman]

Thanks, that’s what I was worried about. My glow plugs aren’t staying on long enough to start the machine. (New glow plugs and 11.5 volts to them)

Get the WSM and it might be able to walk you through troubleshooting the issue.

 

[Dave_eng]

Thanks, that’s what I was worried about. My glow plugs aren’t staying on long enough to start the machine. (New glow plugs and 11.5 volts to them)

I bought A KX040-4 this year before and concluding the sale I discussed cold weather starting with the dealership owner. I have a M7040 and learned of a trick to bypass the GP controller which made a major difference in starting when I had my block heater plugged in. Regarding the excavator, the owner told me when it is cold you may need to repeat the key off, key on process a couple of times to get enough heat from the GP's
Try this and let us know.
Dave

 

[Batsford]

I bought A KX040-4 this year before and concluding the sale I discussed cold weather starting with the dealership owner. I have a M7040 and learned of a trick to bypass the GP controller which made a major difference in starting when I had my block heater plugged in. Regarding the excavator, the owner told me when it is cold you may need to repeat the key off, key on process a couple of times to get enough heat from the GP's
Try this and let us know.
Dave

I’ll give that another try…..there is a temperature sensor near the thermostat that I’m going to check out as well. Thanks

 

[Batsford]

yeesh ,if the ECU is involved, maybe there's an 'ambient temperature sensor' AND a 'water temperature sensor' that have to 'play nice' to get the engine to start ?

Yes there is a water temp sensor I’m going to check out. Thanks

 

[Batsford]

Get the WSM and it might be able to walk you through troubleshooting the issue.

Yes, I just down loaded one…..looks like it get into the A/C unit more than anything else!

 

[GreensvilleJay]

Since you've replaced all the plugs, have good voltage and the machine runs, so unlikely the ECU.
Hopefully the WSM has the specs for that water sensor, how to test and maybe what temperature the ECU looks at to control the glow plugs, and HOW the ECU actually controls the power to glowplugs.
If, say the ECU reads the sensor as 'warm' when it's actually 'cold', then the ECU probably won't heat the glow plugs as much and that could cause 'hard starting'. Maybe check the wiring from sensor to ECU.
Most electrical problems are a series of 'test and eliminate, next' but you need the WSM/ wiring diagram, and you've got that. Check WSM for a 'trouble shooting check list' ?

 

[Russell King]

Thanks, that’s what I was worried about. My glow plugs aren’t staying on long enough to start the machine. (New glow plugs and 11.5 volts to them)

Do you have any block heater installed? (Is the water in the engine being warmed by any method? is a better direct question really)

 

[PoTreeBoy]

Thanks, that’s what I was worried about. My glow plugs aren’t staying on long enough to start the machine. (New glow plugs and 11.5 volts to them)

One kluge you could try. Since the plugs are powered in the start position, put something in gear that prevents it starting. Then turn the key to start for a few seconds, the plugs should receive power but not the starter. Then put whatever you shifted into neutral to start it.

I've read here about using that trick when a block heater causes their timer to time out too quickly.

 

[North Idaho Wolfman]

One kluge you could try. Since the plugs are powered in the start position, put something in gear that prevents it starting. Then turn the key to start for a few seconds, the plugs should receive power but not the starter. Then put whatever you shifted into neutral to start it.

I've read here about using that trick when a block heater causes their timer to time out too quickly.

KLUGE?


noun: kluge

1. an ill-assorted collection of parts assembled to fulfill a particular purpose.

Good thought, but I don't know if that would work on a Mini EX.
I don't know what he could put in gear to override it, as everything is hydraulically run.

 

[PoTreeBoy]

KLUGE?


noun: kluge

1. an ill-assorted collection of parts assembled to fulfill a particular purpose.

Good thought, but I don't know if that would work on a Mini EX.
I don't know what he could put in gear to override it, as everything is hydraulically run.

In the spirit of the times, I feel entitled to redefine and use words as I see fit . I don't know if it would work either on a mini ex, surely something prevents it starting, travel control? OP would need to confirm that it doesn't also inhibit the preheat.

 

[Dave_eng]

One kluge you could try. Since the plugs are powered in the start position, put something in gear that prevents it starting. Then turn the key to start for a few seconds, the plugs should receive power but not the starter. Then put whatever you shifted into neutral to start it.

I've read here about using that trick when a block heater causes their timer to time out too quickly.

I am the one who happened to learn about my M7040 GP trick which I have posted on the forum several times over the years. It was my same dealer owner who I asked about ways to improve cold weather starting on the excavator I was about to buy. He said just use repeated ON until GP indicator goes out then Key off. Next just repeat the cycle. The M7040 trick did not work on the excavator with much newer engine controls.

Dave

 

[Batsford]

I bought A KX040-4 this year before and concluding the sale I discussed cold weather starting with the dealership owner. I have a M7040 and learned of a trick to bypass the GP controller which made a major difference in starting when I had my block heater plugged in. Regarding the excavator, the owner told me when it is cold you may need to repeat the key off, key on process a couple of times to get enough heat from the GP's
Try this and let us know.
Dave

Cycled it several times and still no start…new oil and a fully charged battery…..it’s around 30Degrees F here. I’m going to recheck the voltage to the glow plugs

 

[GreensvilleJay]

Maybe put a 12v 'trouble' light on the glowplug bus ? It'll light up whenever power is going to the glowplugs. It's easier than trying to read a DVM and you can 'time' it while sitting in the cab.
I'm curious, is there no 'glow plug light' on the dash ?

 

[Dave_eng]

Maybe put a 12v 'trouble' light on the glowplug bus ? It'll light up whenever power is going to the glowplugs. It's easier than trying to read a DVM and you can 'time' it while sitting in the cab.
I'm curious, is there no 'glow plug light' on the dash ?

The excavator has a black and white LCD screen to communicate with the operator about GP , auxiliary hydraulics, no charging etc.

Dave

 

[whatsupdoc]

On my small yanmar excavator the ecu simply powers a relay
to turn on the glow plugs, it uses the temp sensor on the thermostat
housing for temp readings.

The digital screen will display the glow plug symbol but the symbol is simply a bulb connected to the glow plug relay not to the CAN buss. Even if the glow plug symbol is present the plugs may not be getting power.

I went through this because I thought the glow plugs should be
activated at 40 degrees but they were not so I suspected an issue
even though the engine started fine.

Wiring diagram is your friend.

 

[GreensvilleJay]

Hay Dave thanks for the paper ! I don't trust computers that others program, the screen could lie. Putting a light on the GP bus will CONFIRM it gets power and for how long. The 'idiot light' on the LCD screen is a 'should be' indicator. Wonder if the WSM has a chart for how long vs temperature the GPs will be on ?