Hi everyone Does anyone know why I get this warning knowing that when I want to start it it says the the INLET heater is on. Is there a way to turn it off please? It is a caterpillar 330D. Also, i saw that when i get that warning, the engine starts loosing power under heavy load. Thank you
That is the electronics doing their job to protect the engine from damage. Nothing to do with the inlet heater. It is a warning telling you that the temperature of the air entering the engine is too high, and no you cannot turn it off because it indicates a problem. The first thing I would suggest is to check the condition of the primary and secondary air filters. If you want more details post a Serial Number.
This is the serial number CAT0330DHMWP00639. However, when I turn the key at the beginning and even before starting, à warning pops up saying that the Inlet air heater is ON. So, what i think is that the sensor might be bad and computer things that is cold outside and keep the heater ON until it becomes hot...
More likely the relay for the intake manifold is stuck in the closed position and it’s constantly powering up the intake air heater until the inlet air temp sensor trips a warning. Check the easy stuff first. Or, not. We can point blame at the computer or the sensors and start at the most complicated, unlikely and expensive things, first. Because that relay lives a hard life. Much like me, Coaldust.
That would have been interesting information to include in your OP so as not to send us off on a wild goose chase...... Have you looked in the Monitor menus for any Diagnostic Codes, even taken a look at the temperatures registered by the various sensors.? e.g. ambient air, coolant, air intake temp, etc. If you are not familiar with the system, see the attachment. If you need a password to get into certain sections of the monitor 9992 should work, but TBH to get temp reading it should be in the basic operatore menu.
The inlet heater is supposed to come on when you start the engine cold. Its on a timer and should shut off after a few seconds. If it comes on when the engine is warm and the ambient temperatures are warm then there might be an issue. I would start with checking to see if the heater is powered up when you get that warning. If there's no power to the heater then your issue is something else.
I will look into this. What about testing the selnoid and sensor? Do you know their locations in that machine please? And how to test them? I have the tester....
Start with the simple things first. Make sure all the temperature sensors I mentioned above are giving accurate information before you go anywhere else. It could be that the intake heater is being activated by a false signal. Once you establish that then go looking for Diagnostic Codes.
I tried looking at the monitor, there are no diagnostic code up there. Other than the warning I get. I attached the screenshot of the coolant temperature and the warning that the intake heater is on even before starting the engineering. I also went and disconnected the wire feeding the heater from the solenoid, but it still shows that the intake hair heater is ON. I'm quite lost here. Do you have any suggestions please? Also, I this I should replace the temperature sensor. Is there a way to check it before ordering it? Thanks
Kindly look at my latest post and let me know if yoh have any suggestions. Thank you
Do you have an infra-red heat gun.? First thing you should do is to shoot the temperature of the housing where the sensor is mounted. Is it reading the same (or close to) temperature that you see on the Monitor.?
I don't have with me now. But the temperature 34 C degrees looks reasonable.
So the gauge on the monitor (which I assume is fed from the sensor) is reading 34C.? Based on that why would you even consider replacing the sensor. TBH the gauge reading really needs confirming with a heat gun before moving forward. Have you tried unplugging the 2-pin connector #16 at the air intake heater relay.?
I will need to get the heat gun from home and come back tomorrow. For now, is there any other thing you think I can check?
The picture showing the whole diagram is not clear, I could locate the connector you are referring to. Could you please send a clearer Picture please?
Up on top of the valve cover at the front (fan) end of the engine. Can't blow it up any more than this.
I couldn't see a 2 pin connector there. Please have a look at the pictures and let me know which one you are referring to. BTW, what I have disconnected is the the one marked in red.
That's main battery power to the relay. Not a good idea to disconnect that. The control for the relay is (I think) the arrowed 2-pin connector on the right. Alternatively you can disconnect either of the two small wires circled on the left that connect to the relay, then wrap it in some insulating tape. Those two are the wires that pull in the relay coil.
I have disconnected it. Now the INTAKE air heater doesn't turn on. What would be the next step then? Can it be that the 2 wire in the soloneid are reversed.? Just saying...I'm no way a mechanic
Is the message on the Monitor still there.? Whether it is or it isn’t you now know the inlet heater isn’t operating so you can test the machine operation to see whether or not you experience a power loss. From your OP - “Also, i saw that when i get that warning, the engine starts loosing power under heavy load.”
The machine looks normal now, thank you for you help. However, do you have any clue what's the problem with the INTAKE air heater? Why it stays on?
BTW, the intake air heater on message is gone now.
The signal wires (which you disconnected) come from the engine ECM. It will need a bit of investigation to find out what input signal(s) to the ECM trigger that output to the intake heater relay. I would guess it is something related to either air intake temperature or engine coolant temperature, or even both. Right now - dunno.
Is it ok to keep it disconnected then? It is warm here now and there is no need for the heater...
We had 3 RMX 328DLCR machines. On only one of them (the earliest), we would get the same fault. If you shut off and restarted, it was fine the rest of the day. Changed the relay, intake temp sensor, coolant sensor, had software updated at least 3 times over the life of the machine. Never did find a cure, but, it was definitely the intake heater staying on.
You could do. Then when the weather turns cold you could plug it back in if necessary.
Here is an update. The Intake heater ON apparently disappears after starting the machine for a bit. But the other alarms "intake air temp high" comes after just few minutes of work. I went and used the infra-red heat gun to check the temperature of the intake manifold. The temperature came out 67 degrees Celsius. Then I went and checked the monitor, obviously there is no temperature data for such sensor but the coolant temperature was 108. Does thus mean anything? I'm really getting stuck here and can't figure out the reason behind that warning.
You could leave the 2 pin connector off and check for power with a test light on the output side of the solenoid. (Big red wire going to manifold) If there is no power, solenoid is ok and it’s something else. If there is power, This will tell you the solenoid has closed contacts internally causing the grid heater to constantly run. Will need new solenoid.
If that solenoid were internally "closed", the batteries would be dead in the morning.
Good point didn’t think of that. Maybe the operator is extremely well disciplined and turns off the isolation switch straight away.
108deg c, wonder if the fan isnt ramping up? Explain high intake temp and radiator temp. Or blocked with debris.
The fan is runing fine. Is there anything else i have to check? I just replaced outer air filter Here is the coolant reading. Is that acceptable ?
I sometimes do it but rarely.Heymccall is right the battery never dies here...
108C is definitely high. I would expect high 80’s to mid 90’s C. Can you take a picture of the cooling package? Material and dirt can build up in and between the cores.
A normal coolant temp would be as Cliffy says, high-80s to mid 90s. Something strange when the implement hydraulic oil cooler and the radiator are both in the same cooling pack yet one registers 108 DegC and the other only 68 DegC. How hard had the machine been working and for how long when the photo of the temperatures on the monitor screen were taken.? Have you checked actual temps of the radiator & hydraulic hoses to/from the cooler with an infra-red heat gun.?
I just checked coolant as it wasnt flushed since à long time and thought this might be the culprit. Please let me know if those values are reasonable or I need to replace it. See pictures attached including the radiators Thanks
More pics
Easy way to test temperature sensors without diagnostic tools, is first thing in morning before you start the machine go into the monitor and look at readings. All should read the same as ambient temperature.
Cleanest cooling package ive seen in a long time
I will do that first thing tomorrow. What about the coolant test? Did you get a chance to look at the pictures please? Do you think it is bad and need to be flushed?
That coolant test only checks freeze/boil points. It will not tell you if a flush or change is required. For that you would need to either use test strips or purchase a coolant sample kit from your Cat dealer and send it off for analysis.
Honestly i sample at most 1000hr services and change it when something fails, usually about 5000hrs on water pumps ect. Never had to add extender yet.
first you have to work out if its electrical issue or physical heating up. Please compare your monitor readings to your temp gun reading. That will tell us if it really is running hot.
Where should i point the gun to know the physical temperature of the coolant please?
top and bottom tanks of radiator or hoses. Anything dark coloured or black.
If you are in any doubt about the coolant condition get a sample kit from your local Cat dealer and have a coolant analysis performed.
Hoses #7 & #8 in the diagram below. The temperature of #7 should be hotter than that of #8.
The sensors are reading same temperature when the machine is cold. I believe sensors are good. I will check with geat gun if temperature is reasonable ones it is hot. By the way, i also noticed before that the hose coming out of the over flow coolant tank was clogged with dust. Ones i cleaned it the machine performed better but still having high temp warning coming.
Something to consider...last April, the CAT mechanic came to work on my CAT 320C air conditioning. While the AC system was being charged he had some slack time and he got some alkaline cleaner and sprayed my radiators on the CAT. I watched him clean about 2/3 of the "fins"...lots of dirt was freed up by the alkaline cleaner and he used a water hose to flush the loosened up dirt out. Then the AC finished charging and he said I could finish the job once he left. He left the balance of the gallon of cleaner with me since I was paying for a full gallon as part of his work. I didn't do any more cleaning. Then in June when it got really hot here, I started showing higher than normal engine heat temps. I finished the radiator coil cleaning job and all has been good since. Ambient temps down here lately near 100F and engine temp stays good so far. Here is a video of how it works...initially there was a LOT of dirt/dust getting washed out...well worth doing:
Today, I started the machine first thing in the morning, after around 5 minutes the "high inlet air temperature " came up again. I pointed my heat gun on different components including the inlet air manifold, the temperature was below 40 celcius. Please see attached pictures. Any suggestions please?
Looks like either multiple sensor failures or a wiring/earth related issue. I have had problems with high resistance from the earth strap on ECU. I think you will need a schematic and look for a common power or earth.
I think you are getting closer to the solution. I'm seeing constantly low engine oil warning and low hydraulic oil warning. as well the inlet air temp high warning comes after running the machine for around 5 minutes.. Anyone has the wiring diagram please?
I will definetly clean the radiator this week. Thanks for the detailed explanation
Check your messages.
Thank you. I will try to understand this spider web first and see what I can do
Try first reading all the notes on Pages 1 & 2 before moving to the schematic. The document is hyperlinked so you can jump from physical to schematic component locations and back again. Then go to the schematic Page 10 and pay close attention to everything in the bottom RH corner, especially this table......
As usual, you are the best
My relay o one side of the post is ground and the other side is positive ,how does it send power to the heater element
Do you have a picture? Im guessing that when you say ground, you mean it’s connected to the intake? That is your intake (grid) heater element.
Ground is good on the heater intake ,I change my solenoid down by the master switch still have no power going to my air intake heater,what else could it be
also it shows on my dash screen intake heater is on when cold ,but still no power going to the air intake heater
A relay has at least 4 terminals. Which two are you talking about.? What machine model & Serial Number do you have.?
312D CAT 2012 model, solenoid has 4 post on it two are small and the other two are larger on each side.when cold intake heater kicks in on my dash screen ,I check for power and have power on two small post and one large post, but no power is going up to the air intake heater, check red wire on air intake heater can’t fine any breaks or corrsion on what else could it be
That doesn't help much. I see 30+ different flavours of 312D. Need a Serial Number to identify the correct electrical schematic, then we can start talking.
ok I will get the serial number,thanks
Power on both small posts could mean that you dont have a circuit to earth on the trigger wire to energise solenoid. A circuit diagram will help when you supply a S/N.
If both small wires are hooked up, disconnect them and turn the key on to see which wire is the signal wire for the heater relay. A meter will tell you that. Hook that one up to the relay, and run the other small one to a good ground with a small jumper wire. If the glow plugs come on you have a ground problem in the control circuit. Could be bad ground or bad harness. If the relay small wires are powered up and have a path to ground but still no transfer of power from the glow plug relay, The relay is probably junk if their was power to the inlet side of relay big wire connections. Simple check Simon C
I think cat might send the ground from the ecm to turn on the relay. That means there will be positive voltage on the other small wire all the time.
Thanks for the input,serial number is xkgkoo506. 312dl
I think it is a ground problem,the purple wire from solenoid ,I not sure where this goes to maybe the computer
Think I was off and what Mobile Tech has stated could be the actual problem. Probably is ECM controled. A schematic will better tell the story. Forgot about ECM control and was thinking more about signal grounding. Waiting to see the schematic. Simon C
Thank you for your information, very helpful.
I presume you mean XGK rather than KGK. Check your messages for an electrical schematic. Below a small section of the schematic. @Mobiltech is correct. The air intake heater is controlled by the engine ECM. With the engine coolant "cold" if you turn the key on you should have system voltage between the two 18SWG wires - 310-Purple and G850-Green. This is the coil side of the relay. I think this is working because of what you wrote already and the fact that the warning light on the panel illuminates. But even if the coil is working is it actually pulling the main contacts of the relay in.? When you power those two wires can you hear the reaya make a distinct "click" noise.? Batt+ comes to the intake heater relay via a 120A breaker on a 4SWG wire 108-Red. When the main relay contacts are pulled in by the coil the Batt+ goes out the the air intake heater on wire 877-Yellow. This is also a 4SWG wire.
This is very helpful,my wire blue and purple goes to my solenoid ,power on the blue ,no power on purple,do not here any click that you are referring to,where does the purple and blue wire go to
Are you testing for power between blue and purple with the key ON.?
Yes ,testing the solenoid at cold start, it not the relay install a new one and bench test the new one ,it got to be the purple wire or computer
Try testing for power between the purple wire and machine frame ground, then between the blue wire and machine frame ground. Come back with your results.
The blue wire has power on it when heating element is on ,the purple wire is dead when heating element is on. I hook a ground wire on the he purple wire and attach it to the frame turn key on and it did make my solenoid kick in ,but my dash screen kept sending me a signal saying service require. The heating gauge on my dash screen would come on for about 10 seconds or so then it would kick out and service require light would start flashing ,repeat the cycle and same thing would happen. I am not sure where the ecm computer is on this machine to check the purple wire. i don’t beleive it attach to the motor. Maybe you can tell me and I will check it out.
That makes no sense. Do you mean when the key is ON.? Check the continuity of the purple wire between the AIH relay and Pin 26 of Connector J1 on the Engine ECM in that case. You have the electrical schematic. The locations of all the components are shown on it. Go to Page 4 and click on the hyperlink marked 111 titled "ECM - Engine"
This illustration may also help. It's mounted right on the side of the engine block.
Can you measure the voltage of the batteries when you connect the purple wire to ground. I am wondering if either:- 1. The battery voltage is being pulled down too far (maybe caused by weak batteries) when the AIH is powered up that it is generating other Diagnostic Codes. 2. Codes are being created because you are grounding the AIH heater relay coil through the machine frame and not via the ECM which is the way it is supposed to work. One thing we have never touched on so far. Does the engine coolant temperature gauge on the dash panel in the cab indicate correctly.?
Good to know that jumping the return control circuit to ground instead of it going through the computer that turned it on originally will produce a fault code. I dont have the schematic but am guessing that it is similiar to the glow plug skid steer that was computer controlling the glow plug relay that you sent me the schematic on. Thanks for that tidbit. Simon C
For this particular 312D, oh yes you do..............
You are right again. I just checked and it was in my downloads, but I had not transfered it into my Cat Excavator Folder. Thanks for correcting me again.
Ok ,I will check this out computer is in a tough spot according to to this picture.i think it’s a break in the wire.
Maybe follow the schematic away from the computer on each wire to a plug 1 or 2 connectors downstream that is easier to get into and read pin numbers. If the power from the computer makes it that far, you know that section is good. If the returning ground does not make it that far then the problem is downstream further. It also give you a chance to check those plugs. With patience you will find it. Simon C