Hi guys, Having a problem with my D6n. Machine was working all day then @ end of day lights sputtered and shut down. I initially thought alternator but put 24v to machine and pulled codes. Main code is intake heater short to grounc. I took apart intake to make sure fins are still intact and noticed housing looks burnt. It seems the intake heater won't shut off. I checked continuity of the solenoid and I'm @ 22.1 ohms which is in good range. I also check the temp sensor and am @ 2.777ohms. Not sure what this sensors specs are. So my question is, does the temp sensor send a signal to solenoid to shut heater off? Also when I go to turn keey to off position everything stays on. I have to go to master disconnect or disconnect batteries to switch machine off. Is this a related problem or do I have a ignition gone too? Any help whatsoever is greatly appriciated!! Thanks in advance Rigger
Depending on your serial number, the AIH will be controlled by either the engine ECM or the powertrain ECM. The ECM decides when to turn on the AIH depending on temperature sensor inputs and the switch on the dash, so no, the AIH isn't directly controlled by the temp sensor. This isn't to say that an AIH fault isn't the cause of your problem, but I would probably start by troubleshooting your ignition issue. To get you started, the wires at the ignition switch are (based on a guess at your serial number); 101 red. Battery +24v 323 white. +24v when key is in off position 308 yellow. +24v when key is in run position 307 orange. +24v when key is in start position Do you have a turbo-timer fitted?
Hi, thanks for the reply, The serial # is ALY01931. I have a few codes that come up other then AIH but will list all. - 030-248.02 - INtake heater fault -030-819.02- monitor info incorrect -030-821.04 - monitor voltage low -036-172.04 - intake heater short to ground (this one was hard into monitor with serv code next to it -036-296.09 - engine ecm unable to communicate with/rt ECM 036-168.02 - inlet heater fault -113-168.04 - batt less then 18V CAT was saying a lot ofthese are from battery being drained. Why would my battery drain? Unless my alternator is fried as well!! WOW what a problem. I also was thinking ignition but then CAT said could be harness or connector so held on getting ignition till figure out what thsi is. As for a turbo timer I'm not sure I don't see any sensors going to/ around turbo. I get the service manulas tomorrow which will help termendously. Is it possible for the ignition to short causing glow plugs to stay on? When I hit power to it and turn key glow plugs don't turn off, Also all fuses and main relay are good. Ill post tomorrow on what I find out Thanks again Rigger
248.02 is for Cat data link erratic. Usually nothing to worry about. 172.04 is for intake air temperature sensor short to ground. Not your air intake heater. 036.168.02 is engine control. Voltage erratic. How do you know your AIH (glow plugs) is on all the time? Light on the dash or check with voltage tester? It's possible that the AIH relay is welded closed making the AIH on all the time. This could possibly drain the battery. What's the voltage at the battery with the engine stopped? and engine runing? A turbo timer is an aftermarket device to allow the engine to run for a few minutes after the ignition is turned off. You'd know if you had one, there'd be a small control box in the cab. Sometime they can go faulty and not let the engine shut down.
Hi thanks again, The glow plug light stays on but also the manifold is burnt a bit. Also took apart manifold to look @ fins becausae I guess this machine had an engine go do to fins breaking off and going into engine. So checked to make sure they were intact. And then turned key to power and they came on. When I was 1st looking into this had the power to it for 15 mins trying to diagnose it and the manifold was hot to touch. As soon as I stopped power to batteries manifold cooled down. The battery voltage is down I have a 7000$ booster system in my truck and put power to it that way to try and get machine started but can't even get it started. Leaving here shortly to get manuals then off to machine. I'm a couple hours in the bush so not like I got CAT right around me. Thanks Rigger
So why won't it start with a boost? Engine cranks but won't fire? Cranks slow? Nothing from the starter? Maybe the starter is faulty and draining the battery. Is it hot?
The engine won't even crank period. Turn key to acc then to start and nothing (which was a big surprise when I went to machine 1st time after died). I ended up getting tied up with somw cutting edges and services today but DID receive service manual book finaly. Going to start tomorrow morning with testing the ignition and starter. And from there move onto "engine temp sensor open/short circuit test" for code 036.172.04 After looking through and getting my pages bookmarked I'm not seeing anything that will stop my engine from cranking. Sucks that I have to knock off code by code. Its a 2.5hr return to cat for an ignition if that's pouched. Just to get it started to see if codes r still there. NEED a CAT computer lol Thanks again Rigger
This machine was running for atleast 11 hours before it shut down. If a starter was draining abttery wouldn't it shut down b4 11hrs?
Yes, you're right, but then, stranger things have happened. If you take into account what you know so far; Something apparently drained the batteries and caused the tractor to stop. We can be fairly sure of this with the logged fault codes for low voltage. (If you had ET, we could be very sure because we could find when the logged codes were set). Now the engine won't crank. I think the starter has got to be a suspect, but fortunatley you don't need ET to check this. I'm now leaning away from the ignition switch being a problem, because it seems that the ignition switch sends a signal to the engine ECM, and the ECM operates the starter relay. Good luck
sorry lost internet in camp, but had a few issues with machine. Starter was gone replaced that and got machine running, then noticed alternator was only charging when it wanted to. And batteries were fired. So replaced both those as well. CAT finally made it and test my display module was fried as well. Lol. I notcied glow plugs staying on again and my alternator wasn't charging. Tried to disconnect signal wires from AIH relay and noticed that solenoid was toast/corroaded so disconnected main power to it from starter and now alternator is charging and machine can work! Intown now to pick up relay which was a day away. Then to check if AIH is still all intact. Will post results when have em. Thanks Rigger
I have had the same problem on a excavator. Relay was stuck and the heater was constant on. Melted the heater and burned the turbo hoses off. Customer pulled upper hose and had flames coming out of intake! The heater had globbs of aluminum dripping off it. Replaced all that and never had another problem.
so the culprit was the AIH Relay, ending up frying whole starter system and alternator. machine is good and working! thanks for the HELP Greatly appreciated!! Rigger