Cat 329E Ser. No. PLW01440 Six occurances of first level engine coolant overheat - at 228F, and two at second level of 232F. Hooked up ET to get codes - don't have code for cab monitor to view them. Parts book shows coolant temp sender on to front of engine, SIS shows one of left side and one at rear top. Which is right? Machine does not appear to be running hot otherwise. First day used, by excellent fast hoe hand didn't overheat. Second, third, and yesterday threw warning on several times eventhough it's been like ten degrees cooler than the first day. ET also shows code: 1250.5 Remote Communication Module - current below normal, is this the software in the Dell laptop related. Thank all of you so much for sharing all your knowledge. Richard Beard
There are 2 identical Part Number of sensor, one is for the inlet manifold air temperature, the other for the coolant temperature. See the 2 diagrams below. Try exchanging sensors 4 & 4A just to rule out a sensor problem. Do you have an infra-red heat gun that you could use to double check the coolant temperature on the hose coming out of the thermostat housing to the radiator..? Regarding your CID 1250 FMI05 Diagnostic Code this relates to the Cat Product Link/Vision Link software that transmits fault codes wirelessly from the machine ECMs to the local dealer. The machine sounds pretty new so why not ask your dealer if there are any updates..? What I can't understand is the "normal" Failure Mode of this component is FMI 09 (Abnormal update Rate) rather than FMI 05 (current below normal).
Thanks Nigel, by the time I got the ET hooked up and got the codes on-site they were not using the machine, but the alarm was going off and on - and the attendant temperature on the monitor was between 223 and 229 - up and down. I had the IR heat gun on my truck but considering the time issue and the fact that the operator was pushing with the D6T and just didn't have time to check. I will do the sensor switch, and verify temp of coolant out of thermo. housing on Monday. I sure was glad to see that the 1250.5 was not an ecm related issue to the coolant temp. I will check with Empire - our Cat dealer for updates. You folks are very professional and awsome. Thank you. I'll close when I get this fixed. Richard Beard
That's newer machine than what I usually get to poke my nose in. What I have seen on C and D models is the plastic coolant reservoirs have coolant at the proper level but the radiators were way low on coolant. The culprit is the crappy radiator cap that won't hold any pressure. A little air gets in the system and the coolant won't be drawn out of the reservoir which is usually mounted below the radiator. The abnormal update rate can make sense with the low coolant level if the thermostat is only partially covered. The flow is restricted until the stat opens and the coolant hits the hot areas of the head and the near steam heat hits the sensor. Since it doesn't make sense to the computer that the coolant could get hot that fast it pops a code. The moral of the story is to never ever rely on the level in the reservoir. Alway pull the cap before start up and make sure the radiator is full. You might also check the radiator caps with a tester. If it is bad get a new one from Napa. The OEM cap is garbage.
John, thank you for your help! I was like 30 miles from the site when this happened. I asked the operator to cool the machine down - and safely remove the radiator cap. He called back and said the radiator was completely full. I'll call the mechanic/service person tomorrow at 0500 and ask him to do the same thing when the machine's cold and be sure the radiator is completely full. You are so right, many good engines have been damaged from the reservoir being full and the radiator low, and like you said a defective cap will not seal and allow the lower pressure in the radiator, when the machine's cooling down to draw the coolant in from the res. I really smiled on the comment on the cap as so many OEM parts are lower quality than a few years ago - cheapest supplier! I will advise what the service mechanic finds tomorrow morning. I do so appreciate you personal help. Kindest regards, Richard Beard
John & Nigel: Thank you both for helping. Found rad. cap on overflow reservoir loose. I couldn't find cooling temp. sensor section in our on-line SIS account. Installed new sensor - less than fifty dollars. Code gone and temp. where it should be. Checked machine cold before startup and sensor on Operator's monitor showed 237 and before removing old sensor hooked-up new sensor - it read 49 degrees on cold morning here in SW Arizona. Thank you all. What a fine website!
It's always good to get feedback on the solution to problems. Glad it worked out for you. I've seen sensors before throwing Fault Codes on oil systems like hydraulics but when you put the same "defective" sensor in a cooling system with lower temperatures it would work fine. Go figure.
Nice work and thanks for putting the solution in the memory banks here.