Keith Browning Posted February 18, 2010 Share Posted February 18, 2010 Any of you gents remember what temperature the 6.4L derates power? It isn't published and I cant find my notes from the classroom... I know I wrote that down. Quote Link to comment Share on other sites More sharing options...
mchan68 Posted February 18, 2010 Share Posted February 18, 2010 Do you mean FRT (Fuel Rail Temperature)? Quote Link to comment Share on other sites More sharing options...
Keith Browning Posted February 18, 2010 Author Share Posted February 18, 2010 No, engine temperature... BUT NOW THAT YOU MENTION IT I am not sure because fuel temperature sounds familiar too. We were given a number in training was hoping I was not the only one who wrote it down. I am sure I will find it eventually. Cooling Protection Strategy The cooling protection strategy is activated by the PCM only in the event that a significant overheating condition has been identified. The ECT and EOT sensors are used as input sensors to determine if the engine is overheating. In the event the PCM has activated the cooling protection strategy, the PCM will then start to derate the engine torque and limit fuel to the engine. When the cooling protection strategy is activated the temperature gauge will indicate the engine is overheating. This strategy provides engine temperature control when the engine coolant temperature exceeds certain limits. A cooling system failure such as low coolant or coolant loss could cause an overheating condition. As a result, damage to major engine components could occur. If the overheating condition continues and a critical temperature is reached, all fuel injectors are turned off and the engine is disabled. Quote Link to comment Share on other sites More sharing options...
Bruce Amacker Posted February 18, 2010 Share Posted February 18, 2010 From my notes: The ECM will de-rate the engine (reduce power) if the fuel temperature sensor (FTS) reads 194ºF or higher. The PCM may also derate if the ECT or other temps get out of range. The ECM: Energizes the electric coolant pump at 77 degrees fuel temp Turns it off at 68 degrees Increases fan clutch command at 151 degrees Derates engine at 194 degrees (fuel temp) (reduces fuel delivery to match cooling system performance) It is odd what triggers the truck into “derate” mode. For example: Exhaust temp is too high EGT open circuit EGRT sensor open circuit Low fuel pressure EOT exceeds 275 Oddly enough, if it is overheating it will keep running until it burns up! The radiator supplier was having some problems and a few bad radiators made it to the assembly line, which were replaced after the trucks were sold. One particular truck had a problem after the radiator was replaced: After having the system emptied and refilled, the truck was driven several times and the coolant was topped off. The customer complained of an intermittent lack of power since the radiator was installed. The tech graphed out CTS, EOT, and fuel temp and went for a ride. The FT was cycling up and down to the point of fuel derate. Realizing that the main radiator was recently replaced, the tech put a vacuum bleeder on the degas bottle and pulled a vacuum on the system, and was able to get over a gallon more coolant in the tank! After properly bleeding the cooling system, the performance problem was fixed. The problem was the engine reaching derate temperature and the PCM cutting back the fuel command. Rotunda 078-00497 (This isn't making 100% sense. I wonder if the tech also bled the secondary cooling system....) 20922 - 2008-2010 F-SUPER DUTY – Radiator coolant leaks and PCM derate strategy due to hyperextended thermostats. Some 2008-2010 SuperDuties with 6.4 engines may exhibit a lack of power without DTC’s high temperature gauge readings and reduced engine performance (PCM derate strategy designed for engine temperature protection) due to bad thermostats. Diagnose these by monitoring EOT and ECT. With the EOT at 195F drive the vehicle unloaded at 55-70MPH at a steady state while observing temperatures. If EOT is less than 8 degrees higher than ECT, and the coolant temp fluctuates approximately 5 degrees, the thermostats are functioning properly. Only replace the thermostats if the EOT exceeds ECT by greater than 8 degrees or if the ECT readings fluctuate 10-12 degrees every 30 seconds. Effective date 7-30-2009 Good Luck! Quote Link to comment Share on other sites More sharing options...
Aaron Posted February 18, 2010 Share Posted February 18, 2010 Should also to be of note, that EOT is significantly higher than ECT with the grille cover installed, as well in regeneration the ECT/EOT spread goes through the fucking ROOF. Quote Link to comment Share on other sites More sharing options...
rlchv70 Posted February 18, 2010 Share Posted February 18, 2010 I believe it is 245F. Quote Link to comment Share on other sites More sharing options...
kevin41 Posted February 18, 2010 Share Posted February 18, 2010 just received this inf from hotline pcm will go into power derate when ect exceeds 235f eot exceeds 258f frt exceeds 194f egrta exceeds 1310f then was told to make sure egt12 does not exceed 1500f and egt13 does not exceed 1700f not sure if last two temps will cause derate. Quote Link to comment Share on other sites More sharing options...
Aaron Posted February 18, 2010 Share Posted February 18, 2010 Thank you sir. Quote Link to comment Share on other sites More sharing options...
Keith Browning Posted February 19, 2010 Author Share Posted February 19, 2010 Ahhh! The info I was lookin for and much much more. Thank you all! Quote Link to comment Share on other sites More sharing options...
rlchv70 Posted February 19, 2010 Share Posted February 19, 2010 just received this inf from hotline pcm will go into power derate when ect exceeds 235f eot exceeds 258f frt exceeds 194f egrta exceeds 1310f then was told to make sure egt12 does not exceed 1500f and egt13 does not exceed 1700f not sure if last two temps will cause derate. No offense, but I believe some of these values are low. EGRTA should be able to go up to 1380F before derate. Quote Link to comment Share on other sites More sharing options...
Bruce Amacker Posted February 19, 2010 Share Posted February 19, 2010 There's been some changes, obviously. The numbers I have written from class do not match what everyone else has. Most likely programming (flash level) changes.... Quote Link to comment Share on other sites More sharing options...
robp823 Posted April 1, 2010 Share Posted April 1, 2010 none the less great info thank you. Quote Link to comment Share on other sites More sharing options...
Aaron Posted April 2, 2010 Share Posted April 2, 2010 Thing is, there's no messages for the EGRTA de-rate... Truck will lose speed, I had one doing this and it was really difficult to duplicate the concern, and the truck eventually finally set a P040D pointing me in that direction. It would be handy if it threw a little message up on the IC that said "Vehicle over temperature, limited engine power" while it was in de-rate so at least the customer could have some feedback or maybe know that this is a normal condition. Obviously this could be ignored during regeneration, or at least have a little higher threshold for the message being displayed... Kinda like if EGRTA > 1310 for >3-5 seconds display message. Since the truck de-rates at that temp anyway, it should only show up if it sees that over temp a couple times in a row, or if it sees it stay hot, like the commanded de-rate isn't working. Hard accel a truck in regeneration and watch EGRTA and you can actually see/feel the truck de-rate when the EGT gets up that high. Quote Link to comment Share on other sites More sharing options...
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