Fordracer Posted July 22, 2008 Share Posted July 22, 2008 This might be a stupid question, how is load % calculated? I usually don't monitor it much since I don't know what it's telling me. I have a truck with an intermitent miss and surge. It had a code P0403 and a EBP sensor and connector recall. I replaced the nonresponding EGR valve and did the recall and test drove. I couldn't get it to act up. I was hopping the EBP sensor was causing the problem. The customer picks it up and drives it four miles and it acts up again. I install a VDR and have the shop foreman drive it and he couldn't get it to act up either. Give the truck back to the customer and he brings the VDR back with recordings a couple of days later. The only thing that looks strange on the recordings is the Load %. It's fluctuates from 0-10% 55 times every 10 seconds for 25 seconds. The ICP voltage doesn't fluctuate which is what I was suspecting the problem was. While I was looking at the recordings yesterday the customer pulls in with the truck acting up. We go for a drive and come to a stop and it surges and almost pushes us through the stop light. I replaced the IPR and connector and sent him on his way. I assume the Load % uses the ICP and other sensors to calculate it's reading but I can't find anywhere how it's done. I'd appreciate any input on how they come up with Load %. Quote Link to comment Share on other sites More sharing options...
Tony302600 Posted July 23, 2008 Share Posted July 23, 2008 i've been downthis road a bunch with hotline on all my weird weird concerns. They told me that load is calculated though "a lot" of sensors ranging from the tran's, to the engine, to the accel pedal. He didn't tell me exactly which ones, but said that they use load ALL the time when they mess with their trucks. Quote Link to comment Share on other sites More sharing options...
Fordracer Posted July 23, 2008 Author Share Posted July 23, 2008 If load is calculated from alot of sensors and the hotline uses it all the time on trucks they mess with what is it telling them that would help in diagnoses? On the truck I was working on the load% showed something was acting up but not what it was. The ICP voltage and pressure were staying steady. If it wasn't from previous experience I wouldn't of known it was the ICP. By the way, the customer came back today to say his truck runs great and that took care of it. Quote Link to comment Share on other sites More sharing options...
Keith Browning Posted July 24, 2008 Share Posted July 24, 2008 I did a little searching on this and came up completely empty handed. There is no mention of the Load parameter in any descriptive manner in the PCED and OBD descriptions. I do know of one use and that is it can indicate the condition of the injectors when all other diagnostics have found no root cause for a lack of power and hesitation. I have been looking at Load when using data logger lately just to get some sort of base line indication. I see normal readings between 10-30% at idle at varying temperatures. I had one vehicle that was showing 40% load at idle at operating temperature - FSE advised the injectors were degraded. We replaced them and the number dropped significantly. I asked and International FSM and quoted 44% as the max load when considering injector degradation. Good luck finding info on this. Quote Link to comment Share on other sites More sharing options...
Tony302600 Posted July 24, 2008 Share Posted July 24, 2008 I did a little searching on this and came up completely empty handed. There is no mention of the Load parameter in any descriptive manner in the PCED and OBD descriptions. I do know of one use and that is it can indicate the condition of the injectors when all other diagnostics have found no root cause for a lack of power and hesitation. I have been looking at Load when using data logger lately just to get some sort of base line indication. I see normal readings between 10-30% at idle at varying temperatures. I had one vehicle that was showing 40% load at idle at operating temperature - FSE advised the injectors were degraded. We replaced them and the number dropped significantly. I asked and International FSM and quoted 44% as the max load when considering injector degradation. Good luck finding info on this. U hit the nail on the head of that one. Quote Link to comment Share on other sites More sharing options...
Fordracer Posted July 24, 2008 Author Share Posted July 24, 2008 Thanks Tony and Keith. That gives me some insight on what to look for. I guess I'll have to watch the load more often to see what it does under different circumstances. I did think it was odd it was going down to 0% at idle and fluctuating so rapidly. I've always wondered what other pids are helpful that we don't use because we don't know what they are telling us. Quote Link to comment Share on other sites More sharing options...
cbriggs Posted July 30, 2008 Share Posted July 30, 2008 Not sure if its the same, but i was dealing with a gas truck a while back that wouldnt kick down, at wot full load , the load pid never broke 70%. After several calls to hotline i found an engineer that knew a fair bit about it. He stated it is a calculation based on rpm, maf, map and tp. Since a diesel has these sensors i think it would be close to the same, exept ebp and mfdes may come into play. Only the guy that writes the program knows for sure i guess. Quote Link to comment Share on other sites More sharing options...
Tony302600 Posted July 30, 2008 Share Posted July 30, 2008 True, and on the 6.0L the sensors from the trans also (what i was told) Quote Link to comment Share on other sites More sharing options...
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