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So just tried to drop the tune in and I have a failed to load and a pulsing fuel pump!!!! Was just logging before I got home. Computer has a good battery running 4.4.4 editor resynced the mpv1 before I tried to write. And it failed right after erase??? I disconnect the batteries for a couple min and reconnect with the same thing happening.
Throw a battery charger on your truck, charge up the batteries, pull the fuel pump and abs pump fuses and relays and try flashing again AFTER batteries are charged up.
The 5.9?s are notorious for this happening if battery voltage levels are low enough especially since the 5.9?s cycle the ABS pump and fuel pump during the last 40% or so of a flash. Always drive the vehicle and warm it up, charging the batteries before flashing the ECM.
Thank you Jim! I had just taken it for a 15mile ride figured that would be enough. I am charging the batteries as we speak. They are at 98% truck is still warm. I'm gunna try it in about 30 min. Wish me luck!!
Ok all set!! Man that took some years off my life hahahahah. All the flashes I've done on other vehicles and those hold your breath moments!!! This one punched me!! Jim you are the man! Thank you. And the tune is pretty good. Truck needs less throttle to hold speed and when you lean into it it kicks you back pretty good! I will know MPG on Sunday as I have approximately 100 mile round trip. Thank you all you've taught me alot!!
A 15 mile drive should be plenty to get charge on the batteries for flashing but if your batteries are weak the cycling of the lift pump and abs pump will pull voltage down real quick and can screw up a flash. The 5.9?s it?s usually best to pull the fuses/relays for the lift pump and abs pump before flashing to keep them from cycling.Quote:
Originally Posted by Denaliquadrasteer
I can?t remember the exact number but I think it was 12.6 volts is the minimum battery voltage required to flash, if it drops less than that there?s a high chance it will fail to flash.
That's good to know! I was kinda confused being my batteries are only a year old. I will be doing some logging soon and some fine tuning. I will definitely be disconnecting the fuel pump and abs motor for the next flash! Thank you again Jim.