Hey guys, I have a customer who owns a LandCruiser with a GM crate LS3 we installed last year, the trans is a 6L80 built/programmed by Zero Gravity performance. The truck has a few thousand miles on it and the customer is experiencing occasional long shifts, mostly 1-2 upshifts. He says the truck noses over in the middle of the shift for a long time then finally picks up again. He didn't seem to experience this at first but says it's growing in frequency and magnitude.
I had a shop near him drive it to see if they could recreate the event and catch it in a data log. They said it mostly ran great but were able to catch a long shift, the tech said it was noticeable and slower than previous shifts. He forwarded me the attached data file "8 1.hpl" which has that shift event recorded at the 5:15 time mark. You can see the system go into clutch control torque management and pull the spark back for about .5 seconds then ramp it back in and complete the shift. The overall shift time is .7s whereas other shifts in the log seem to be .3 - .4 seconds.
Jim at Zero Gravity is not much help, he says he can't remotely diagnose an intermittent issue and it's most likely just driver. My first inclination is to reset the adaptive learns and see if it goes away. After that, I'm not sure what else to look at, this same setup has worked fine in other trucks. Any suggestions would be appreciated!
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Originally Posted by Estep40511
