Big Ugly (my truck) has a new symptom.... Just had trans flush done and a new IDM
about 2500 miles ago just for filler. When driving the OD
light on the shifter starts flashing and it shifts erratically. It seems to upshift at low RPMs ~ 1400 and seemingly goes straight to TC
lock up. I have the flush done on schedule @~ 60k intervals. It had done this 3 or 4 times before and twice since the most recent flush. I first noticed it while traveling empty at highway speed on cruise control. C/C kicked off and I noticed the flashing OD
light, they have to be connected. I cannot force this to happen by cycling the OD
button, just seems to be erratic. My initial thought is something internal to the trans... pressure switch or something like that...
the only thing I know about tranny's is how to remove and replace.....
As always, any help or ideas please!
OH, and I towed a 5k travel trailer this weekend and it never happened, but I didn't use the C/C. It has happened on and off the C/C.
215K on the motor & ~ 150K on the trans. completely stock other than exhaust. (in my sig)