Ok,
So once in a while my truck throws the U100 (lost comm. w/ ecm pcm). And some other sensors will throw a code when this happens. Truck never misses a beat, pulled and cleaned most connections etc. etc. Anyway... I already gave up on figuring out why this happens, here is my question for Mike L and other trans experts:
When it does this, it puts the truck in a mode somewhat like t/h. Higher shift points but it doesn't keep the tc locked on decel like t/h does. I thought I also read the trans raises line pressure to max... reason I ask this is that when this happens the truck does shift firmer/faster.
I didn't realize I had tripped this code today and after making changes to my tune I decided to do 1 WOT 2nd into 4th pull to make sure shifts and everything else felt good. The truck shifted firmer and faster than normal, and thats what caught my attention. It wasn't rough, or bad (feeling wise).. just firmer (like there was less defuel maybe?
)
Cleared the code, everything is normal, shifts like normal etc. Just curious what exactly the TCU does when it "thinks" it lost communication and puts the trans into this mode... looking for any info about why it shifts differently etc.
Thanks to anyone for your time who replies,
Todd
So once in a while my truck throws the U100 (lost comm. w/ ecm pcm). And some other sensors will throw a code when this happens. Truck never misses a beat, pulled and cleaned most connections etc. etc. Anyway... I already gave up on figuring out why this happens, here is my question for Mike L and other trans experts:
When it does this, it puts the truck in a mode somewhat like t/h. Higher shift points but it doesn't keep the tc locked on decel like t/h does. I thought I also read the trans raises line pressure to max... reason I ask this is that when this happens the truck does shift firmer/faster.
I didn't realize I had tripped this code today and after making changes to my tune I decided to do 1 WOT 2nd into 4th pull to make sure shifts and everything else felt good. The truck shifted firmer and faster than normal, and thats what caught my attention. It wasn't rough, or bad (feeling wise).. just firmer (like there was less defuel maybe?
)Cleared the code, everything is normal, shifts like normal etc. Just curious what exactly the TCU does when it "thinks" it lost communication and puts the trans into this mode... looking for any info about why it shifts differently etc.
Thanks to anyone for your time who replies,
Todd
