Having a major acceleration/ flat out keeping speed issue.. bare with me I tried to clean it up.
Here’s what I’m seeing/experiencing *When in EV mode and the auxiliary transmission pump is running, the truck drives normal under 25 mph with the engine off. (If commanding the aux pump OFF with my Snapon Solus+ the truck as predicted does not move) So I know it's functioning properly. The problem starts when the engine comes on, during acceleration, or once I’m above roughly 25 mph...at the same time the auxiliary transmission pump shuts off. (As it should)
At that point, the truck has almost no acceleration and may only reach 30 mph. The engine is working VERY hard to accelerate, almost like there’s something dragging or creating a huge amount of resistance.
There are no abnormal noises and NO codes current or stored in the engine, transmission, or hybrid modules.
It also has a heavy load idle you can hear in the exhaust tone randomly (engine runs great) transmission fluid is bright red and at properly level. Engine free revs no problem in park so not clogged cats
My current thought is a possible mechanical transmission pump failure? Since there doesn’t appear to be a PID for actual transmission line pressure, only the commanded pressure solenoid value...the only way I can think of confirming that would be to put a mechanical pressure gauge on it and see what the actual pressure is if the trans is even the issue to begin with..
The problem has slowly got worse. initially showed up when I hooked up my enclosed trailer. I immediately noticed that the truck had almost no power and wouldn't accelerate properly. Giving it a good amount of throttle just to maintain 40mph.
After that, I could drive it roughly 20miles, but eventually It would start experiencing the same lack of power and inability to maintain speed. From 70mph highway to 60 then 50..Eventually, it got bad enough that I couldn't make it 10miles. I had to have it towed home recently.
What really has me scratching my head is that when the truck is cold, it drives relatively normally briefly. The problem doesn't appear until it warms up, and then the lack of acceleration/speed becomes progressively worse until it basically won't move while the engine is running.
The combination of it driving normally in EV mode with the auxiliary pump running, but losing almost all ability to accelerate once the engine starts and the auxiliary pump shuts off, is what makes me suspect the mechanical transmission pump. has anyone experienced this problem? Or maybe better insight to whats is going on.
I'm an auto electrical technician for the last 20yrs and ive driven it for last 2years trouble free but this one has me searching for answers. Any help would be appreciated.
Here’s what I’m seeing/experiencing *When in EV mode and the auxiliary transmission pump is running, the truck drives normal under 25 mph with the engine off. (If commanding the aux pump OFF with my Snapon Solus+ the truck as predicted does not move) So I know it's functioning properly. The problem starts when the engine comes on, during acceleration, or once I’m above roughly 25 mph...at the same time the auxiliary transmission pump shuts off. (As it should)
At that point, the truck has almost no acceleration and may only reach 30 mph. The engine is working VERY hard to accelerate, almost like there’s something dragging or creating a huge amount of resistance.
There are no abnormal noises and NO codes current or stored in the engine, transmission, or hybrid modules.
It also has a heavy load idle you can hear in the exhaust tone randomly (engine runs great) transmission fluid is bright red and at properly level. Engine free revs no problem in park so not clogged cats
My current thought is a possible mechanical transmission pump failure? Since there doesn’t appear to be a PID for actual transmission line pressure, only the commanded pressure solenoid value...the only way I can think of confirming that would be to put a mechanical pressure gauge on it and see what the actual pressure is if the trans is even the issue to begin with..
The problem has slowly got worse. initially showed up when I hooked up my enclosed trailer. I immediately noticed that the truck had almost no power and wouldn't accelerate properly. Giving it a good amount of throttle just to maintain 40mph.
After that, I could drive it roughly 20miles, but eventually It would start experiencing the same lack of power and inability to maintain speed. From 70mph highway to 60 then 50..Eventually, it got bad enough that I couldn't make it 10miles. I had to have it towed home recently.
What really has me scratching my head is that when the truck is cold, it drives relatively normally briefly. The problem doesn't appear until it warms up, and then the lack of acceleration/speed becomes progressively worse until it basically won't move while the engine is running.
The combination of it driving normally in EV mode with the auxiliary pump running, but losing almost all ability to accelerate once the engine starts and the auxiliary pump shuts off, is what makes me suspect the mechanical transmission pump. has anyone experienced this problem? Or maybe better insight to whats is going on.
I'm an auto electrical technician for the last 20yrs and ive driven it for last 2years trouble free but this one has me searching for answers. Any help would be appreciated.
