Trans problem

[andiyaco]

I have a isuzu mu 4 door auto 3100cc auto whats happening is when its idleing the check trans light flushs and as soon at u touch the gas pedal it goes away until the car goes back to idle rpm car drives fine no issues also when selected 2wd the 4ws light stays on but when on hoist it selecting 4wd and 2wd just the light function

[geeves]

first thought is low fluid level. Second blocked filter ion auto. When was it last serviced and what colour is the fluid

[andiyaco]

Fluid was real bad drian the whole lot and put a new filter

[geeves]

before or after?
Could be a blockage in the valve body as well. Its probably fair to say that if you ask about it you shouldnt be touching that.