High Idle or bad torque convertor...AM6 Auto Tranny

[AlvinCitroenC5]

Hi,

A number of mechanics that have taken a look at my 2005 Citroen C5 II 3.0 V6 with the AM6 automatic (I have to drive far to a Sonnax automatic transmission specialist, which I have not yet gone to) cannot nail down as to why my car while in D while holding the brake down at the stop light really wants to pull forward. What I am trying to say it seems that the torque convertor really wants to pull the car forward, and as I hold the brake down to keep the car still, the engine's vibration can be felt within the cabin. Please see my idle speed within the posted photo.

I have read the AM6 transmission online was designed to go into neutral to save fuel when at idle. Is this true for the AM6 when applied to Citroens? Because if so, then this feature is obviously not working in my car. Can someone shed some light as what I should do? I have already change the fluid, which the shifts are much smoother than before, but this idle / stall speed issue is still having this issue.

Thanks.