Volvo TAMD75 etc troubleshooting question

[SeaNile]

Looking at a boat with what's seems to be an honest own describes the following issue. Any idea of the possible problem? Could it be simple, an EDC replacement needed, transmission rebuild??

A few weeks ago I took the boat out and the starboard EDC (Volvo’s electronic transmission control) started to act up. Boat ran up to almost on plane, then went into neutral. Turned around and went back in. Starboard forward was disengaged. I only had reverse. This may be anything from a loose connection to possible needing a trans overhaul. I am almost certain it’s something electronic. I’ve dropped the prices considerably to move the boat on.

Thanks.

 

[Henry Boyd]

I would suggest you get a Volvo dealer to troubleshoot this issue. You may be better off resolving the problem than leaving it to a potential buyer. I know the early generation EVC electronics on our D6s are hard to find as I’m currently trying to upgrade our engine display. So I’d imagine getting components for out of production engines like the TAMD may be more problematic. Knowing what I now know about Volvo parts availability, I wouldn’t even look at your boat knowing there was an undiagnosed and unrepaired engine system problem.

 

[SeaNile]

Agree Henry. It's a boat I am considering that is significantly discounted due to the unresolved issue. Just wondering what the collective group here thought.

 

[dtfeld]

Just doing a quick search on Volvo EDC brings up numerous hits and its enlightening. From what I gather reading a few of these is that this is an integrated control system that controls the engine and transmissions electronically through an electronic throttle, to a "black box" that includes some "firmware". This in turn controls the engines and transmissions.

However, seems there are some basic electrical components that just like our Sea Rays need attention (switch contacts cleaned), or parts tested /replaced (sounds like throttles have a potentiometer to feed throttle position?). Seems there is also a "calibration" procedure for the throttles. The question can the problem be diagnosed accurately and is how much are the parts?

Behind all the gee whiz electronics is likely a very basic transmission with electrical solenoids or hydraulic actuator that controls clutch pressure, and they are not getting the correct signal or more likely no signal.

I think the guts of the transmission would be my last suspect as they are pretty robust short of serious mistreatment or hitting something.

If significantly discounted is enough to diagnose/repair the system, and everything else checks out, my guess is its fixable.