Blinking light between Drive and 4th gear on a 986 Tiptronic

[Malty123]

Originally Posted by Lil bastard

The lights flashing as you describe indicate a fault in the tranny. The coolant shut-off valve is operated electrically, so your fault may be as simple as a blown fuse - check the fuse panel for the appropriate fuse. It could also of course be a faulty shut-off valve. This can be checked by jumping the pins appropriately in the trunk control box - this procedure must be done in order to flush the cooling system. If the valve opens when jumped, it's working properly.

Another somewhat common cause of this fault is a dirty switch at the tranny. This gets exposed to mud, water, dirt and can become inoperable - usually accompanied by an inability to operate the tranny in manual mode. You can pull the switch and clean it up, fairly simple DIY.

Cheers!

Ive got the same flashing D and 4 lights, Where is this tranny switch located to check it?

And which pins need shorting to operate the coolant valve to check that?

Thanks

[tonythetiger]

I will revive this thread rather then start a new one.
2002 tip, 986 S with 80K

Flashing 4th and D after warm up, however transmission works fine and the normal lights come back in a minute or so, go to 4th and D again, etc as I drive. Automatic and manual function fine, just dont get the feedback in the dash lights when its out.

I have heard this could be the transmission’s coolant vacuum valve. Does this circulate coolant through the transmission? That seems to be the simple fix and makes sense.

I had the transmission serviced, new fluid, filter etc about 6 months ago, but the problem didn't completely resolve. Now with the warmer weather, I'm thinking I should iron out this issue.
I have a durametric scanner, but it only shows alarm fault codes (historic, none present now) to be honest, I am not sure I'm using the durametric to its potential, it seems pretty lame when I do the short test on all modules, so I would welcome advice on this as well.