Quote:
Originally Posted by HPsauce
But remind me how it behaved. I recall you said the reversing light was on (not a surprise, separate circuit) but had it selected Reverse gear, or not until indicated on the display and the TCU commanded the valve body?
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It wouldn't select R unless the shifter was held in between P and R in an extremely precise position (within a mm or two). I think the necessary sprung contact was only making a connection right on the edge of the base contact, so any movement either way and it failed and dropped out of gear. R on the cluster was coincident with it being in gear, which makes sense as the TCU will send it a CAN message.
Having cleaned it up and put it back in, I was checking the shifter alignment yesterday using VCDS. Between P & R and R & N the TCU shows 'Z1' and between N and D it shows 'Z2' so those intermediate contacts definitely tell it something different. Presumably its so it can prepare for what is coming next - it apparently can't tell direction, since it can be put in to Z2 from D, and then put straight back in D, but I guess it uses the Z positions to prepare the gearbox for what may come next.
I didn't get the binary code for Z, but that can probably be worked out from the contacts, or observing VCDS again.