CAN is the new protocol (replacement to serial bus communication) which I believe is used on the 2008+ GM vehicles.



If you want it (was not available when I bought mine), go for it. The module with CAN-D will work for the older serial bus communication vehicles as well.

 

Gotcha, thanks. It would seem to make sense then to buy with CAN-D ... if I'm going to start investing in GM-centric tools, I might end up buying a newer GM sooner than later ...

 

ok, looks like the vacuum switch near the firewall is shot, and the fitting that goes from narrow vacuum to the actuator is shot.

anybody have part numbers or official names I can take with me to Advance Auto?

 

"narrow vacuum"? Not sure what you are describing with that statement.

As far as the electric vacuum switch is concerned, I have never heard, nor seen a definitive name for it. I have not been able to find it on any aftermarket sites either.

 

the vacuum coming off of the switch is pretty narrow. the nipple going into the actuator is wider. there was a plastic fitting that was stepping up from the narrow vacuum line to the wide input nipple that broke when I tried to remove it from the old hose.

I ended up using a standard male-male vacuum connector to step up to a wider vacuum tube, which was right for the narrow line, but a little soft for the wider tube. I wrapped it in electrical, we'll see if that does the trick.

as far as the switch, yeah, advanced auto couldn't figure out what I was talking about, and unfortunately the nearest dealership parts counter closed at 1, won't re-open 'till Monday. is this sounding like a dealer-only part?

thanks for all your input.

 

also, this isn't a vacuum solenoid, is it?

 

deleteme.

 

Yes it is, just not in the traditional sense of being vacuum powered.

I did see some information over at another site, but it was centered around the mechanical vacuum switch at the transfer case. One part number that was listed (89059420) is the electrical switch which tells the TCCM that the axle is engaged. If you need to replace this switch, I would contact the dealer. Would not want to see you buy the improper part.

 

yeah, i came across that too. the pic is what I'm looking for the two vacuum prong, single electrical connection switch. The one that sits on the firewall:

http://www.automotiveforums.com/vbul...mp;postcount=6

89059420 is the cylindrical switch that actually sits on the transfer case itself, right?

 

89059420 is actually the switch that is on the front axle down where the engagement cable enters. When the front axle is engaged, this switch is closed, telling the TCCM that the front axle is engaged.

And yeah, that is the vacuum solenoid looks like.