Tapping signals
AVIC-Z1 wants a few signals for your GPS Nav to work properly. It compares GPS data with Speed, Reverse, and Parking Brake. The first cable harness I connected was the adapter cable I received from Crutchfield. It translates most of the common signals from the Toyota radio connector into easier connections to the Pioneer cables/connectors.
You can see in one of the pics how I already started wiring it together. 12V+ Battery signal and 12V ACC (switched) and 12V Illumination, along with GND all needed to be crimped together. Speaker and Amp outputs were simple RCA jacks already attached to the Crutchfield adapter harness.
Removed the Glove Box. This first picture is not as revealing as I hoped, but shows how I tapped the Reverse and Speed Sense signals at a connector feeding the ECU behind the glove box. They are the pink and purple/white wires that were supplied by Pioneer. You get to the ECU by removing the glove box (2 screws and 2 door stops), and the black plastic ECU cover (3 screws). Change your cabin air filters (if you have them) while you are in the area.
It's the 4th connector down on the ECU. I had read a lot of advice about tapping Reverse from the back-up light harness far away in the taillight housing. I chose instead to tap Reverse signal from the Transmission Position Reverse signal, which I think is an input to the ECU. No harm done so far. YMMV. I referred to the FSM to confirm which wires were which.
The center console trim panel around the shift levers is also held in place entirely by tension clips. The Hi/Lo TCase shift knob just unscrews and comes off. Removing this trim made it easier for me to route the iPod module later into the arm rest storage console. I spent a lot of time cleaning out dirt, dust and gunk under here. Notice the rust? Looks like Wifey might have dumped a drink or two.
I actually DO NOT recommend tapping the P-brake switch signal here, as there is very little accessible P-brake switch wire to work with. I should have tapped the P-brake wire at the cable bundle in the driver's door channel. Or should have removed the driver's seat and caught it coming out from under the console. It was a reddish w/black striped wire I found later in the driver's footwell. In the pic here, I just Grounded it for test purposes. That is NOT recommended for normal operation.