Hello i just replace my original audio system with Pioneer SPH DA120. it was a big mistake make a long story short... i cant use the wheel right control buttons , the guy in the workshop told me to buy a harness to fix it any ideas? thank you in advance Kfir
^^^ Yep, most aftermarket HU's require a interface adapter for the steering wheel controls. Whoever sold you the unit should have made that clear.
i cant control the speedometer or anything from the steering wheel, any ideas? only when we connect the harness to the original audio system its works thanks
See Post#2 & #3. It can not be stated any simpler: you need an adapter harness to regain your steering wheel controls. Do you understad? If not, reconect the OEM radio and sell the Pioneer headunit on eBay/Craigslist.
The OP is talking about a Gen 3 Prius. In Gen 3, only the round switchpad on the left side of the steering wheel has to do with audio. The round switchpad on the right is for multi-info-display modes and HVAC control, and is not wired through the audio equipment (ok, at least not in my 2010, I presume still not in the later model Gen 3s). If the OP is talking about the switchpad on the right not working, that seems a bit puzzling. I don't have wiring diagram access at the moment (techinfo subscription ran out), but IIRC it is wholly independent of the audio unit, and perhaps there is some simple mistake behind it not working. -Chap
Take a look at the grounding of the TRIP/DISP switch circuit—the pink wiring in the lower right, here. You can see there are two alternative paths, one with the notes (*8, *9) and the other noted (*12), where the notes are explained up at the top. If your original audio system, the one you replaced, was the plain "Radio Receiver Assembly" (no fancy display, just the lines of LCD text), then the switch grounding follows the (*12) path, straight to the L85 junction connector and to ground. But if your original system was the "Navigation Receiver Assembly" (*8) or the "Radio & Display Receiver Assembly" (*9), then the ground path for the switches went to one of the terminals at the headunit, and depended on that connection for grounding. So I am guessing you originally had *8 or *9, and however you hooked up the Pioneer unit, that pink wire from your original connector is now hanging in midair and your steering switches have no ground. It looks like you wouldn't go wrong by just grounding it (but it's your car so I won't be hurt if you want to think it over yourself). Off topic, but it's kind of interesting how they change things up also based on whether your model has the "touch tracer" display (pictures of the steering buttons show up over the speedo when you touch them). Without the fancy display (*7), the TRIP and DISP buttons are just simple switches wired straight to the combo meter (AU2 and AU1). With the display (*6), so they wouldn't need to run extra circuits through the spiral cable, they put a microcomputer in the steering wheel, replace AU2 with an IG power source for the computer, and replace AU1 with a single STRG wire where the computer transmits codes for what buttons you're touching or pressing. Clever.... Either way, it won't work if the ground's not connected.... -Chap
