Weak FM radio reception in 2010 Prius?

I really hope that TSB soon comes and it will apply also for my stock CD reader + radio here in EU...

 

bumping with anticipation
xo
a pkg II owner

 

There is a TSB on this issue.
I have to have mine done. There is a VIN sequence( build date) that are effected by this.
Mine does qualify.
Good luck.

 

Are you sure there is a TSB on this issue, I thought it was coming soon. Also try this find a spot where the signal fads out and turn off the car then start it accessory mode and see if the signal is now clear. Mine is perfect when the car is off.

 

There has been a TSB for US JBL radio models. Some have reported in this thread that it has not changed anything.
Another TSB for the non-JBL CD-reader-only model was announced on this thread a few posts back, but no update since on its release.
I am still with a radio that does not manage to reproduce FM radio stations clearly in any situation...

 

Of anyone has access to/ or knows the TSB number for the non-JBL fix, please please let us know

 

I'm going to hazard a guess here. There is a feature build into lots of radios these days called diversity tuning where there are actually 2 antennas and the FM radio constantly monitors which is receiving the stronger signal and switches between them. I'm wondering if any of you have looked at the head and noticed an unused input near the FM antenna input. It'd be just like Toyota after all the shennanigans they have pulled with the audio/nav system to only hook up one of the inputs.

 

Does anyone know if you can change and std radio for JBL. ???

 

It really is hard to believe that this ridiculous problem hasn't been conclusively fixed as of yet. It's 2010 Toyota! (almost 2011!)

 

You have to remember that a radio is not a new technology, its only been around 100 years. I have had this problem since June the day I bought the car. I have had calls, emails, one says they are working on a fix the other one says they don't have a problem with the radio. I tell you and I am sure people just say its just the radio but I paid for it and I want it work, I will not be buying another Toyota. Think about it if this was something serious and you get this run around, they really aren't concerned about the customer.

 

I know that this is a long thread, but if you'd read it you'd have seen that there's been a great deal of work done by forum members to ascertain what the radio is and what the probable causes of the poor FM reception are. It's not a diversity system, it has a single antenna with a built in, separately powered antenna amplifier (there's lot's of debate in this thread on that topic, too). Some have reported that changing the antenna helped, my experience was it made no difference at all. Changing the radio for an after market unit helped a little, but only in as much as the interference was less objectionable, the reception is still poor in weak signal areas. Most have noticed that the reception improves if you stop the car and improves a great deal further if, when stopped, you switch from "ready" mode to "accessory" mode. In my own case I can stop in an area where the signal is breaking up all the time and the fluctuating noise stops, leaving just an elevated background noise level on the signal. Switching the car to accessory mode significantly reduces the background noise level, pretty much proving the point that something in the cars main power system is interfering with radio reception. My personal view is that the cars electronic systems (most probably the power electronics) generate sufficient electrical interference to raise the noise floor enough that weak FM stations are subject to noise and poor reception. I doubt there's much Toyota can do to fix the problem and it's unlikely that they will own up to it as the cost of any fix (if it is EMI) may well be prohibitively expensive or impractical to implement on an existing car. Jeremy

 

Sorry for the inconvenience. In the future I'll make sure that I read every word of every thread before I post a comment or ask a question even if they are 50 pages long. I hereby stand reprimanded.

 

I wouldn't worry about it. There's so much disinformation on this thread from self-appointed "experts," that it's pretty worthless for information anyway. The fact is the rear windshield has a second antenna that could be used for diversity reception built into it; whether it's hooked to anything is a matter of some conjecture. It's also a fact that there is Toyota literature extant that refers to the Gen II and III radios as being "diversity" capable.

The noise that people mislabel "static" is, in fact, FM multipath distortion, which is alleviated with a good diversity design and execution. It's extremely unlikely that vehicle electronics are causing interference to the FM broadcast band; any RF engineer should know this, as FM, by definition, is not very susceptible to RF interference. But, that's another discussion.

Some useful things people could do: someone who has had their car apart might verify if the rear glass FM antenna has leads coming from it, or if it even has connectors for leads; someone who really knows the radios themselves could dissect the lead harnesses and figure out what goes where; Toyota could step in and definitively speak about what radios in what cars have this mysterious "diversity" capability, how it is executed, etc.

I suspect what will continue to happen is more misinformation, disinformation, and non-communication from Toyota, as it's easier (and far cheaper) to ignore a problem and put it off to "noise interference" or "unknown causes" than to actually fix it.

 

I had a rear rear door disassembled many times and there is no antenna wiring, but the power cabling for the defrozer only.

 

I have had my rear hatch apart too, to fit the reversing camera and can confirm that there's no antenna in the rear glass.

I can also confirm that the standard JBL head unit (non-nav) only has a single antenna connection so cannot be capable of diversity reception. There are several photos on this forum that show the rear of standard head units, so you can confirm this easily enough.

As a retired EE with lots of RF experience, I can confirm that the 'chuffing' noise whilst moving IS multipath, but that the noise whilst stationary, that goes away when you turn off the car's power systems IS NOT multipath. It can't be, as the multipath noise is caused by periodic reinforcement/cancellation as the vehicle moves though multiple RF fields, some direct, some reflected. As FM receivers effectively phase lock to the strongest signal, the interference seems to be the receiver losing lock and regaining it whilst the vehicle is moving. This effect stops if you stop the car, but the high background noise still remains until you switch the car's power systems off by going to 'accessory' mode.

Done this and we've confirmed there's no rear screen antenna and we've dissected the harnesses and worked out what every wire does.

No argument there, it's what they've been doing since the problem was first reported.

Sorry if my post re-the non-existent diversity system sounded a bit terse, it's just that seeing the same question get raised time and time again does get a bit wearing to those of us who've been struggling with this defect for a fair time. Jeremy

 

There is an exiting TSB to address this issue: T-SB-207-10, Rev 1 issued 7/29/10, "Some 2010 model year Prius vehicles may exhibit poor FM radio reception. A radio with updated tuning has been developed to improve this condition". After they replaced the radio, reception was marginally improved - not as good as other cars, but better than it was. Of course, before I was aware of this TSB I was told that "they all do that", and that there "was no problem" by both my dealership, the Toyota field rep, and Toyota corporate. Sound familiar?

 

Well, I'm sorry to say you are incorrect. There IS an antenna in the glass, whether it's hooked up or not is another issue. This is the kind of "authoritative" post I see here all the time that is doing more harm than good, imo. Please provide cites for all the "facts" you quote. Simply asserting something does not make it so.

You didn't even bother addressing the numerous references in Toyota literature to the "diversity receiver."

Not much help.

 

The TSB only addresses the JBL radio. The standard basic radio for level II trim has the multipath problem, as well.

Maybe we should split this thread, as it is apparent people are confused, and talking about apples and oranges.

Forgot to mention the previous poster also is reporting some kind of noise I've never experienced (when the car is not moving, and alleviated by turning off electric systems). I have only experienced multipath distortion in my II.

Edit: Just noticed, he's in the UK, for goodnessssakes.... No telling what equipment differences there are. We need a separate thread, methinks...

 

Downrange,
Can you please cite the antenna in hatch glass info

 

Here's a quick search for cite results:

2010 Toyota Prius 5DR Sedan CVT Hybrid For Sale | Bloomington MN

Toyota Prius, East Swanzey, NH, Hatchback, Toyota of Keene Stock: T0276 New Hampshire, Swanzey, Peterborough, Brattleboro, Vermont

There are literally dozens of references to the "diversity antenna" on the Priuses. Location: seems to be the top of the rear window, but as said, haven't seen one apart. There is a separate grid of wire there that only goes half way across the glass, but is it hooked to anything?

I can't understand why there isn't a detailed manual for the base radio somewhere that explains all this in clear language.