Weak FM radio reception in 2010 Prius?

Don't know if you guys read any of my findings and my post earlier, please read. I have DAB (Digital Radio instealled) and the same problem presists so it can't be the stock radio is faulty.

You guys keep talking about the stock radio but even with DAB radio installed on my car, you will find the serverity of the whole problem because DAB radio enhances the problem.

Initially to solve the radio problem I had DAB installed thinking that will solve the problem, if the stock radio is badly made, then the DAB £450 ($900) toyota parts will solve the problem but I was wrong.

Now with Map Lights & DAB on at the same time I will lose signal competely (so if the door is opened I will hear nothing), and with stock radio I will get the hiss, I can duplicate this 100% of the time. I also lose signal when I turn my headlights on for DAB and the stock radio will have noise and that also can be 100% duplicated.

I just think that DAB actually enhances the problem and it has made me realize it is the entire HU problem and not just the radio.

So to save you guys a bit of time trying to discuss about stock radio which I appreciate but please read other posts so you can pin point the problem better.

 

Actually, I don't think it's the radio. My suspicion is the amplifier in the antenna. Did you see the post where the fella discovered that the replacement radio didn't power up the antenna amplifier? He had to stick 12V on the thing, but, when he did, the noise... went away.

KBeck

 

I you dig, you will find that other HUs function fine - in my case, much better than our Lexus and Nissan Xterra.

They are just data points, but I think there are quite a few showing that with the existing antenna/amp - and with no modifications, other HUs get better reception.

 

A good observation, and one that brings us back to the root cause. At the end of the day it doesn't matter too much what the exact cause is, as long as it can be fixed. If changing the head unit fixes it, then that tells me that the root cause is in the head unit, probably in the front end design (either excessive SNR, poor inter mod/cross mod performance, or some other failing).

The only anomaly remaining is the DAB one, because the DAB receiver uses a separate antenna and front end, it just routes audio into the head unit, plus has some control signals coming from the head unit. I'd considered getting the DAB option, but at £470 (over $700) it's an expensive doo dad, particularly if it doesn't fix the radio problem. I've heard a report from the UK Prius group that the DAB option works well on the GIII, though, so I wonder if poor performance may be an installation issue? I can't help but wonder about that stick-on DAB windscreen antenna; my experience with screen antennas over the years doesn't fill me with confidence that it would work well.

As I've mentioned above, I'd consider switching head units if there is a good chance that it might fix the problem. The major issue I can see with doing this on my T4 (roughly equivalent to a US package III, I think) is the JBL sound system, which looks to be tricky to interface with.

Jeremy

 

PAC has a simple $50 'interface' for the base amplifier JBL system. With so many great deals on HUs, I'd go that route.

 

Thanks for that, I go and take a look at it and see if I can get one over here.

I'll admit that I'm tempted by the head unit you fitted, the Chinese (aren't they all?) one. Two good reasons, apart from the radio performance, for going down that route are the neat fit into the Toyota OEM fascia and the ability to change the nav software to something like TomTom, with a really good user interface (I hated the Toyota nav when I had an extended test drive).

It'd be nice if Toyota at least acknowledged the head unit problem, though.............

Jeremy

 

They don't even want to achknowledge the problem with their brakes which was only a software update which really cost them nothing. But with the HU I think it can't be fixed by a software update it is a component replacement or completely redesign. It will cost them so much money they will cry.

I will get the HU changed and then I will let you guys know if it solved any problems or not.

 

Actually Jeremy Harris since you are in the UK you must have heard Nissan's advert on the Radio. It saddens me. Because the ad goes something like this "If you have a 7 year or older car which rattles and has a shody radio then exchange it with a new Nissan", well I believe our Pirus has both of those problems. It really pisses me off.

 

Just a small comment: Nobody heard and saw production Nissan Leaf yet.

 

Yes - and running random ideas and theories on chipsets that are not even defined (on the given units) - I like the effort! In the big scheme of things, we can look at many ideas - PLL (one of which) - but all cars are unique...

 

Out of interest, has anyone actually had the FM radio problem fixed by Toyota?

I suspect that it may be a design problem, in which case it's really unfixable, other than by replacing the head unit.

However, it occurred to me that it could just be a great deal of variability in the factory head unit, such that there are good ones and bad ones.

If it's the latter, then I guess there's a reasonable chance that getting the head unit exchanged under warranty might fix it. If it's the former, then I suppose my only choice is to change the head unit for one that will work OK.

It'd be nice to know if anyone has had this fixed, before I resign myself to paying loads of money out for a replacement.

Jeremy

 

I believe someone in this thread or another related thread said they went to the dealer about the problem and they replaced the HU. I am also pretty sure they said it did the job. I will try to locate the post.

 

Yes thats correct, I've read that too. And apparently his was fixed.
I just got mine replaced but it didn't make any difference. Still no reception when I turn on the map lights.

Oh I found something else today. If you adjust your side mirrors it will also effect the radio. You might have a hard time to tell the difference with normal radio but with DAB it is too clear.

 

Thanks for that.

I have another data point to add, as I tried another experiment yesterday afternoon. I found a long (just over 2ft) roof antenna from an old Renault and turned the thread on the end down to M5 to fit the Prius roof fitting. This gave it a pretty big antenna, probably 4 times bigger than the standard one.

The disappointing thing is that it made no real difference to the problem, as far as I can tell. The radio reception was just as prone to interference as before, if anything a bit more so. The only thing that did change slightly was that the radio carried on receiving a noisy signal under a nearby short tunnel, whereas before the signal would pretty much fade away completely, leaving just the noise bursts.

It seems that the problem may not be related to signal strength directly, as I'm pretty sure that the big antenna was significantly increasing the signal to the radio, judging by the performance in the tunnel.

I'm going to try and get the dealer to change the radio head unit, in the hope that this will fix it.

Jeremy

 

Yes this was discovered a while ago I think either earlier in this thread of another. Some people added boosters and even bigger antena but it only boosted the noise.

It is to do with the electric lume or the unit. I personally think they havn't even tried to fixed the units on the new ones either because there are no differences at all.

Even if you change it to a new one it will be the same.

 

Jeremy,

This is why I wonder about the amp in the antenna base. And whether it is, in your case, powered or not. If the amp is shot, mistuned, or just not powered, putting a bigger antenna on that screw up there isn't going to push that much more of a signal through said faulty amp.

Took a 60-mile trip yesterday, getting out of range for the NYC stations, but in range for the Philly stations. On the way back I was still getting the Philly stations, line of sight maybe 70 miles, with just a little static, before I switched back to the NYC ones.

I really think that this isn't some basic design error in Priuses, because, certainly, at least my car's data point has a good radio system. Now, a lot of bad head ends, radio amps, connectors, or what all I'll believe, with your car in that group.

Good luck at the dealer!

KBeck.

 

Thanks, I've run through a series of checks, including checking the 12V feed to the antenna amp, and so far everything checks out. I agree with you that if the amp, or radio front end, has a problem then the bigger antenna isn't going to help much.

The problem may be worse on European head units, as we have RDS (not sure if this is available in the US or not). The Alternative Frequency function on RDS allows auto-tracking of national stations as the frequency changes from area to area and I generally leave this on. In my area I can receive the same national station on three different frequencies and have noticed in the past (on other cars) that this can cause the RDS AF system to switch frequencies fairly frequently. I've been wondering if this might be exacerbating the problem.

I think you're right about only some radios being affected. I can't believe that there is a general design fault that's as bad as my radio - if there was people would be returning their cars en masse.

Time for another round with the dealer to see if they can fix it..........

Jeremy

 

Just picked up my new replacement Prius this weekend. It has the stock radio, and the FM reception is *every bit* as bad as it was previously. Meaning from my area in Orange County (south east), you can't listen to FM. I'd hazard a guess that if I went to the beach, it also wouldn't be listenable...

 

What is the build date on this one?

 

Pretty new - March...

As a side note, the silver now comes with a dark gray interior (much better IMHO to the misty gray)...