Chinese replacement HUs?

The amplifier is at the base of the antenna and is powered via a separate lead. There's no diversity set up, just a single antenna for AM/FM, at least on the European JBL model I have. I'm pretty sure that the FM problem is with the stock head unit just being deaf/noisy/having poor selectivity/poor interference rejection.

Jeremy

 

I'd be grateful if you could let me have the sys.txt file, PaJa. My email address is jeremyharris(at)mayfly(dot)eu (please make the obvious anti-spam changes).

I've now received the antenna adapter needed to adapt the European Prius cabling to the DIN socket on the new HU, so will try and get the install done this weekend. It looks to be the right one, as far as I can tell, although I got the part number wrong in the earlier post (I've now edited it). The correct Connects2 part number is CT22AA78, not CT22AA79.

Regards,

Jeremy

 

I've just taken a photo of the adapter and it is very similar to Frenchies, but only has a single coaxial connection, rather than the two shown on his photo. I've attached the two photos for comparison. The one on the left, with the yellow tint, is Frenchies, cropped to be the same size as the one I've taken.

It looks like the headunit may be able to accept two antenna connections (perhaps for diversity reception?) but only uses one connection normally. Looking at your photo it seems as if the only connection used is the top one (in both of the photos) which means that the adapter probably will fit. I shall keep my fingers crossed!

Thanks for agreeing to send the igo file, its much appreciated.

Jeremy

 

Phew!

I've spent the whole afternoon and most of this evening working on getting nav software to work on this head unit, on the bench (I've not installed it in the Prius yet, that's tomorrows job!). Even with the great advice from here and the help from PaJa with an emailed sys.txt file its been a bit of a struggle. It seems that all these units are different and need a particular set of configuration files to make them work.

Anyway, I've learned a fair bit along the way and now have a unit that will run iGO8, TomTom and MemoryMap. Key to getting some things to work was finding ways to access the WinCE 6 OS directly, with no way of using Active Sync to connect to a PC. I used a freeware utility called CE Commander (CECMD.exe) to gain access to WinCE, by spoofing the head unit into loading it from the microSD card instead of a nav program. I then used another freeware program, jotkbd.exe to give me an on-screen touch keyboard and yet another freeware program, Simple Registry Editor, to edit the GPS configuration in the registry and allow MemoryMap to get GPS data. These latter programs can be accessed from the WinCE Windows Explorer that you can get at by using CE Commander.

So, I now have three microSD cards, set up with the three software packages, and I can just use whichever I wish. For just driving around without route guidance I think Memory Map will be neat, as it provides a high resolution moving map, centred on the car. As this runs any UK Ordnance Survey map, including the 1:25,000 scale OS aerial photos, it should make for a useful feature in the dash.

Although I've been using TomTom for years and really thought it was the best nav system going, I have to say that I'm impressed with my initial view of iGo. I can't wait to get it in the car and start playing with it!

BTW, I've discovered that this simpler Chinese unit supports RDS, including AF and TA, and also has CANbus connectivity that accepts some signals from the car, like the "lights on" signal. From all the research I've done so far it looks very much as if it will plug directly in to the car and will provide all the right signals to interface directly with the JBL sound system in the European Prius. It even has the right AMP connection to switch the JBL amplifier on.

Jeremy

 

I agree. I fitted a Kenwood DNX5220 in my last car, because I was disappointed with the Honda built-in nav system. I regret to say that the Kenwood wasn't much better, in many ways it was like the Chinese unit but without any ability to try and fix the stuff that wasn't right. The inflexibility of the mainstream manufacturers is the real problem, they don't seem to want to venture into the limited open architecture market at all.

I can't help but think the same as you, as soon as someone comes up with a rugged, well-featured open architecture platform for in-car use the better. As other products have shown, once you allow software developers a chance to produce good apps your market share increases. I'd guess that whoever does this first (and well) could grab a fair slice of the aftermarket ICE market. There's also an opportunity for value-added retailing, too, by offering customised versions pre-loaded with a set of apps.

BTW, you can run a browser, I think, as there's a copy of IE on the WinCE version that's installed and the control panel has options for network settings etc. Whether or not the USB port would recognise a wireless dongle I don't know.

As soon as it cools down a bit I'm going to go out and have a go at fitting the head unit - its a bit too warm (for the UK!) to be sitting out in the car pulling trim panels off and playing with wires.

Jeremy

 

Well, I finished the install this evening. It was pretty easy, as all the connectors just plugged directly in to the Prius loom. I did two small mods to make the install a bit simpler. I discovered that the Chinese HU didn't have a pin in position 9 on the main power/front speaker connector (the 10 pin one). This is the pin that provides the turn on signal to the JBL amplifier. The Chinese HU did have an AMP-C turn on wire coming out the back though, so I managed to find a spare pin from an old adapter lead, fitted it to the connector and hooked it up to the AMP wire. This worked a treat and allowed the JBL amp to work just as it does with the stock head unit. The photo below shows the mod to the connector.

Next, I decided it would be easier if I wired the aerial amplifier power feed to the ANT + wire on the head unit connector, rather than directly to the car loom. I used the Connects2 Toyota adapter, part number CT22AA78, which fits directly to the EU Prius aerial lead and has a DIN aerial connector that fits to the head unit. You can see the aerial amplifier power feed on the blue wire in the photo below.

Modified power connector.JPG

Interestingly, the EU head unit has two antenna sockets, see the close-up photo below. It only uses one of them, but I can't help but wonder what the second one is for. Maybe the receiver has a diversity capability that isn't used?

Close up of EU JBL HU aerial connector.JPG

Rear view of EU JBL HU.JPG

The only thing that I found I needed to play with during the install was the head unit position. I needed to fit some 7mm thick spacers under the fixing bolts that hold the unit in the dash, just to get the spacing right. The finished install looks pretty neat, and could easily be taken for OEM.

So far I've not had much time to play with the unit, but it's clear that the FM radio is significantly better than the JBL unit. It still suffers from some noise, but virtually all the multipath that made the standard unit unusable has gone. The nav seems to work OK, although so far I've only driven around the local area using iGO. Playing music from USB sort of works OK, but the interface could be better. The same goes for much of the functionality, its not at all intuitive and the manual is rubbish.

Finished install - main menu.JPG

The major downside so far is that the radio goes off when you switch to nav. This is a big problem for me, as even the rubbish Kenwood unit I had would display the nav screen with the radio or USB MP3s playing in the background. I can use the Picture-in-Picture feature to get the nav screen to display on top of the radio screen, but it's pretty unusable like that as none of the nav controls work. As soon as you switch to the nav screen the sound cuts off.

On the upside, RDS seems to work on FM radio. It displays some station information and the Alternative Frequency and Traffic Program functions seem to work. AF has some quirks though, as it just seems to put the radio into "scan up" mode whenever the signal drops below the station change threshold. This is OK if the next frequency for your selected station is higher than the frequency that your on, but a royal pain if its below, as the thing just scans the whole band to loop around and find the right frequency. My two local frequencies for BBC Radio 4 are 92.7 and 92.9, so 50% of the time it goes the long way around when switching...........

I'm not sure whether I'll keep it or not. The improved radio reception is a real plus, as is the very neat look in the dash and the excellent choice of navigation software. Some of the other "features" are not so welcome though, like the poor RDS, the inability to listen to anything whilst the nav screen is active and the quirky interface when navigating music tracks on USB.

Jeremy

 

If I was looking primarily for a nav/MP3 solution then I may have done just this, but my primary motive was to get the FM radio to work well, as the standard JBL system radio is nothing short of appalling. Going to a head unit with nav etc seemed like a good idea, simply because these units are made to fit the non-standard hole in the genuine Prius dash facia adapter.

I'm not wholly convinced that these Chinese units are the best solution, but they certainly match the car very well in terms of look. They don't look like an aftermarket accessory, which is nice.


Jeremy

 

I've swapped the Chinese unit out and fitted my old Kenwood DNX5220, even though I don't like the Kenwood much (its slow to boot up, has poor screen resolution and I really dislike the user interface).

The Chinese unit is on eBay and seems to be attracting bids OK. I'm sure it will be fine for whoever buys it, as its essentially a good unit but one that just doesn't really meet my specific needs.

The FM radio reception on the Kenwood is a bit better than that of the standard radio, similar to that from the Chinese unit. However, the reception is very significantly worse than when the same Kenwood unit was installed in my Honda CR-V. This has been a useful accidental consequence of my experimenting with head units, as I have been able to fit the exact same head unit that worked very well in one car into the Prius and hear the massive reduction in FM radio performance.

My conclusion is that the FM radio problems may well stem from the car or the aerial system, rather than the head unit.

I'm not happy with the Kenwood, as I never liked it when I had it in the CR-V, plus it doesn't look good, even though I've used the Metra infill pieces. I can confirm that using a standard Toyota to Kenwood wiring adapter worked OK, to use the JBL amplifier all I needed to do was move one pin on the connector from pin 8 to pin 9. This enabled the JBL amplifier which works well with the Kenwood - no expensive amplifier interface was needed.

Jeremy

 

That's useful, thanks. I like the look of the Alpine IXA-407BT, which seems to have a really nice user interface. The screen resolution is still pretty poor though, no better than the Kenwood DNX 5220, plus I'd need to buy the add-on nav module. I took a look at the Pioneer range, but they are pricey here in Europe and the nav system doesn't look too good to my eye.

I'm off driving around France next week, so will, no doubt, get fed up enough with the Kenwood to go and get something else..........

Jeremy