Technical Connecting head unit affects instrument cluster

[Fr1998]

Hi all. I hope someone can help - I'm really stumped.
I bought for my daughter a 64-reg (so pre facelift) 500S with the digital TFT display. It's a lovely car and after buying it second hand I had to leave it on the drive for 3 weeks. As it was cold and wet, I thought I should charge the battery just in case, not realising it could cause trouble.
When bought, the car had a cheap aftermarket Android head unit which worked fine but wasn't very powerful I put in an Xtrons replacement which worked fine. Then I charged the battery a few weeks later.
From that moment on, neither head unit works, and when I connect the ISO harness to the back of the unit, I have the following symptoms:

• Indicator sound stops even though the indicator lights work
• Instrument cluster warning lights come on
• Speed doesn't display in the digital output (fuel gauge doesn't show anything either).
• MultiEcuScan can't connect for a proxy alignment

The car does drive without an issue though, even with the above problems. I can connect with MultiEcuScan once the head unit is disconnected, clear the problems that have popped up, and proxi alignment isn't required.
I was thinking that a surge must have happened during the battery charge but I can't find where the problem actually is.

Everywhere I looked for an answer about the head unit, I saw talk about the B&M unit and that it could have problems. I wanted to check if the unit's firmware was corrupted but found that the download site was no longer available. So, as it could also see, it wasn't really needed (the new head unit would deal with the modern modcons), I wanted to disconnect the unit. Done. And yet, no change.

Does anyone have an idea where I should check?

 

[the green vanper]

Hello,

I think it would be interesting to know with what and how you charged the battery. And what where the errors you cleared once you connected MES.

Factory radio unit and Blue&Me module require proxy alignment, as you already know. With the radio disconnected and B&M module removed I think the system should require the procedure to be done. I don't know how it is signaled on the digital display, on the 'classic' ones the mileage is blinking.

With the new radio connected, can you see all the modules while scanning with MultiEcuScan? BCM? Display?

Have you checked the earths? I see that you have no problems with starting and driving, but it's a common problem in the 500's. I wanted to upload the eLearn docs for the 2014 model, but can't get access to them now

 

[the green vanper]

OK, I managed to get all the earth docs.

They will be available probably in the morning here:

https://www.fiatforum.com/downloads/x150-500-elearn-e1020-earth-docs.616/

 

[John202020]

To start with,
Does EVERYTHING work as expected on the rear hatch, lights ,handle release wiper etc?
Next disconnect everything to the factory harness with the radio including the ones you attached unless youre sure theres no bridges , see what happens?
When charging the battery did you disconnect it unlikely to be a surge if it was connected?
I worry the display is fried,

 

[A3jeroen]

What happens if you disconnect the CAN line to the radio?

gr J

 

[Fr1998]

Wow. I really appreciate the responses. I wasn't expecting so much in one day.

Hello,

I think it would be interesting to know with what and how you charged the battery. And what where the errors you cleared once you connected MES.

Factory radio unit and Blue&Me module require proxy alignment, as you already know. With the radio disconnected and B&M module removed I think the system should require the procedure to be done. I don't know how it is signaled on the digital display, on the 'classic' ones the mileage is blinking.

With the new radio connected, can you see all the modules while scanning with MultiEcuScan? BCM? Display?

Have you checked the earths? I see that you have no problems with starting and driving, but it's a common problem in the 500's. I wanted to upload the eLearn docs for the 2014 model, but can't get access to them now

Thanks for putting the files up, I've downloaded them and will go through them in a bit.
I charged the battery using a mains-powered automatic 12v car battery charger. I've attached a PDF of the errors found before clearing (they cleared without an issue once the radio was disconnected). The mileage was blinking and proxi alignment worked.
Unfortunately, with the radio connected (ISO harness) I can see the modules, with errors, but proxi alignment comes back that it can't connect.

I would add that the car came without the OEM radio, just an android unit (which was working).

As for the earths, that's where I was heading next. I was wondering where the other end of the ISO harness plugs into in case there was a grounding problem there. I'll look at the docs you sent.

 

[Fr1998]

To start with,
Does EVERYTHING work as expected on the rear hatch, lights ,handle release wiper etc?
Next disconnect everything to the factory harness with the radio including the ones you attached unless youre sure theres no bridges , see what happens?
When charging the battery did you disconnect it unlikely to be a surge if it was connected?
I worry the display is fried,

Rear hatch works fine. I've heard that there can be problems with the harness to the hatch and am keeping an eye out but so far so good.
Honestly, I can't recall whether I'd disconnected the radio when I charged the battery - it's possible I forgot to do it .

On your line about disconnecting everything, I assume you mean disconnect the radio completely from the ISO harness and Can connector, but I'm not sure what you mean about the bridges. If you could explain, that would help.
In any case, with the radio disconnected everything works fine. Currently the car is running with the Can connector plugged into the radio but the ISO harness (so with power) not connected and all's well - I'm leaving one plug connected so that the cable doesn't fall down the back of the dashboard.

I guess changing the display (instrument cluster?) is going to be a pain and expensive.

 

[Fr1998]

What happens if you disconnect the CAN line to the radio?

gr J

The CAN line makes no difference, as long as the ISO (power) isn't plugged in. With the ISO plugged in, with or without the CAN connected I have the same situation.

 

[the green vanper]

As far as I know, proxy alignment won't succeed when there are errors found on the modules. And looking at the error list I find it normal not to be able to do it.

Do you still have the old radio? If so, can you please reconnect it to check if the errors reappear?

If not, having in mind the fact that the alignment fails only with the new radio unit installed, I'd check what are the differences in how the old / new radio should be connected. I know ISO should be standard...

 

[Fr1998]

As far as I know, proxy alignment won't succeed when there are errors found on the modules. And looking at the error list I find it normal not to be able to do it.

Do you still have the old radio? If so, can you please reconnect it to check if the errors reappear?

If not, having in mind the fact that the alignment fails only with the new radio unit installed, I'd check what are the differences in how the old / new radio should be connected. I know ISO should be standard...

I did the proxi alignment once the radio was disconnected and the codes were cleared. Currently, connecting will create the errors but once they're cleared, proxi alignment just says that there's nothing to align.
I'll have to wait to recheck the old radio on the weekend as the car won't be back before then.
I have the old radio and have tried reconnecting it with the same problem as the new one. Interesting point on the difference in connections but, if both radios worked before I charged the battery, do you think that would be an issue?

I'm going through the earth docs right now - quite a bit there. Thanks again.

 

[the green vanper]

For the earth docs, I've uploaded the whole package for all versions, so pick only the ones that are appropriate for your car. I've uploaded also whole set of the power supply docs for the 500 in the different versions.

 

[John202020]

So the dash display is cooked even with the radio disconnected ?
Sometimes, the iso plug to radio has some wires bridged that can be swapped around depending on installation, but not always.
If you do end up replacing the dash display, which may not be as expensive as you expect, I recommend not using your current head unit. Stick to Pioneer, Alpine, Kenwood etc.

 

[the green vanper]

Stick to Pioneer, Alpine, Kenwood etc.

They are not the same they used to be 30 or 40 years ago. No need to.

As far as I know Xtrons is also a reputable brand. Simply with chinese roots.

proxi alignment just says that there's nothing to align.

I'd say if it can't be seen on CAN, it won't require the alignment.

Rereading the previous posts I'm starting to think that there might be something wrong with the radio installation, perhaps the previous owner messed up something while he connected the previous radio?

Perhaps there's a short somewhere where the radio is connected?

I'm adding other docs, on the different variants of the radio installation + instrument cluster.

https://www.fiatforum.com/downloads/x150-500-elearn-e3510-radio-docs.621/

https://www.fiatforum.com/downloads/x150-500-elearn-e3510-radio-hi-fi-e4090-navigator-docs.619/

https://www.fiatforum.com/downloads/x150-500-elearn-e4010-instrument-panel-e4080-trip-computer.620/