OBD Errors & Head Unit Help!

[Donk]

The battery on the van had gone flat. I ended up jump starting the van yesterday. Done it numerous times before, correctly and no reversed polarities etc. However the van clearly didn’t like it.

The head unit - Alpine Halo 9 will not turn on now.

It gets power fine - yellow and black checked with voltmeter at the rear of the head unit.

The ACC lead (accessories trigger to turn on the head unit on key being turned) does not seem right. When I check it I’d have expected that to go live - effectively +12v but when I tested it shows -12v.

Ran an OBD check and there are 3 faults showing:

(1) Central electronics: 03435
(2) CAN network gateway: 03158
(3) Instrument cluster: 13654544

(1) Relates to Terminal 30 for Inside-Light / Parking Light
(2) Relates to Control Module For Information Electronics 1 (J794)
(3) Relates to Instrument Cluster ...

Is it just the interface Alpine APF-X300VW UART Interface that’s damaged and not sending the ACC signal correctly or is it another van module?

Any pointers as to what I need to do / check or is it a book into VW dealers to sort?

Thanks.

 

[Dellmassive]

do a full van reset first . .

[Guide] Full Van ECU Reset (Capacitive Discharge) -- How I Done It --

Full Van ECU Reset (Capacitive Discharge) -- How I Done It -- The T6 is full of ECU`s, Modules, CAN Buses and Data packets . . . . . Just like your Phone or PC right. The motor vehicle industry has spent years with research and development making the modern car/van Data and electrical system...

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then if no change, check ALL the fuses with a meter . . ignition ON, using a meter to test for power on each tab exposed on the fuse . . . that way you have to remove then,

or loose them,

or put them back in the wrong slot.

 

[Donk]

Thank you. I'll give that a go and see what it does.

 

[Donk]

Woooohoooo!

Capacitive Discharge worked @Dellmassive . I am so happy again and the van is back in my ‘good books’. I’ve even treated it to a trickle charger. I can now continue with the sub and amp install now.

Thanks!

 

[Dellmassive]

@Donk

Glad that it fixed. Well done.

#flatbatterygremlins



What charger did you go for?

 

[Donk]

Went for a CTEK MXS7.0 In the end.

 

[Dellmassive]

Nice..

 

[Donk]

Aaarrgggghhh! All is not right.

With the ignition on the headunit works fine. When I select reverse the reverse screen pops up and the reversing camera displays its image perfectly like it used to. Go back to park and previous screen displays fine. So all is good.

I’ve now turned the engine on and the headunit immediately displays a reversing screen irrespective if I’m in park, drive or reverse. No camera image is displayed either - just a blank screen with the guidance lines. I can not navigate out of this screen - headunit is stuck in it! I turn the engine off and all behaves as it should.

I don’t understand.

Help....

 

[Robert]

Try different power supply point, even cigarette socket.

 

[Donk]

Try different power supply point, even cigarette socket.

I‘ll give it a go. Just don’t get why it goes wrong when the engine runs. Never used to. Even with the camera + feed disconnected the unit still immediately goes to the blank reverse screen.

 

[Dellmassive]

Could be an issue with the CANbus module that generates the RVS signal.... ?

 

[Donk]

Try different power supply point, even cigarette socket.

The supply was taken straight from a good ground point and back to a spare fuse point in the centre column along with the other fuses. So supply is good. I tapped into the green/brown wire for the reverse trigger so was fine.

Could be an issue with the CANbus module that generates the RVS signal.... ?

Is this the interface module - in this case an Alpine APF-X300VW? I'm guessing like the Connects2 modules.

 

[Donk]

Well I’ve no joy with getting it all working again.

I’ve checked the fuses.
I’ve done another discharge to reset it all.
Run another OBD scan with the following:

Instrument cluster: 13654544
Parking/steering assist: 1079572
Central electronics: 03435
CAN network gateway: 03158

The head unit reversing camera comes up and functions fine with the ignition on and works as it should. But turn on the engine - still in Park and not even selecting reverse - and straight away the unit goes to a ‘reversing screen’ but with just the guidelines and no image, like this:

Also the interior cab lights do not work - which I think is controlled by the BCM?
Any ideas on what to try or do next before going to VW or VW specialist or good auto electrician?

 

[mmi]

03435 - Terminal 30 for Interior Light/Parking Light
------
03158 - Information electronics control module
- most likely No signal/Communication thus Head unit is offline.
- most likely as a consequence of the above the other two faults as Head unit is not communicating with Instrument cluster nor Parking/steering assist as they expect.

If you clear the faults - do they reappear immediately or only when engine is started? If the latter would be interested to hear if the power is supplied from cigarette lighter socket.

 

[Donk]

@mmi, I’m at work till the evening so will try that when I get home to see what happens with the fault codes.

The camera was wired so that all the cables were taken back to the dash area. The power feed was taken straight from an empty fuse socket. The reverse trigger was taken from tapping into the green/black cable.

 

[Robert]

@mmi, I’m at work till the evening so will try that when I get home to see what happens with the fault codes.

The camera was wired so that all the cables were taken back to the dash area. The power feed was taken straight from an empty fuse socket. The reverse trigger was taken from tapping into the green/black cable.

Did you try to connect reverse trigger to any other source?
Even temporarily for verification purposes?
I suspect that you are using reversing lights as your trigger and when engine is running your BCM sends PWM instead of DC and this "confuses" your head unit.

 

[Robert]

...
I tapped into the green/brown wire for the reverse trigger so was fine.
...

...
The reverse trigger was taken from tapping into the green/black cable.

I am a little bit confused.
Where did you take your reversing trigger from?

 

[Donk]

I am a little bit confused.
Where did you take your reversing trigger from?

The light green with black in it. Picked it up in the loom near the base of the A pillar on the passenger side.

 

[Donk]

Did you try to connect reverse trigger to any other source?
Even temporarily for verification purposes?
I suspect that you are using reversing lights as your trigger and when engine is running your BCM sends PWM instead of DC and this "confuses" your head unit.

Erm. Right I understand what you’re saying. What I will try then is a direct positive feed to the trigger initially perhaps?

 

[Robert]

Erm. Right I understand what you’re saying. What I will try then is a direct positive feed to the trigger initially perhaps?

Perfect idea !