Reverse signal for dashcam rear view

[Robert]

Or keep it handy and change your complete BCM coding from :
E0A4303A0A212031002009742E2B9C500F00708F60464DE0320400220800
to
E0A4303A0A212031002009642E2B9C500F00708F60464DE0320400220800

 

[Cb83]

Changed it now so will see how it goes in the morning when I reverse into my space at work, many thanks again @Robert

 

[Cb83]

Success thank you again @Robert

 

[Robert]

You are welcome .

 

[Frazthoms]

Sorry to add to an old thread but I’m connecting a rear dashcam to my 2019 T6 and trying to find the near side rear cable with the reverse light trigger. When engine is on and in park, all cables bar one (pin 4) are showing live. When I put into reverse the cable that was not showing live (pin4) remains not showing a live… in other words no difference when reverse in engaged.
there is a reverse camera already fitted by factory and I’m wondering if there some coding been done to alter the normal reverse light trigger on this cable that remains dead (pin 4).

the problem I have is I am handing off the van at the weekend to get boarded out so don’t have long to tap into this elusive cable.

can anyone help please.

here is a pic of the near side rear light block and cables I have (I don’t see a black/green cable)

thanks
Frazer

 

[Frazthoms]

I’ve since found the reverse trigger feed on the factory fit parking cam but it’s intermittently triggering the rear cam, probably too weak. I’m going to fit a relay with a proper 12v live and see.

 

[Cb83]

You may well find as I did that the signal is pulse width modulated, and some coding can rectify this, I'm sure a relay will do the same thing if you don't have access to vcds.

 

[david173]

I used a new 12v feed from the fusebox under the dash and used the reverse feed to trigger the relay to send this feed to power the camera.
I found because of the BCM in the car doing things to the signal (beyond my understanding) my relay played up, in the end i used a relay with a diode as recommended by another forum member which solved the problem. Might be worth getting that relay just incase. This one from memory :Halfords HEF560 Relay 12V 40A 4 PIN inc. diode | Halfords UK

 

[Frazthoms]

Thanks all.

I’ve ordered a relay with a resistor and hopefully it works but if not then at least I can pull off the tailgate panel to get to it and play. I’ve ran a ground and live feed into the tailgate so should eventually get there.

what was weird was I couldn’t find the references black/green cable and all the cables on the rear light block were live on ignition except one which was dead even with reverse engaged…

thanks again.

 

[Howzat]

You might want a relay that switches straight on but delays when the 12v reverse is cut for the following 2 reasons.
1. The pulse issue won't be an issue anymore so no coding required.
2. The reverse camera will stay active for XX seconds (is it 5?) like the rear sensors do.

Something like this 12V DC Delay adjustable timer relay which lets you set the delay from 0.1s to 25s.

 

[paddy26]

First thing I would do would be to check and make sure that Byte 11 Bit 4 is deactivated(unticked) in 09 BCM.

Thanks for this. It fixed the issue I had with my retrofit camera.