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Recommended Posts

Hi all,

I had a message come up saying "check license plate lights", are sure enough the bulbs had blown.

purchased the new bulbs and replaced but still have no lights and the message remains.

I cant find a fuse that powers the number plate lights...

Any thoughts on a fuse?, or things to check?

thanks for any help

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Hi loren,

Any pointers where the ground is located?

I took off the number plate lights and their are two wires on the plug that go onto the number plate light unit.

All looks ok, no dirt, no rust, no damage..

Do i just test the ground wire from the plug, or is there a central ground for the rear control ?

Thanks for any help

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I must be looking in the wrong place. I cannot see any ground on the rear light unit.

Today, i looked at the number plate units again.

Checking with the tester i can confirm the light units are both ok as i get a connection sound using the multi-meter

however, when connecting the tester to the two wire on the car i get no reading when the car lights are switched on?

its either bad earth or no voltage getting through..

any more pointers (sorry to be think!!)




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  • Admin

If all grounds and all connectors look and test good (low resistance) then you will likely need a PIWIS tester to check and re-program the rear control module.

Sometimes these control modules get a transient spike that upsets the system and requires a re-program - does not happen often but I've seen it a few times.

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  • 7 years later...

Hi all

I had the same problem with rear number lights not working, I searched nearly every site I could find in the hope of finding a way to fix as in the UK we must have a number plate light working. After checking all fuses and bulbs I brought a high spec obd scanner and writer expecting to find one of the control units had failed but this wasn't the case. The mot was nearly up so I discided to run a cable from my real lights just to pass the mot. I know I would still have the error but happy to put up with for now. So I got to work and found the problem. I found a broken cable where the cables come from the boot to the car. 

I've attached a link of photos 



Edited by markwest
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