Horn Got Disconnected, Now What?

Oka · Post by **Oka** » 04 Jan 2022, 21:03

Took my XC90 to get remote starter installed. When the car was pulled inside the shop for them to start work, the horn started, was continuous until they unplugged the horn connections. This took them long since that was not expected. They connected it, and it started again. So now, there is no horn.

What should I do now? I can't remember the last time I used my horn; but I need it. What should I do?

Cheers

Post by **ggleavitt** » 05 Jan 2022, 10:19

http://vidaresources.volvocars.biz/ewd/ ... 998202.pdf , it's for MY07 but you'll be fine.

Horn power comes from the CEM triggered by the steering wheel module (LIN bus). Zero idea what your install has done to make the horn stay on but the EWD may help point out the cause.

Good luck

Post by **xHeart** » 06 Jan 2022, 07:51

Keep one in the car while you fix it:

Post by **Roger_850T** » 10 Jan 2022, 19:49

Do you have Vida and a Dice unit? The horn switch is connected to the Central Electronics Module, CEM, and the CEM controls the horn relay. It would be useful to know if the CEM thinks the horn is activated or not. That will help troubleshoot whether it's the input side, or the relay, or something else. It's conceivable that they got something mis-connected when they did the remote starter. Or, the security system may be trying to activate the horn. Good luck!

Roger

Oka · Post by **Oka** » 11 Jan 2022, 23:59

ggleavitt wrote: ↑05 Jan 2022, 10:19 http://vidaresources.volvocars.biz/ewd/ ... 998202.pdf , it's for MY07 but you'll be fine.

Horn power comes from the CEM triggered by the steering wheel module (LIN bus). Zero idea what your install has done to make the horn stay on but the EWD may help point out the cause.

Good luck

Could not download the PDF due to potential securities. Is this file safe to download so I can disable my security systems to download it.?

Please, what is "EWD"?
Thanks.

Oka · Post by **Oka** » 12 Jan 2022, 00:02

ggleavitt wrote: ↑05 Jan 2022, 10:19 http://vidaresources.volvocars.biz/ewd/ ... 998202.pdf , it's for MY07 but you'll be fine.

Horn power comes from the CEM triggered by the steering wheel module (LIN bus). Zero idea what your install has done to make the horn stay on but the EWD may help point out the cause.

Good luck

Am able to download the PDF, however, I am not an electrical diagram reader, am ignorant in that knowledge.

I had asked what "EWD" is, now I assume it is "Electrical Wiring Diagram".

Oka · Post by **Oka** » 12 Jan 2022, 00:08

xHeart wrote: ↑06 Jan 2022, 07:51 Keep one in the car while you fix it:

That's a good one; I will.

: LOL.jpg (28.56 KiB) Viewed 719 times

Thanks

Oka · Post by **Oka** » 12 Jan 2022, 00:12

Roger_850T wrote: ↑10 Jan 2022, 19:49 Do you have Vida and a Dice unit? The horn switch is connected to the Central Electronics Module, CEM, and the CEM controls the horn relay. It would be useful to know if the CEM thinks the horn is activated or not. That will help troubleshoot whether it's the input side, or the relay, or something else. It's conceivable that they got something mis-connected when they did the remote starter. Or, the security system may be trying to activate the horn. Good luck!

Roger

Yep I have the tool. What exactly should I be looking for?
Yeah, you already told me what to check, but could you be more specific, please?
Thanks

Post by **xHeart** » 12 Jan 2022, 06:41

Oka wrote: ↑12 Jan 2022, 00:12 Yeah, you already told me what to check, but could you be more specific, please?

The Volvo EWD reference is a must have for us DIYers. Here is a use of "#page=46" in the URL to access and bookmark specific page; here is CEM page. Try this http://vidaresources.volvocars.biz/ewd/ ... df#page=46