Source on radio changes by itself

[Bhavishize]

Hi there,

I am having an issue with my 2014 Honda Vezel where the source on the radio would change by itself, that is, it would jump from FM to AM on its own.

Could someone advice me on what I should look for and how I can diagnose the issue.

 

[static zap]

Check for jammed , dirty buttons . Are you pressing preset station buttons when this happens?
If happens with presets - one has been saved set to AM.
( If you are in a poor reception area .. may just be one of "Those"
lost station ,Seek something different- features -- )
...My antenna loves lying flat to vehicle on windy days on motorway!
(Sorry no actual experience of your model !)

 

[Bhavishize]

Thanks for your advice.

However, it is a touch screen head unit and the issue happens even when it is in Bluetooth mode where it would jump to DVD.

I am not sure if the issue is coming from the head unit itself or from the Steering Wheel Control.

 

[static zap]

However, it is a touch screen head unit and the issue happens even when it is in Bluetooth mode where it would jump to DVD.

I am not sure if the issue is coming from the head unit itself or from the Steering Wheel Control.

Sounds like you have a suspect , but poor communications may also give strange results. Loose connections- etc
...Steering-unit (Any floppy bits well worn responding to bumps / cornering g forces --- Not that likely ..but watch for )

 

[Bhavishize]

The connections on the head unit as well as on the SWC has been checked. This issue happens even when the vehicle is stationary.

When the vehicle has just been turned on it would jump source multiple times within 10-15 seconds interval. After a few minutes of leaving the car running, the interval becomes longer maybe around 2-3 minutes.

 

[Bhavishize]

Hi there, I have connected a voltmeter to the SWC wire going into the head unit and recorded the video.

Change in mode happens at:

1) Start of video
2) 1.56
3) 3.39

I changed the source manually on the wheel at 2.15.

Please see if anything can be determined from the video.

 

[static zap]

Unsure if this advice is of any use.
Could steering wheel unit be left disconnected ,to so see if any bad signals are on the comms lines , or will that render the screen un-usable ?
(thinking if random seek event still happens -ruled out steering wheel unit ,)
Is that 24V supply we are looking at on meter ?
(Will re-watch when not so busy)
...Poor earths are good at letting noise signals in !

 

[Bhavishize]

Unsure if this advice is of any use.
Could steering wheel unit be left disconnected ,to so see if any bad signals are on the comms lines , or will that render the screen un-usable ?
(thinking if random seek event still happens -ruled out steering wheel unit ,)
Is that 24V supply we are looking at on meter ?
(Will re-watch when not so busy)
...Poor earths are good at letting noise signals in !

The wire sending SWC signal to the headunit has been cut just before the adaptor and the head unit works without any flaw. But of course, I cannot use the controls on my steering wheel.

The value on the meter is in mV.

Any idea how I should check if the earth is good or not?

 

[static zap]

Is there anything else connected to the SWC line other than head unit and Steering wheel controller.
(If present could be making the conversation difficult).
.. If getting parts to swap for fault finding is expensive -Must consider part talking or listening could be to blame !
[automerge]1574539266[/automerge]
Is steering wheel part stationary .. or part of steering wheel that moves (so may incorporate a clock spring ?)
[automerge]1574540523[/automerge]
When my clock spring failed -Lost Horn (but not Airbag !)
..Not a Honda .. Sadly looks like you have plenty of buttons !
Had a glance at Steering wheel in manual pre view.

 

[Bhavishize]

Hi,

I realised that this issue started happening after I plugged in a USB adapter in the 12V power socket to charge my phone.

After I removed the USB adapter, the radio now works without issue and I can use the controls on the steering wheel as well.

I did not consider that the USD adapter might be the issue but it might have been causing some interference to the SWC signal.

That's very strange but the radio now works normally after removing the USB adapter.

Will supervise the radio for next few days in case the issue resurfaces

Thanks a lot for your help and support

 

[littlespark]

You may have found the answer already.
Some USB adaptors can cause enough interference to affect radio and Bluetooth

 

[static zap]

Side note for unanswered -Earth test ..
(Saving discussion about testing earths for another day)
Schematic of equipment -occasionally gives clues-In dark without !
(some advanced equipment may have 2 ground systems ...
digital grounds , or balanced signal lines !)