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Mike, Mechanic
Category: Volvo
Satisfied Customers: 39198
Experience:  Tech Expert
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How to possibly correct error fault on HU 850 cd player

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how to possibly correct error fault on HU 850 cd player
Hello and Welcome.
My name is MIKE..
Please tell me exactly what the fault is you have.. what caused it if you know.. and exactly what is displayed on the set ....
Rgds, MIKE...........................
Customer: replied 2 years ago.

Hi Mike sorry for the delay in replying,battery ran down (lights left on)!! bump started the car turned on the radio to see if I had to enter a code and error on cd screen, removed fuse etc still no luck.

I await your reply thanks

Bill S

Hello again Bill - Thats fine no problem..

- Im afraid that 9 times out of ten, this is going to mean taking the set out - opening and stripping it to find and repair the fault.

A lot of people just opt to replace it with another second hand set or different aftermarket system altogether when this happens - but it is worth -as it has to come out anyway, either opening it up yourself if you are handy to do that, or, have someone check it for you.

Often times its a stuck cd- a home burned one - many of these cause that .. or, you find the mechanism is dried out -needing grease on the cogs etc just to get it going again.

This radio shouldn't need a code Bill - it should come back on re connection of the battery so its not that.

One thing you could try Bill is a "reboot".. to do this - disconnect your battery again.. make sure the keys are out of the car.. then connect the two battery leads together.. clamp / connect them with a wire.. and leave like that for 30 mins.. then disconnect them and re connect them to the battery.

This has the effect of draining the residual memory effect in the radio computer - a bit like a reboot on your home pc and will work if its just an electronic glitch -so you can try that.. I would suggest to try it.. and see what happens.

If it works, great - If not.. you will need to do as above Bill.

Let me know how you go..and / or let me know if you need anything further on this.. -

~~~ Meantime ----- Please do click on the Exc / Ok ratings for me at this time.. - Thank you in advance for that -

... Note that you can get back to me anytime at all after doing the rating should you need more at all - it doesn't close you out --

Best Rgds, MIKE.

Mike and other Volvo Specialists are ready to help you
Customer: replied 2 years ago.

Hi Mike sorry for my delay in replying, I removed the unit but had no success so I think a new or recon unit is my best bet, but since replacing the unit and reconnecting the battery terminals there was a long continuouse bleep and the air bag service warning stays on.

many thanks


Hello there Bill -
Thank you for your message.
-- With the issue that you now have Bill... when you disconnected the battery ( car battery ) that can happen but should reset itself. If it wont reset, there is a possibility you have disturbed one of the wire that circuit.
Check the fuses as well Bill for the Air bag circuit - ( if you do have to remove the fuse to check - you should disconnect the battery -and leave it 10 mins at least before refitting the fuse that it doesn't cause it to go off.. )
Airbag system wires are easily tugged / snagged and pull the connectors so check on that.
Another common issue that will cause this is if the seats were moved right back - to help working on the dash area.. it can often tug a connector under the seat/s... so thats another tip to check if that applies.
Other than that - IF you cannot suss will need to have a diagnostic machine plugged into the car to scan the Airbag system - this will produce a fault code and will tell exactly where the fault is.
Could have been pure coincidence Bill - but do check the connectors etc first.. If it comes to having it checked -most small garages have the equipment now so you shouldn't need to use a dealer - that will be cheaper for you..
I hope that all helps you further Bill..
-- Can I just ask, I do just need you to click on the Exc / Ok ratings for me at this point please - and I thank you in advance..
Best Rgds Bill - and you are welcome back anytime -