100% Free

No Scanner Needed

Carly logo
Prices

florianwolf1

Grandeur MOST Bus Fault

Hi, I have a 2011 Hyundai Grandeur diesel with only 32993 km. My audio system is completely dead - no audio output, navigation doesn't work. Diagnostics shows a MOST bus fault. I suspect a bad control unit on the fiber optics network. Any ideas?

Summary of the thread

A 2011 Hyundai Grandeur experienced a complete audio system failure, with diagnostics indicating a MOST bus fault. The suspected cause was a faulty control unit on the fiber optics network. After checking fuses and confirming no aftermarket installations, it was suggested that pinpointing the exact faulty module without advanced diagnostics would be challenging. Ultimately, a shop visit confirmed a faulty amplifier on the MOST bus, which was replaced to resolve the issue.

Did this summary help you solve your problem?

4 comment(s)

AnBeck19

MOST bus issue on a Grandeur, huh? That's a less common one. Are you sure all the fuses are good? And has any work been done on the car lately? Aftermarket stereo install or anything like that? A failing module can bring the whole thing down, so the diagnostics are probably right.

florianwolf1 (community.author)

Fuses are good, checked them twice. No aftermarket stuff installed, everything is factory original. Is there a way to pinpoint which control unit is causing the problem without replacing them all?

AnBeck19

Pinpointing the exact module on a MOST ring without advanced diagnostics tools is really tricky. It could be the head unit, the amplifier, the nav module, or even something seemingly unrelated that's hanging off the bus. Honestly, unless you have access to a proper Hyundai diagnostic system that can talk to each module individually, you're probably looking at a shop visit. Brace yourself, those MOST bus repairs can be pricey.

florianwolf1 (community.author)

Thanks for the info. Took it to a shop, and they confirmed it was a faulty amplifier on the MOST bus. Repair cost me 1000€ to replace. Annoying, but at least it's fixed now.

rmh_community_comment_box_header

community_crosslink_scanner_headline

community_crosslink_scanner_intro

community_crosslink_scanner_title

community_crosslink_scanner_price

community_crosslink_rmh_headline

community_crosslink_rmh_intro

community_crosslink_rmh_title

community_crosslink_rmh_subtitle

community_crosslink_rmh_brand

HYUNDAI

community_crosslink_rmh_model

GRANDEUR