No brake lights !

[JimInNashville]

After describing my problem last week, I called Wilson County Hyundai. A great group of people. They got me in first thing Monday morning. Their top tech, Rich Papineau, told me that they had replaced quite a few of these diodes, and he kept them routinely in stock.

I now test my brake lights each and every morning.

Next time you are in your dealer's, tell them about this problem, and see if they've ever heard of it. Make SURE they have the diodes in stock, because it costs them virtually nothing, they should have them, and if they don't, it might cost YOU a bunch of time.

 

[Eurog]

At 57,000 miles experienced brake light failure on my 2009. Repaired under warranty, the service document is quoted below:

"Owner states none of the brake lights will come on. Tail lights work but not brake lights. Inspected wiring for damage. Found nothing abnormal. Checked voltage through diode. Voltage did not flow in either direction. Removed diode to further inspect and checked continuity. Found no continuity in Z01 under drivers kick / crash panel. Replaced diode and rechecked. All OK after repair"

Part replaced: Number 91789-33000, Diode(2P)

Technical Service Bulletin 09-BE-023, Stop lamp Z01 Diode Inspection Procedure, appears to describe the location and procedure for troubleshooting of the diode but describes the issue as " . . . vehicles may experience the stop lamps blinking on and off even when brakes are not applied."

I hope the new diode is more robust and I do not experience no brake lights again; drivers in Southern California seem to rely on the brake lights ahead of them to determine if they should look up from their texting!

 

[QuantumRift]

I understand what you were trying to say but diodes don't 'short'. Diodes are one way current flow devices that "open" when they fail.
Specifically, in electronics, a diode is a two-terminal electronic component with asymmetric transfer characteristic, with low (ideally zero) resistance to current flow in one direction, and high (ideally infinite) resistance in the other. It acts as a gate to prevent current flow in one direction. Since it is designed with a "z", it is a "Zener diode", without doubt. And a Zener diode's function is to hold voltage at a specific level, as the "Zener breakdown" (or current flow) occurs at a precisely defined voltage. A failure in a Zener is usually NO current flow or voltage at levels other than defined by the zener. Just food for thought (In a previous life, after I was an aeronautical engineer, I was an electronic warfare tech in the Army). Since it's a zener diode, and I assume the brake lights on that model Genny are LEDs, it's purpose is to HOLD the voltage for the LEDs at 5V, prob no more than 5.5 or so. One that is a failing state, that is, experiencing a fluctuating zener breakdown might cause LEDs to blink or flash intermittently, or just cause the LEDs to not light up at all.

Bad manufacturing processes can create batches of faulty or out of tolerance diodes that can fail by either opening (preventing current flow), or not having the proper zener breakdown to provide the proper voltage to kick the LEDs. You'd want it to fail and NOT allow more than 5V DC to the LEDs or they could get obliterated by the high voltage fluctuations. And in our case it's probably a plug in module on the brake light circuit instead of being hard wired or soldered in. Just a guess, though. As it could be a catastrophic point of failure, it would have to easily fixed should it fail.

Take your car into dealership for warranty work. Tell them to check out z01 diode. It probably shorted. Same happened to mine but they fixed it in 40 minutes

 

[QuantumRift]

This deals with alternators but has a good discussion on Zeners.

[ame="http://www.youtube.com/watch?v=RZsRth3T8iM"]How to Do Alternator Relay Failure Circuit - YouTube[/ame]

 

[vitacura]

Happened to my 2010 Genesis recently. Someone let me know at a light that I had no working brake lights. Had it towed to the dealer the next morning and they had it for a day and replaced the diode.

 

[vappro]

Re: No brake lights ! fuze ok

I Just Bougth A 2009 Genesis 3,8 and a had the same issue.no brake Ligths
I took to a dealer and replace the Diode for free . I think is another issue for
recall

 

[vappro]

At 57,000 miles experienced brake light failure on my 2009. Repaired under warranty, the service document is quoted below:

"Owner states none of the brake lights will come on. Tail lights work but not brake lights. Inspected wiring for damage. Found nothing abnormal. Checked voltage through diode. Voltage did not flow in either direction. Removed diode to further inspect and checked continuity. Found no continuity in Z01 under drivers kick / crash panel. Replaced diode and rechecked. All OK after repair"

Part replaced: Number 91789-33000, Diode(2P)

Technical Service Bulletin 09-BE-023, Stop lamp Z01 Diode Inspection Procedure, appears to describe the location and procedure for troubleshooting of the diode but describes the issue as " . . . vehicles may experience the stop lamps blinking on and off even when brakes are not applied."

I hope the new diode is more robust and I do not experience no brake lights again; drivers in Southern California seem to rely on the brake lights ahead of them to determine if they should look up from their texting!

Thank you for the very strong lead . I got it thanks to you

 

[genes2010]

I would encourage anyone that has this issue (or any other safety issue) to report it immediately to:
https://www-odi.nhtsa.dot.gov/ivoq/

I believe this should be a factory recall, just like the brake switch was. Not only is this dangerous for the Genesis drivers, but also anyone driving behind them.

I had my Genesis towed to the dealer when a driver behind me told me my brake lights didn't work. The roadside assistance which came with my car paid for the tow to the Hyundai dealer and the dealer paid for a rental car (after I did some complaining).

 

[Rob]

This just happened to us for the second time in a year. In both cases we were fortunate to have friends who happened to be driving behind us who alerted us to the fact we had no brake lights. At first, if we turned on our lights we got limited brake light use, but that quickly failed too.

I will be filling out a report at the nhtsa site above. I would like to see either a solution to this or at the very least a retro fitted warning system to alert us on the instrument panel that there is a problem.

In the meantime, I ordered an extra diode to keep in the glovebox. At $7, the dealer charged more than list but it was probably less than ordering the part online with shipping and it is worth it to me to have one on hand so that I can fix it myself instead of being towed or risking an accident. It appears to be no harder than replacing a fuse--if you can manage to get yourself under the driver's side lower dash panel to put it in.

 

[pgenesis]

Is there any way that you can post a picture of what this looks like? I saw the picture located in the PDF in an earlier post but not sure what to do with it? Do I cut the tape from around that thick cable and the diode is somewhere inside there?

I took my care into the dealer and they replaced the recalled switch but the brake light still doesnt work. Perhaps this is the culprit. My warranty just ended in January so I am a little hosed from that. Any help would be appreciated!! I have a 2011 genesis 4 door.

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[Mark_888]

Is there any way that you can post a picture of what this looks like? I saw the picture located in the PDF in an earlier post but not sure what to do with it? Do I cut the tape from around that thick cable and the diode is somewhere inside there?

I took my care into the dealer and they replaced the recalled switch but the brake light still doesnt work. Perhaps this is the culprit. My warranty just ended in January so I am a little hosed from that. Any help would be appreciated!! I have a 2011 genesis 4 door.

There were two different recalls that should be fixed without charge regardless of warranty end date:

1. Brake light switch on the brake pedal. It was too sensitive and sometimes caused brake lights to illuminate without brakes actually engaged.
2. Diode in the brake light assembly that could cause the brake light to not illuminate.

 

[pgenesis]

So should I assume that they would have done both of these recalls when I took it to get fixed in January? The light itself is LED so it seems unlikely that it would have burned out. Not sure what else could be wrong with it.

This is the only thing I can find for recalls: http://www-odi.nhtsa.dot.gov/acms/cs/jaxrs/download/doc/UCM467886/RCLRPT-14V713-3073.PDF

 

[Mark_888]

So should I assume that they would have done both of these recalls when I took it to get fixed in January? The light itself is LED so it seems unlikely that it would have burned out. Not sure what else could be wrong with it.

This is the only thing I can find for recalls: http://www-odi.nhtsa.dot.gov/acms/cs/jaxrs/download/doc/UCM467886/RCLRPT-14V713-3073.PDF

That recall was for the diode. You can go to any Hyundai dealer and find out what recall service has been preformed on your vehicle based on the VIN.

The other recall I mentioned about the brake pedal switch applies to Genesis assembled from Apr. 30, 2008 to Nov. 22, 2010. The Hyundai TSB is 13-01-021-3.

 

[Geni09]

Ditto for me too! bad single diode - fixed in the truck area, under the carpet/mat.

Where is the diode located in the trunk? Do you have a picture or diagram?

 

[Gunkk]

http://lmgtfy.com/?q=2009+genesis+brake+light+ diode+located+in+the+trunk

 

[homeofstone]

Where is the diode located in the trunk? Do you have a picture or diagram?

If the recall has not been done on your car, any Hyundai Dealer will install a new one free under the recall regardless of age or miles.

 

[Fredder]

There is a recall on the brake light switch.
Call your dealer, a no charge fix

 

[Geni09]

There is a recall on the brake light switch.
Call your dealer, a no charge fix

It was the brake switch all along!! Recall was done in 2015. What I don't know is once they repair under the recall and it goes out again, do they continue to fix it for free under recall?

 

[Fredder]

There is a recall on the brake switch, no charge fix, take it to your dealer

 

[g_128552]

I am floored thinking I have been riding around with no brake lights anything could have taken place. I am relieved that i can get it fixed at dealer at no cost well at least that is what I have read here.