[hyundai_i30_2011_owner]

Hi, I've recently replaced the rubber steering coupler in my 2011 Hyundai i30 (this is a common problem). Simply put; disconnect a range of electrical plugs on the steering column, undo bolts/nuts so that steering column comes down, open power steering motor and replace coupler, then put everything back.

After doing all this, my brake lights are on permanently when the ignition is on. When the car is off (engine off and ignition off), the brake lights are off (so that's good). When I then press the brake pedal, the brake lights come on as they are supposed to (this to me suggest the brake switch at the pedal is OK - but I could be wrong). But then, as I said, once ignition/engine is on, brake lights are on all the time, whether brake pedal is pressed or not. I checked fuse and relay (if I got the correct ones) anyway and they seem OK.

Hope anyone has any thoughts? Thanks

[The Gonz]

Too bad you're in Sydney. That's the kind of problem that promises to be a cool challenge.
I can't think how that would happen unless it's some logic rather than circuit that has gone awry.
I'm going to ask it - Have you disconnected the battery for 30 minutes?

[Shambles]

^ that's a good shout Gonz

The Boring Chinese Memory module, otherwise known as the Body Control Module (BCM) ultimately decides whether the brake lights illuminate, and 30 minutes of downtime for that piece of circuitry should do it some good. Or at least, no harm.

[hyundai_i30_2011_owner]

Thank you The Gonz and Shambles (love that user name - sums up my thoughts after initially feeling quite smug I replaced the rubber coupler but then realised I had additional problems) - much appreciated.

No I haven't disconnected the battery for 30min after I put all the wiring back. I will give this a try.

[hyundai_i30_2011_owner]

Update: disconnected the battery for 30min but no difference unfortunately.

[The Gonz]

Time to explore your brake circuit. Find a fuse that, when removed, should stop your brake lights from working and look for 12V that shouldn't be there.

[Aye30]

Hi, don't forget that this is the nasty brake light switch that caused us all problems with cruise control. It has two circuits running through it, and the brake lights can work. Some people replaced the switch with a single circuit one, only to realise that their cruise control wouldn't engage. Perhaps one side of the circuit is failed?

[PhireSideZA]

Chiming in to say that brake switch issues on these cars are indeed strange. I had an intermittent ESP issue, and about a year later, traced it down to a bad brake light switch. What I did not know, at the time, was that when the ESP light would illuminate, the brake lights would stop working!

[hyundai_i30_2011_owner]

Replying to last two posts, I do have a pre-existing ESP problem (light permanently on) and as far as I'm aware the cruise control isn't working either since the rubber coupling replacement..

I'm going overseas and the wife (whose car it is) is staying behind and getting impatient. I will need to call a mechanic today unfortunately.

[PhireSideZA]

Replying to last two posts, I do have a pre-existing ESP problem (light permanently on) and as far as I'm aware the cruise control isn't working either since the rubber coupling replacement..

I'm going overseas and the wife (whose car it is) is staying behind and getting impatient. I will need to call a mechanic today unfortunately.

I think that your brake light switch is the culprit. It should be about a AU$20.00 part at most, and you can fit it yourself with 20 minutes and a 13mm (IIRC) wrench. Hopefully that will solve your issue

[Aye30]

This car falls into the switch replacement range. Hyundai i30 (September 2007 to May 2012) have you had the switch replaced?  Check on the  hyundal website with vin. You may not have to pay anything to get it replaced.