[Mateyevans]

G'day, I have an i30 Auto GD D251E 08/2013~03/2017 PETROL 1.8 litre. I just recently replaced my rotors and brake pads. I returned the brake calipers back in with opening the break fluid cap instead of bleading the brakes. Most people on YouTube recommended doing this way. After a little while the traction control light came on and the car went into limp mode. I checked it again a bit later and everything was good again. It came on and off a few times then the engine light came on a couple of times. Every time I drove the car every was good but after a few minutes the traction and engine lights would come on. I checked the brake fluid reservoir and it had risen to the top and took some out. Now sometimes the engine light is on without the traction control light on. I don't know if it's a wheel sensor on something more serious. The brake pedal is a tiny bit Spongy so I thought of bleeding the brakes, but again I'm worried it's more serious or I screwed something up

[TerryT]

Hi, I'm not a mechanic/tech which is probably why I'm having trouble understanding the sequence of events with the traction and engine lights coming on and off and any relationship to your recent brake work (doubtful)...but I am curious about your brake rotor and pad replacement. 

1. When you said: I returned the brake calipers back in with opening the break fluid cap instead of bleading the brakes. .  Do you mean you returned the brake caliper pistons back in (i.e. pushed the pistons back into the calipers to allow room to insert the new brake pads)? 

2. And, is ...opening your brake filler cap... the same as opening the brake master cylinder by removing its cap? 

If it's Yes to both questions above, I'd have to say that removing the brake master cylinder cap is normal practice so you can more easily monitor how much brake fluid is being pushed back up the brake line into the master cylinder by the pushed-in pistons.  An un-capped master cylinder also allows, if needed, to quickly syphon out any excess brake fluid as you are doing the job. 

But I have never considered just removing the master cylinder cap as a replacement for actually bleeding the brakes from the caliper brake bleeder screws to ensure there is no dirty brake fluid and/or air bubbles still in the system.  You mentioned "Most people on YouTube recommended doing this way".  I'm always up for learning new things, can you provide a YouTube link?

[Mateyevans]

Yes I was pushing them back in for new brake pads. First time I've done it this way. Sorry it took a bit to get back to you, just figuring out how to reply. The link is

[TerryT]

Yes I was pushing them back in for new brake pads. First time I've done it this way. Sorry it took a bit to get back to you, just figuring out how to reply. The link is

Ok, after watching that YouTube video I understand a little better what you were trying to say.  Removing the cap off the master cylinder (shown at 13:28 in the video) is purely to more easily monitor/control the fluid level in the master cylinder during this work and let you syphon off excess rising brake fluid or add new fluid, as necessary.  It does not constitute bleeding the brakes of old fluid or air in the brake lines.

(I am surprised in the video that he didn't show the master cylinder more times as the brake fluid level, imo, would have risen a little and it certainly would have after the second wheel was done). 

You said in your first post: "...with opening the brake fluid cap instead of bleeding the brakes."  If you only followed that video, you have not bled your brakes, at all.  Probably why the brake pedal felt a little spongy.

I wouldn't have thought the brake work you did would have contributed to the dash traction control/engine light issues you are getting unless possibly, maybe your braking performance is ridiculously low (and you'd know that) or you managed to say, damage the ABS sensor (I don't know how close that would be to your brake work area)...but I'm happy to be proven wrong.    

I'll leave the issue of the dash lights and limp mode etc to the tech gurus here.

[TerryT]

@Mateyevans. Keep forgetting to ask you, have you had the car scanned (with an automotive scan tool) to identify any fault codes?

Needs a code reader putting on it before you do anything else to see what codes have been flagged up. I've just flushed all the brake system on my 2013 as I don't think it's ever been done, the fluid was pretty dark, I replaced it with Comma dot 4 ESP fluid.

[Aye30]

I use a v-gate obd2 with torque(lite). It can see most of the usual trouble codes, but cannot see ABS or airbag info. It cost me about $15 many years ago. What ODB2 setup are others running?

Bluetooth ELM327 with forscan, torque and car scanner.

[BrendanP]

I've replaced discs and pads on my i30s about 8 times without any problems like that. I loosen the cap on the brake fluid reservoir when pushing the caliper pistons back in, and siphon fluid off if it's getting close to overflowing. I did have a Rover 75 where it recommended opening the bleed nipple on the caliper for the fluid to drain out as the piston is pushed back, but that's the only time. I've never had to bleed the brakes afterwards unless it coincided with the fluid renewal interval.

Could it be the wheel sensors were damaged or misaligned when replacing the discs?

[TerryT]

I've replaced discs and pads on my i30s about 8 times without any problems like that. I loosen the cap on the brake fluid reservoir when pushing the caliper pistons back in, and siphon fluid off if it's getting close to overflowing. I did have a Rover 75 where it recommended opening the bleed nipple on the caliper for the fluid to drain out as the piston is pushed back, but that's the only time. I've never had to bleed the brakes afterwards unless it coincided with the fluid renewal interval.

Could it be the wheel sensors were damaged or misaligned when replacing the discs?

I agree, you can do a brake rotor and pad replacement without having to do a brake bleed.  When Mateyevans first posted saying: I returned the brake calipers back in with opening the break fluid cap instead of bleading the brakes I misunderstood his meaning, hence my comments about brake bleeding because I personally do a quick brake bleed with every change of rotors and/or pads.  Just my way of doing things, fuddy duddy.    

[Aye30]

Hi again, with multiple codes i.e. esp off and check engine light at seemingly the same time, first check battery condition and connection. Computers do funny things when not given enough power.  Then common reasons for esp off light are steering angle sensor, abs/wheel speed sensor fault, one tyre smaller than others (flat or bald) and a faulty brake light switch. If all the brake lights don't come on or there is a delay between the high mount and normal brake lights, then your switch could be faulty. I belive SAS can be reset by turning the steering wheel lock to lock, but some have had to get dealer level tech to calibrate.  As for the engine code, that will need to be scanned. Anybody doing their own repairs on cars should have a code reader as a diagnostic tool, because paying Supercheap auto aprox $30 to scan codes may not always be an option if the car isn't running.

[Mateyevans]

G'day, sorry it's taken a bit to get back to everyone. I did find out about Supercheap doing BDO2 scanning. Tried to get it done yesterday but there scanner was almost flat and wouldn't work. Went there again today and had it all ready and didn't charge me for the hassle of going there for it twice, which was nice of them. This is the first scan before clearing faults.

[Mateyevans]

Here's the second scan after clearing faults.  Most times I check the car in the morning everything seems fine, after driving for a ,little while it happens again, one time I saw the traction control light flash than stay on and go into limp mode. The next day everything was ok and tried it again and this time I saw steering light flash and traction control light stayed on and went into limp mode

[TerryT]

Here's the second scan after clearing faults.  Most times I check the car in the morning everything seems fine, after driving for a ,little while it happens again, one time I saw the traction control light flash than stay on and go into limp mode. The next day everything was ok and tried it again and this time I saw steering light flash and traction control light stayed on and went into limp mode

To clarify something.  After your car was cleared of faults and then re-scanned today at approx. 2.27pm, have your problems resurfaced since then?

[TerryT]

Hi again, with multiple codes i.e. esp off and check engine light at seemingly the same time, first check battery condition and connection. Computers do funny things when not given enough power.  Then common reasons for esp off light are steering angle sensor, abs/wheel speed sensor fault, one tyre smaller than others (flat or bald) and a faulty brake light switch. If all the brake lights don't come on or there is a delay between the high mount and normal brake lights, then your switch could be faulty. I belive SAS can be reset by turning the steering wheel lock to lock, but some have had to get dealer level tech to calibrate.  As for the engine code, that will need to be scanned. Anybody doing their own repairs on cars should have a code reader as a diagnostic tool, because paying Supercheap auto aprox $30 to scan codes may not always be an option if the car isn't running.

@ Aye30.  A helpful reply.

You said: "...or there is a delay between the high mount and normal brake lights...".   Would you advise what a "high mount" is in car brake-land.  Is it to do with the brake pedal height?  (When I was a young man, a "high mount" was usually met with a firm "No!" by the ladies.  ).

[Aye30]

On the rear of the FD and GD, there is a third brake light mounted high in the center  above the rear glass. Some times in the rear spoiler (if fitted). The brake switch in our FD had a recall, as one side of the 4 pin swich was faulty or the wrong switch type was installed at the factory.  Common issues presented as, cruise control would not engage, esp off light would light up and the side brake lights and the third high mount stop lights could behave differently. Some would have a delay, i.e one would come on the moment you pushed the brake and the other might come on a few seconds after, if at all. I know the FD was affected, and the replacement switch  part number covers 2007 to 2013.

[Aye30]

Hi, does this car have aftermarket led bulbs installed in the positions indicated by short to ground ?

[TerryT]

On the rear of the FD and GD, there is a third brake light mounted high in the center above the rear glass. Some times in the rear spoiler (if fitted). The brake switch in our FD had a recall, as one side of the 4 pin swich was faulty or the wrong switch type was installed at the factory.  Common issues presented as, cruise control would not engage, esp off light would light up and the side brake lights and the third high mount stop lights could behave differently. Some would have a delay, i.e one would come on the moment you pushed the brake and the other might come on a few seconds after, if at all. I know the FD was affected, and the replacement switch  part number covers 2007 to 2013.

Yeah, that was my second guess! .   Seriously, thanks for the detailed explanation, appreciated. 

[Mateyevans]

G'day, yes the problem came back again, and in the morning everything's fine. But after about 10 minutes it would happen again. And I checked all the light bulbs and found the two front interior light bulbs were led.

[Mateyevans]

G'day, I flushed out the old brake fluid with some new. The old fluid looked a dark colour, It was easy to see the new fluid flow through cause the old one was so bad. I have no idea how old the fluid was. Old brake fluid may have been the start of the problem cause I've done a bit on the fault code C0002 TCS Control Channel "A" Valve 2 (Subfault). It's the ABS control unit has a electronic fault internally and has to be replaced. Maybe pushing the brake fluid backwards might have finished it off with the old fluid already damaging the unit. That old brake fluid could of been half water for all I know, it looked bad

[Mateyevans]

Here's a link to page that helped me understand the fault code

https://www.troublecodes.net/ccodes/c0002/

[TerryT]

G'day, I flushed out the old brake fluid with some new. The old fluid looked a dark colour, It was easy to see the new fluid flow through cause the old one was so bad. I have no idea how old the fluid was. Old brake fluid may have been the start of the problem cause I've done a bit on the fault code C0002 TCS Control Channel "A" Valve 2 (Subfault). It's the ABS control unit has a electronic fault internally and has to be replaced. Maybe pushing the brake fluid backwards might have finished it off with the old fluid already damaging the unit. That old brake fluid could of been half water for all I know, it looked bad

Given the uncertainty of the old brake fluid's history and its appearance, your diagnosis on what caused the ABS failure may well be correct. 

That old brake fluid could of been half water for all I know, it looked bad. .  I really hope you were speaking figuratively.   To give you context 3% moisture content in DOT 4 rated brake fluid reduces the fluid's boiling point from 230C to 170C degrees.  And, 4% moisture content reduces that to 155C.  DOT 3 brake fluid is a worse performer.  My street/track STi on AP660 fluid with 3% moisture is rated to boil at 205C, a big difference in the real world.
________________________________________________

Just for giggles: So, one can change brake fluid say, every two years or you can monitor the moisture content of your fluid with a ridiculously expensive, high quality, accurate tester...or you can buy a much cheaper, less accurate conductivity tester which is maybe, sort-of close enough.
 
No prizes for guessing what I have in my garage.  Yep, both of them! (And, more).

The OTC tester uses a 12V battery (usually the car's battery) to heat up a small sample of the brake fluid to boiling point (usually from the master cylinder reservoir) and then displays that boiling point on the screen, which is compared to the boiling point of the DOT X fluid being used.



The conductivity Tester: Remove the end cap and place the exposed two prongs into the brake fluid.  Tool LEDs light up to indicate the fluid's moisture content, supposedly.

[TerryT]

Here's a link to page that helped me understand the fault code

http://www.troublecodes.net/ccodes/c0002/

@ Mateyevans.  Hmm, C0002...an interesting and likely expensive code going off the link you provided: "...the electronic failure indicated by trouble code C0002...cannot be repaired reliably.  The only reliable remedy for this code is the replacement of the ABS control unit, which requires that the replacement ABS control unit be programmed and integrated into the vehicle’s electronic systems."  Ouch!

You said in an earlier post: Maybe pushing the brake fluid backwards might have finished it off with the old fluid already damaging the unit.  Ok, long story first...Some mechanics will say a vehicle with a properly maintained and serviced brake system should be able to withstand the occasional, small brake fluid push-back up the line when the caliper pistons are pushed back into the caliper to allow room for say, new brake pads. 

Other mechanics (let's call them the 'purists') will say you should never do that as whatever crud/contaminants in the brake fluid sitting behind the pistons will be pushed up the brake line and may wind up in the ABS module, with the risk of Murphy's Law striking.  (The brake fluid behind the brake cylinder pistons is the lowest point in the system and it draws whatever crud/contaminants are formed in the system over time, plus that fluid is more heat-stressed because it is closer to the braking action of the pads/rotors/calipers). 

The 'purist' mechanic will attach a clear, nylon tube to the relevant brake bleeder screw, crack open the bleeder screw and push the caliper pistons back into the caliper.  The old/dirty/cruddy brake fluid sitting immediately behind the caliper piston will be expelled through the plastic hose, into a container and the bleeder screw tightened.  Some will even clamp the brake line near the caliper (using a proper brake line clamp, not a vyce grip) to make sure no brake fluid can be pushed back up the line.  FYI, you can clamp normal oem flexible 'rubber' brake lines but not the more expensive braided steel reinforced [race] brake lines as their inner tubing does not bounce back into shape after releasing the clamp.  Ask me how I know.

When I was regularly playing with brakes many years ago with mates, we would carry out piston push-backs using both methods, it depended on what the guy whose car it was, wanted.  I personally liked the 'purist' way but when regularly using the non-purist way for about 8 years on two 2006 Subaru STi's we didn't get one C0002 code...but brake fluids were bleed or changed regularly, so maybe not a fair comparison.

Ok, the short story: Mate, in your case, I would hazard a guess that your old brake fluid had too much crud/contaminants/nasty bits in it for over too long a time and Murphy's Law finally struck in the ABS module.  It is one plausible reason, anyway.

Please keep the forum updated on what you do to fix this issue.

Have you checked all the ABS sensors to make sure they're in the correct position, the wiring is intact?
Also check the ABS rings as they can throw up fault codes for the ESP, ABS etc

[TerryT]

Have you checked all the ABS sensors to make sure they're in the correct position, the wiring is intact?
Also check the ABS rings as they can throw up fault codes for the ESP, ABS etc

Yes, all good suggestions .  Aye30 and myself had mentioned checking ABS sensors though I didn't think of the ABS rings.

As I understand it, the problem with Codes is that they don't, in fact, always identify the actual problem item but instead identify a good starting area in which to diagnose-test-troubleshoot. For example, the Code here (C0002) seems to say you need to replace the ABS control module(?) when the  problem could be one that is solved by related (and cheaper) solutions that, say, lPGNI30 has suggested.

I haven't done much code reading on my Hyundai yet so not exactly sure how it works, done a fair bit on Ford's.
An example is my lads old car, 2014 Fiesta ST threw a load of codes, around 14,some for the instrument cluster, radio, battery, a couple for ABS and a couple for ESP and the fault was? A dodgy wheel bearing, work that one out, 👍
Essentially the wheel was moving about enough for the ABS sensor to not register the ABS ring, fixed by a garage then a month later the same codes popped up, the hub nut had not been torqued and damaged the threads on the CV joint, had to put a new driveshaft in as we couldn't find a CV joint at the time and yes, I torqued the hub nut up properly.

[TerryT]

@ Mateyevans.  Hmm, C0002...an interesting and likely expensive code going off the link you provided: "...the electronic failure indicated by trouble code C0002...cannot be repaired reliably.  The only reliable remedy for this code is the replacement of the ABS control unit, which requires that the replacement ABS control unit be programmed and integrated into the vehicle’s electronic systems."  Ouch!

You said in an earlier post: Maybe pushing the brake fluid backwards might have finished it off with the old fluid already damaging the unit.  Ok, long story first...Some mechanics will say a vehicle with a properly maintained and serviced brake system should be able to withstand the occasional, small brake fluid push-back up the line when the caliper pistons are pushed back into the caliper to allow room for say, new brake pads. 

... Mate, in your case, I would hazard a guess that your old brake fluid had too much crud/contaminants/nasty bits in it for over too long a time and Murphy's Law finally struck in the ABS module.  It is one plausible reason, anyway.

Please keep the forum updated on what you do to fix this issue.

@ Mateyevans.  Did you identify the problem?