Need help with making sense of numerous failure messages that came all at once

[JGO]

Hi,

may I kindly ask your support and guidance with the situation I am facing?

 

Octavia III 1,2 TSI, 2005, ca. 65000 km, owned from new by me and the car has been absolutely trouble free up to now.

 

• I changed from winter to summer wheels
• When starting the car afterwards and driving I got the following messages:
  tire pressure warning (that was correct, as I had not stored new settings after the wheel change). So I stopped and stored the settings
  ABS/ESC failure
  tire pressure again
  AFS failure (cornering light)
  Start/stop failure
  Light on the button for the parking sensors is blinking
• Stopped the engine, waited and tried again with unchanged results.

 

While I could imagine that I might somehow have done something to a ABS sensor during wheel change (even I did not touch them, not even the cables and have done wheel changes countless times), most failure messages did not seem to have any connection to the wheel change. I suspected a battery problem and measured voltage at the terminals: 10,1 V which is obviously very low.

I had the battery over night connected to a charger. This morning I disconnected, waited for 5 min and measured 10,36 V, which seems to indicated a ca. 50% charged battery.

 

The battery is still the original so no reason to complain that it seem to have reached end of its life.

 

Are all the failures I gut indicated consistent with a faulty battery or should I suspect anything else?

 

Thank you in advance

 

 

[Breezy_Pete]

Charge it more and see if the faults stop showing.

I guess you meant to type 12,1 and 12,36 V.

 

[JGO]

Hi Pete,

thank you for your reply. You are absolutely right, it should have been "12" before the comma in both cases not "10". Unfortunately there does not seem to be a possibility the edit/correct my original post.

I am not optimistic that more charging will bring the battery voltage any higher, but it still may.

 

However, when driving, the alternator should produce something above 14 V and that is when the errors show up....seems strange but my knowledge is limited

[Breezy_Pete]

You might be surprised if you monitor the alternator output voltage; recent cars with start/stop have a different charging strategy which includes deliberately keeping the battery a little below fully charged. You may see lower voltage than you expect much of the time. It's better for fuel economy than it is for battery lifetime.

 

If you have a charger, use it to help your diagnosis, rather than jumping to possibly premature conclusions.

[MarkyG82]

Also assume it's a typo with 2005? Should it be 2015? If so at 7 years old it could easily be end of life for the battery. I'm sure the consensus on here is roughly 5 years for these modern stop/start batteries.

[PetrolDave]

1 hour ago, Pete_Ex-Wino said:

If you have a charger, use it to help your diagnosis, rather than jumping to possibly premature conclusions.

Much of the electronics is very voltage sensitive and the battery management system will turn loads off to protect a battery in poor condition.

 

Having said that, if a battery charge doesn't solve the problem then I had a similar set of faults last year on a 2015 Octavia which turned out to be a failed right rear speed sensor - best to get a fault code scan done rather than jump to conclusions.

Edited 22 April, 2022 by PetrolDave

[Breezy_Pete]

Thing is, if you just replace a battery at the first sign of any electrical trouble, you have to pay for the battery, and possibly coding the control systems to it. Then you might find a few weeks later that there is a charging system fault, a parasitic current drain, or another fault such as the one you mentioned Dave, none of which will have been improved at all by the battery swap.

 

So you'll end up spending more than necessary, and potentially even immediately degrading the new battery, depending on the nature of the problem.

 

 

[MarkyG82]

@Pete_Ex-Wino of you are right. Does seem to be an issue that gremlins occur with a depleted battery. However that doesn't remove the need for proper diagnosis (and repair) of source issues. I was merely passing on what I had seen from other users.

For what it's worth I disabled stop/start on my Octavia for much of the 3½ years I had it and was still working fine when I re-enabled it before sale. It was over 6 years old at the time so goes against my battery age theory.

[Breezy_Pete]

1 minute ago, MarkyG82 said:

so goes against my battery age theory.

Not really; using start/stop seems very likely to shorten a battery's life compared to not doing so. 

 

[ords]

8 minutes ago, Pete_Ex-Wino said:

Not really; using start/stop seems very likely to shorten a battery's life compared to not doing so. 

 

It's always seems to be the luck of the draw with batteries. Mine is 9 yrs old and I've always used start/stop.

[Breezy_Pete]

@BigEjit tells us that the design life is ten years on AGMs not sure if same applies to EFBs. That precludes any 'usage accidents' such as letting the battery into a deep discharge state for whatever reason. Would it be fair to say yours has avoided such accidents thus far @ords? What's your usage pattern like (annual mileage, journey types) if you don't mind me asking out of sheer curiosity?

[JGO]

Thank you to all for the valuable input. Again, I am ashamed and sorry for the typos (yes, the car 2015 not 2005). Too bad that I am not able to edit the post...Anyway, should probably have waited til after first coffee until typing....🙄

 

I have a simple and some years old OBD-reader which is supposed to be for VAG vehicles. Used on a Fabia with success earlier but never never on this Octavia. I connected it and despite several attempts, it was not able to communicate with the car.

 

The assumption that the battery is toast after 7 years seems reasonable. While the car was earlier used almost daily, during the pandemic it stood for weeks on end also in winter which hardly did the battery much good. Even if there might be other issues (which I don't hope), putting in a new battery might be a good idea anyway.

 

I do not think there is a parasitic drain. Over Easter the car was parked for 7 days and when I started it at about 5 degC ambient, all went well.

[PetrolDave]

4 minutes ago, JGO said:

I have a simple and some years old OBD-reader which is supposed to be for VAG vehicles. Used on a Fabia with success earlier but never never on this Octavia. I connected it and despite several attempts, it was not able to communicate with the car.

 

Even if there might be other issues (which I don't hope), putting in a new battery might be a good idea anyway.

That old OBD reader likely isn't compatible with the CAN bus only diagnostics of the Octavia III.

 

If you do fit a new battery then don't forget to code the battery management system so it knows you have fitted a new battery, otherwise it will still assume the old battery is fitted and still be likely to turn off some systems. If the battery is the same capacity and type all you need to do is change one digit in the serial number field.

Edited 22 April, 2022 by PetrolDave

[JGO]

"If you do fit a new battery then don't forget to code the battery management system so it knows you have fitted a new battery, otherwise it will still assume the old battery is fitted and still be likely to turn off some systems. If the battery is the same capacity and type all you need to do is change one digit in the serial number field. "

 

That's good to know, thank you Dave! Would you mind to educate me where and how the serial number can be changed?

I should get the new battery tomorrow and will fit it during the weekend.

[MarkyG82]

You'll need a code reader that has more to it than the usual cheap ones used for just reading codes. Usual options suggested on here are VCDS or OBDeleven. Former needs some sort of computer (laptop) and is more expensive to start with. Latter is cheaper and wireless via a phone app. Arguably not as powerful but able to do 99% of what a home timkererererer needs.

 

Unless you can find a local to do the coding you might want to wait till you have access to the required coding equipment before fitting the battery. May not make a difference but I wouldn't want to be doing too many journeys like that in fear of damaging the new unit.

 

Edit: there is a section on this forum of people who have vcds and are willing to share the love usually for a beer or 2. Cheaper than a garage and you get to nerd out with a fellow car nut.

Edited 22 April, 2022 by MarkyG82
Vcds coding people

[JGO]

I got the new battery on Saturday and had it connected to a charger until Sunday just to be sure.

I read in the workshop manual what to do when changing the battery and followed the advice. Mainly the following seemed important:

• When installing the new battery, first connect the terminals to the cars cables, then reconnect the plug for the Battery Monitoring System
• If the old and new battery have identical specs, no coding is needed (in my case both are AGM, the old is rated 68 AH, the new one is 70 AH which I believe is close enough)
• At first start the following is to be expected: "After connecting the battery and switching on the ignition, the warning light for the stability programme TCS/ESC and the warning light for the power-assisted steering remain lit. The warning lights go out automatically after driving a few metres forward. Thereby the steering angle sender - G85- is activated"

Unfortunately this errors did not clear. I drove for about 5 km, stopped 2 times and switched off completely. I will order a decent code reader (thinking of the Foxwell NT530) to investigate further.

[PetrolDave]

4 hours ago, JGO said:

If the old and new battery have identical specs, no coding is needed (in my case both are AGM, the old is rated 68 AH, the new one is 70 AH which I believe is close enough)

That's not the whole truth, if you don't change the battery serial number the BMS will assume the old battery is still fitted and will still try to manage it as such (possibly including load shedding) - after some time (several hundred miles has been mentioned) it will 'twig' that a new battery has been fitted and start learning the new battery characteristics. Changing the serial number will start that relearning immediately.

[JGO]

That is interesting to know, thank you Dave!

I have now ordered the the code scanner and hope to get it within a few days.

I still have these errors:

• ABS/ASR
• Cornering light (sometimes)
• Can't store tire pressure setting
• Parking sensors don't work

 

Those seem so unrelated and the fact that it all started when I changed from winter to summer wheels makes it all more strange to me. 😕

[IndomitableSnowman]

Are all of the summer tyres the same make/model and same level of wear? I'm thinking of differing circumference triggering an ABS sensor fault. The ABS sensor signals are used a wide range of other systems.

[Ootohere]

You fit your wheel /tyres, reset the TPMS and even if the tyre pressures are all a bit different maybe even a spare of a slightly different size is fitted, or different sized pair front and rear are fitted and the system does not have a flaky. 

[JGO]

Thank you for your valuable input!

The summer wheels I fitted are the ones which the car came with from the factory when new (rims and tires). Wear is practically the same on all four.

I checked and adjusted tire pressure on all wheels after fitting them. All that would suggest that the wheels do not cause the trouble.

 

However, before driving for the first time after wheel change I forgot to set the tire pressure monitoring and got an error. So I stopped, set the TPMS and drove on. I would not think that this would upset the system.

Now I get TPMS warning every time I drive, but the system does not allow me to set the TPMS.

 

I am rather confused.

 

[PetrolDave]

Sounds to me like the code scanner will most likely show a problem with a wheel speed sensor - all of the systems showing an error need to know vehicle speed to operate correctly so a faulty wheel speed sensor IMHO is the most likely root cause.

[Titanium_Man]

I would also be pulling out the cornering light as a intermittent warning for that could be that the bulb is on its way out. Look to see if there’s a smidge of blackness on the bulb. Worth the free check. 

[PetrolDave]

1 hour ago, jars said:

I would also be pulling out the cornering light as a intermittent warning for that could be that the bulb is on its way out. Look to see if there’s a smidge of blackness on the bulb. Worth the free check. 

Don't forget that the cornering lights only operate up to a certain speed, so if there is a problem with the speed signal from the ABS then the cornering lights will be disabled.

[JGO]

I begin to understand that indeed an ABS sensor fail might actually be the cause of all or most of the errors I am seeing. Waiting for my scanning device to arrive and hope to conclusive answers from it.

 

Again, thank you all so far 😀