Car Battery Replacement - Coding?

[metzer_001]

Hi,

So yesterday after work my car failed to start, I'm pretty sure its the battery as the MMI gave a low battery warning a few weeks ago. I left the car for 15 mins before trying again and the car started. The battery level meter on the MMI did show around 20-30% however accurate that reading may be. My cars a 2011 S5, and I assume is running on the same battery from new.

Regarding a new battery, I've read conflicting reports on whether the battery needs coding via VAG-COM upon changing. ( https://www.audiforums.com/forum/b8-models-72/audi-a4-b8-battery-coding-176172/)

Has anyone got first hand experience of replacing the battery? Must it be coded via VAG COM or can I simply skip that step. A local Audi specialist quoted me 250£ fitted, using the OEM battery. A quick look at Halfords brings up a price of £130 plus £15 for fitting. However I doubt Halfords would code the battery (if it does need coding).

I didn't even realise that the battery in these cars is under the spare wheel in the boot, I wonder if I could use jump leads to start if need be? It looked as though I would have the undo the metal top cover of the battery to get to the +/- ends.

Edit - car started fine this morning, I'm trying to not use any heating / radio etc to conserve battery whilst I get this sorted.

Second Edit - If it did need coding, would only the OEM battery work with the car? I.e Could I code a third party branded battery?

Cheers folks

 

[RAF_S7]

Jump starting points, for cars with batteries in the boot, are still located under the bonnet.
These are usually somewhere near the firewall, and usually covered with plastic trim (marked with either a battery symbol or a big “+”) On my 7 they are located next to the firewall on the drivers side. On some models there is only a +ve jump terminal. For negative you use either the engine block, or similar exposed metalwork.

New batteries should be coded in order to maximise the battery recharging capacity. On modern Audi’s, with all their smart electronics, the system reduces the amount of charge applied as the battery aging characteristics change. Coding resets the battery characteristic on the control system so that it learns the new battery from scratch.

You do not need to replace the battery with another Audi battery!

YouTube is your friend

 

[Dadar]

Just to add that if you change your battery you will need to code it as RAF S7 said but all you need to do is change 1 digit in the serial number using VCDS and the vehicle will see that as a new battery.
I have just done this personally and can assure you that it works 100% as I was not prepared to pay the dealers price.

 

[metzer_001]

Hi All,

Just to update, so yesterday a similar issue happened as Wednesday where after a short journey, a little while later my car did not start. Pushing the key in (which normally starts the engine) did nothing, no response. Engine didnt even tick over. You can hear some sort of electrical noise when u push the key in though, for about 5 seconds. MMI battery meter showing 10%.

So I booked my car in today at a local independent Audi garage who I usually use . I asked for a battery change and also for someone to look into what else could be causing this issue. They ran diagnostics etc which came back with quite a few errors (i guess a low battery flags up all sorts) and they changed the battery. Here's the interesting bit. The mechanic did say that they did multiple engine stop starts to confirm the issue was fixed, and everytime the engine started fine except one time. They then plugged in diagnostics but no errors codes were found (they cleared the ones from before, I have a copy)

By now its the end of the working day, so he asked me if I want to take the car or leave it with them over the weekend, as he wanted to look further into it on monday. I did say if it throws up any codes i'll just bring the car back next week. So I go collect and pay. The mechanic did say it could be something to do with the actual ignition in which cause may have to take it to Audi worst case scenario.

Literally within 5 minutes of driving back home, I get a gearbox malfunction error saying NO REVERSE, and only gears 1/3/5 were allowed by the gearbox. I decided to pull over in a local tesco just to stop the car, and hopefully the error disappears so i can have all my gears back! As soon as I triedto start the engine, same issue as before! Engine not starting at all, not ticking over (as in the churning noise when you can actually hear the engine trying to fire up, cant hear anything like that) Only this very faint noise when I push the key in to start the engine, like something is trying to do something.

This was less then 5 mins of leaving the garage which were closing. I give them a call and explained the situation. They said to bring the car in on Monday and they would have to further look into it, sounds like some sort of electrical issue but would need further looking into. I decided to give the car 10-15mins whilst I went into Tesco, came back to the car, and first time the engine fired up. I drove home making sure I don't switch the engine off.

Got home, turned off engine, tried again 5 mins later, exact issue - engine not starting, not ticking over no nothing. Just that weird noise. Battery level on MMI 100% (new battery installed).

Several hours later now I try my car and it fires up fine! Went to shell to fill up, no issues there. Got home, did multiple engine off engine on starts and engine started up fine each time.

Carista just flagged up 01315 - Transmission Control Module

Which I assume is that gear box error from earlier (which has since disappeared). No errors about these ignition issues. Would appreciate any input from any technical Audi folks here (all suggestions welcome!)

What could be causing this sudden ignition issue / engine not starting?

Thanks

Edit - just so its clear, my car doesnt have the keyless start, I need to physically push the key into the slot and push to start.

 

[Dippy]

Well I would suggest that you had a genuine battery problem and needed a new one. Whilst indeed a bad battery can cause all sorts of other issues as ECMs lose power, these ought to go away once the battery is replaced. Unfortunately it seems that you have a second problem, and likely a gearbox one.

You undoubtedly know that this gearbox has a history of problems so I'm sorry to say that it is likely you have encountered one of them. I do find it strange that you found a TCU DTC when the garage did not, especially after they checked diags following a start failure. From my reading most of the gearbox problems are either harsh changes (2 to 1 for example), or selection problems (exactly like you have seen) and are usually down to mechatronics, either the whole thing or a PCB, or a gear selector sensor. But yours seems to be mostly that the engine refuses to start. I can imagine (but don't know for sure) that a TCU problem could be such that the ECU is not confident about the state of the transmission and hence refuses to allow the engine to start. But I would expect that to throw a DTC. Are you confident that the garage has proper diags and not just relying on Carista?

The bottom line is that this needs a full diag check. Carista has given you a code but you need the details behind it.

 

[metzer_001]

Hi Dippy,

So its not so much the gearbox I'm concerned with as it has flagged up in the past and disappeared again. I can confirm that the gear box error has vanished now.

To clarify, the Audi Independent Garage have the proper diagnostics computer, Carista is what I have.


Same issue happened this afternoon whilst I went gym. I got there fine, car was okay. After an hour, the car again refused to start. I filmed a short clip on my phone which I will try to link here. However I drove around in the morning to a few places and car was fine, no issues with the engine turning.

The strange issue is this refusal of the engine to turn/start doesn't throw up any error codes. The garage said that during their multiple engine start stop tries, the engine refused to start one time out of 10 times. However no error codes were thrown when they checked - they needed more time to investigate but as it was Friday 5pm I said i'd come and collect the car as I needed it for the weekend. The mechanic did say it could be an ignition issue in which case I may have to go to Audi dealer worst case.

So in the past few days, when I broke down, I assumed it was the battery, and whilst the battery was definitely low and needed changing, when i tried to start the car, the engine didnt even turn over when i pushed the key in to start. Would I have expected the engine to try to turn and start at least, if the battery was flat?

Just ran Carista and the following appeared: I will clear all codes and see if anything is triggered when the car next refuses to start.

OBD2 - pending:
P0417 - Secondary Air Injection System Switching Valve "B" Circuit Shorted

Central electronics:
01496 - Bulb for Fog-Lamps, Left (L22)

Front passenger's door:
00920 - Heated Outside Mirror (Z4/Z5)

ABS:
01315 - Transmission Control Module (TCM)

Engine:
09499


Fingers crossed this won't end up costing thousands !


Edit - here's a short clip I recorded today when the car refused to start:
https://natalia.infra.cloudconvert....16a0a2620751590804147f8f5f28547b6c065ec7e9e9b

Let me know if download doesnt work, will try upload on youtube or somewhere else otherwise,

Thanks

 

[Dippy]

I have to admit I have no real insight. When I have previously read cases where there seem to be a lot of seeming unconnected errors, it has been because of a low battery. Now that you have a new battery but still have starting problems perhaps there still is an issue somewhere in the power management? I assume the garage did actually test the original battery and confirm that it was bad? The P0417 code doesn't quite make sense. Low voltage problems usually produce general comms and implausible signal errors, whereas shorted seems rather specific. Unfortunately Carista simply does not give the info you need, including exactly when the error occurred and if it was isolated or repeated. Looks like you'll have to rely on the garage to diagnose this.

 

[RAF_S7]

Dead batteries can throw up all sorts of gremlins.

Do you know anyone with VCDS, or maybe you can shout out for someone local to come run a full scan, followed by a save of all codes and a full clear of any stored codes?

Carista is ok, but it’s not as good a diagnostic tool as VCDS.

The link to your video clip doesn’t seem to be working, for me anyway.

And new batteries may not be fully charged if they have been sitting on a garage shelf....

John.

 

[metzer_001]

I have to admit I have no real insight. When I have previously read cases where there seem to be a lot of seeming unconnected errors, it has been because of a low battery. Now that you have a new battery but still have starting problems perhaps there still is an issue somewhere in the power management? I assume the garage did actually test the original battery and confirm that it was bad? The P0417 code doesn't quite make sense. Low voltage problems usually produce general comms and implausible signal errors, whereas shorted seems rather specific. Unfortunately Carista simply does not give the info you need, including exactly when the error occurred and if it was isolated or repeated. Looks like you'll have to rely on the garage to diagnose this.

Dead batteries can throw up all sorts of gremlins.

Do you know anyone with VCDS, or maybe you can shout out for someone local to come run a full scan, followed by a save of all codes and a full clear of any stored codes?

Carista is ok, but it’s not as good a diagnostic tool as VCDS.

The link to your video clip doesn’t seem to be working, for me anyway.

And new batteries may not be fully charged if they have been sitting on a garage shelf....

John.

I understand Carista may not give me the same diagnostics as VCDS or whatever the garage uses. My new battery does show on the MMI that its maximum charge - I may have to take the car on a long drive just to help it charge. May have to dig around here to find someone local to me if the problem continues.

The problem seems intermittent because I've been using my car this weekend on multiple trips and only one time the engine failed to start. Straight after, what I did was take the keys out, put foot on brake, insert key, foot still on brake and then push key to start engine. Engine started fine.

I didn't think foot had to be put on the brake before putting key into slot? I've never done that in the past year I've owned the car. Engine was fine on the way to work today. Will be keeping a close eye on it, and taking my car back to the garage this week for them to have a look over.

Managed to come across other posts on forums of Audi's that also have failed to start in a similar manner to mine - engine not cranking. Compiled a list of their solutions, will take these with me to the garage.

ignition switch relay
clutch, flywheel and clutch assembly, (although mines auto so this may not apply??)
Start Relay / Solenoid
Wiring harness from battery to ignition? (Something along the lines of this, can't find the exact forum post)


Edit - Will get myvideo uploaded again properly this evening

 

[metzer_001]

Here's the video of the issue:



Engine started fine throughout today, very weird. Above video was taken on Saturday just gone, stranded at my gym!

 

[RAF_S7]

If the battery was “dead” I wouldn’t expect to see any response from the instrument panel. Also you don’t get intermittent dead batteries, so I would rule out the battery as the root cause of the problem.

The starter never engages when the fault is present, so I would rule out any mechanical issues related to the engine.

That leaves an electrical issue associated with the starter circuit, which could be a few things:

• Ignition switch
• Anti-theft immobiliser (including key, key battery or key present/sensing controller)
• Brake light switch
• Auto gearbox sensor switch (prevents starting unless in P or N)
• Starter solenoid (Any clicking sound when trying a failed start?)

Difficult to pin it down further without either VCDS or dealer diagnostics......

 

[CHEZ]

I would put my money on the brake switch.
On my B7 it was pretty easy to swap.
Sorry I can't comment on the B8, but as a guess would be similar
My mate at work has a RS4 B7, and when his cruise control went wonky, was down to a fault with the brake switch.
Just to clarify, it is always something daft, particularly with electronics and sensors that cause the havoc.
Good luck

 

[metzer_001]

Many Thanks John + Chez , gives me something to take back to the garage with.

I don't know if its the same in all Stronic Audis regarding the brake pedal, but as soon as I sit in my car and put my foot down on the brake, there is alot of movement - i.e pedal goes all the way down. Now If I take my foot off the brake and let the pedal come back up, and now try it again, the brake pedal only goes about half way or less, compared to the first attempt.

Is this normal behavior or something related to the brake light switch? Car will be going down to the Audi specialist tomorrow so will keep this thread updated. Hopefully the car does fail to start whilst its there, as its very intermittent. Car was fine all day yesterday until 8.30pm in the evening when I decided to fill up some petrol!

• Starter solenoid (Any clicking sound when trying a failed start?)

During a failed start, there is a very low very faint noise that lasts for about 3 seconds. Difficult to know where exactly its coming from but I think perhaps the top hinge area of the bonnet just in front of the driver.

I should also mention that I always start the car when in P.

 

[CHEZ]

The brake switch is literally just a switch, a button technically.
It would not necessarily affect the throw and stroke of the pedal in a mechanical way.
I was referring to the switch being faulty can have a knock on effect to other electronics if that makes sense.

 

[RAF_S7]

Many Thanks John + Chez , gives me something to take back to the garage with.

I don't know if its the same in all Stronic Audis regarding the brake pedal, but as soon as I sit in my car and put my foot down on the brake, there is alot of movement - i.e pedal goes all the way down. Now If I take my foot off the brake and let the pedal come back up, and now try it again, the brake pedal only goes about half way or less, compared to the first attempt.

Is this normal behavior or something related to the brake light switch? Car will be going down to the Audi specialist tomorrow so will keep this thread updated. Hopefully the car does fail to start whilst its there, as its very intermittent. Car was fine all day yesterday until 8.30pm in the evening when I decided to fill up some petrol!



During a failed start, there is a very low very faint noise that lasts for about 3 seconds. Difficult to know where exactly its coming from but I think perhaps the top hinge area of the bonnet just in front of the driver.

I should also mention that I always start the car when in P.

I would not expect the brake pedal to go all the way down when stationary with the engine off. Normal behaviour is usually maybe half way on the first press, but getting harder with less travel on the 2nd/3rd press etc, as the vacuum assist will not be present if he engine is not running. Brake pedal travel is not controlled by the brake switch, so I would ignore this for your intermittent start fault - but as an aside if you feel the brakes are inefficient normally, you may want to have them checked (issues would have been highlighted on last MOT if present)

The faint noise is probably the fuel pump priming when you first insert the key, which only lasts a few seconds.

Assuming your Indy garage has the right diagnostic kit, there will hopefully be some stored fault codes which will point them in the right direction.

Good luck!

 

[Dippy]

Mine is far from that description. Before I start the engine the pedal moves a bit, and then when I start the engine it feels firmer. Mines a 2015 but I still wouldn't expect such a difference to be due to facelift changes.

 

[metzer_001]

So my cars been with the garage all day yesterday. They said it seems to not start when the engine / car is warm (which explains why leaving the car for a certain period seems to fire up the engine). Not sure why this would be though?

Garage used a tool that measures the voltage in binary values and traced the power between the battery, starter motor and alternator. They compared the readings to when the engine was starting to when the engine wasn't working. They're 90% sure its the starter motor but as you cant visually see it (apparently only the back end is visible in the S5) under the car to tell whether its fully oxidized or wiring damage etc that leaves the 10% of uncertainty.

Quoted approx £900 for a new starter motor part and labour. Deciding whether to get them to do it or if its worth going to a regular garage (non Audi specialist) and getting a quote from them (maybe a bit risky for an S5? Apparently the A5 and S5 is a fair whack different underneath the car, starter motor is easier to change on non S/RS cars)

I don't think the starter motor was throwing any error codes though, is that normal?

 

[RAF_S7]

I don’t think the actual starter motor is “smart enough” to provide any specific codes.

The S5 engine is definitely more complex that the A5, so the cost premium is to be expected (unfortunately)

How confident are you with the capabilities of the garage you used? (Have you used before, had them recommended etc.)

£900 is a lot to pay for only a 90% chance of fixing the issue. That missing 10% is a lot of wriggle room, should the issue not be fixed, and you end up paying for troubleshooting by part replacement - at your cost!

The first thing I would do is shop around for a replacement starter, to benchmark the costs. Starter motors can be repaired (or exchanged) but it’s really down to how long you can be without a working car far.

 

[RAF_S7]

Just had a quick look on Europarts.

A recon starter motor is under £180.

I would be inclined to purchase a starter motor, and find a quality garage to fit. You could also ask the forum Parts Request for a replacement price.

That starter solenoid looks like it’s available separately. Parts diagram here

 

[metzer_001]

I don’t think the actual starter motor is “smart enough” to provide any specific codes.

The S5 engine is definitely more complex that the A5, so the cost premium is to be expected (unfortunately)

How confident are you with the capabilities of the garage you used? (Have you used before, had them recommended etc.)

£900 is a lot to pay for only a 90% chance of fixing the issue. That missing 10% is a lot of wriggle room, should the issue not be fixed, and you end up paying for troubleshooting by part replacement - at your cost!

The first thing I would do is shop around for a replacement starter, to benchmark the costs. Starter motors can be repaired (or exchanged) but it’s really down to how long you can be without a working car far.

The garage I've used has many good reviews, its a proper Audi Independent Specialist. Its been authorized by Audi for servicing (so still counts towards full dealer service history). Its probably not that much cheaper than Audi themselves though.

Luckily I can be insured on another car whilst mine gets repaired. Yes as you say £900 is definitely alot when there's a 10% unknown element. The mechanic did say to me that in all his years of experience, he can't think of anything else which could be the issue.

I've attached the latest diagnosis indicating their voltage tests they did. The mechanic did say the voltage is going to the starter but it's just not firing up. Only when the starter motor is cold will it fire up without any issues.

https://ibb.co/d6X51vt

Thanks for checking out the parts, I've also just had a look on ECP, there is a Bosch starter motor for £173.99 but they charge £72 on top, which is refunded when you send your old part back. Any hazard with buying a reconditioned unit though? Even though ECP would probably refund a faulty stater motor, I would be paying the labour to install it, and then to later remove the part...

Thanks buddy.

 

[RAF_S7]

As long as the reconditioned part is reconned by a reputable company, there should be no issues. Any recon part should come with at least a 6 month warranty anyway, especially from a recognised source/parts supplier.

You can save even more £ by going the eBay route here

£900 still sounds a lot to me for a starter motor change on the 3.0 engine (it is 3.0, not 4.2 right?)

You would probably save £££ by buying a recon starter (or new) and paying a non specialist garage to change the starter motor for you. Couple of hours on the ramp maybe....

The replacement solenoid only, is probably £50. I’d be inclined to just change that part initially, since your not hearing the solenoid operate when you try and start.

 

[RAF_S7]

Reading the print out, my first reaction is that 11.374v @ 1381 rpm is really low....

I would have measured the voltage:

• Across the battery with engine off, then across the battery at engine idle, to check for correct charge voltage from the alternator
• The switched 12v ignition feed to the starter solenoid
• The 12v feed to the starter motor

If they haven’t done that, then the chances of the fault being in that 10% unknown, increases......

Think about posting a new thread, specifically for S5 starter motor problems. You may get more feedback from members who have had similar issues. Your current diagnosis is getting lost in the battery coding posting...

 

[Dippy]

FWIW I agree that T30 measurement looks low - it should be close to alternator voltage. Also if when the car starts it does so fine, then it implies that the motor is good. Similarly it also suggests that the alternator is too, otherwise the battery would be getting low and this would be noticed. It does seem to point to the solenoid switch. If you can wait then get them to replace that first?

 

[metzer_001]

The replacement solenoid only, is probably £50. I’d be inclined to just change that part initially, since your not hearing the solenoid operate when you try and start.

Would the labour cost still be high for this? Or is the solenoid location different to the starter motor?

Reading the print out, my first reaction is that 11.374v @ 1381 rpm is really low....

I'm not sure exactly how they measured the voltage but I will inform the next garage. What should a 'normal' voltage reading be with the engine running? I thought it was around the 12V mark give or take..?

Also if when the car starts it does so fine, then it implies that the motor is good. Similarly it also suggests that the alternator is too, otherwise the battery would be getting low and this would be noticed.

The mechanic did he could be the brushes within the starter motor, which get overheated / knackered when its overheated. Which could explain why the car starts when cold/left for a while. He said the power was going to the starter motor, so there was no reason it shouldn't fire up. No faults were being thrown because the signalling in the circuit thinks everything was fine.

I think its good to get a second opinion of another mechanic. From what I've seen online, this sort of problem has happened more on S and RS cars compared to 'standard' models of Audis.

I will start up a new thread in the coming day(s).

Cheers guys.

 

[RAF_S7]

Would the labour cost still be high for this? Or is the solenoid location different to the starter motor?

Probably similar. The solenoid is attached to the starter motor, so still a starter motor out job.

I'm not sure exactly how they measured the voltage but I will inform the next garage. What should a 'normal' voltage reading be with the engine running? I thought it was around the 12V mark give or take..?

I would expect anything between 13v ~14v with the engine running.

This video will help you understand



The mechanic did he could be the brushes within the starter motor, which get overheated / knackered when its overheated. Which could explain why the car starts when cold/left for a while. He said the power was going to the starter motor, so there was no reason it shouldn't fire up. No faults were being thrown because the signalling in the circuit thinks everything was fine.

Bad brushes are possible, but I wouldn’t expect it to cause intermittent starting, it would be bad all the time.

I think its good to get a second opinion of another mechanic. From what I've seen online, this sort of problem has happened more on S and RS cars compared to 'standard' models of Audis.

May be worth trying to find an auto electrician, rather than a general garage. You can ask for recommendations in the forum.

I will start up a new thread in the coming day(s).

Cheers guys.

 

[metzer_001]

Update,

So my cars been in the garage the last week or so. They also found the fault was due to the starter motor. A new OEM starter motor was fitted. I'm not sure what the exact issue was with the starter motor but I will try find out when I collect the car.

Another thing the garage found was the engine bay mounts were cracked (one moreso than the other). The badly cracked one was leaking oil. So I have also asked for that to be replaced too (200£ approx for the OEM one). You can see the crack in the black rubber area of the mount. The mechanic said it helps to absorb the vibrations from the engine, if I plan to keep the car he'd recommend changing.

Hopefully have my car back by the end of the week. Full service due in the next month or two also. Will need to remind myself why I bought an S5!

 

[CHEZ]

Update,

So my cars been in the garage the last week or so. They also found the fault was due to the starter motor. A new OEM starter motor was fitted. I'm not sure what the exact issue was with the starter motor but I will try find out when I collect the car.

Another thing the garage found was the engine bay mounts were cracked (one moreso than the other). The badly cracked one was leaking oil. So I have also asked for that to be replaced too (200£ approx for the OEM one). You can see the crack in the black rubber area of the mount. The mechanic said it helps to absorb the vibrations from the engine, if I plan to keep the car he'd recommend changing.

Hopefully have my car back by the end of the week. Full service due in the next month or two also. Will need to remind myself why I bought an S5!

The starter motor!!
Glad you got it sorted and shared your experience with us.
One question though, do you use start stop (if equipped) at all?

 

[metzer_001]

The starter motor!!
Glad you got it sorted and shared your experience with us.
One question though, do you use start stop (if equipped) at all?

No start stop in my B8 S5. I'm not sure if its even available in the B8 or B8.5 S4/S5.

I would hate to have start-stop with those issues I've just had, end up leaving car on road and catching an uber !

 

[MuPPeT_ON_TouR]

I have it in my 2014 S5 B8.5.. I thought it was standard fit.

 

[metzer_001]

Oh okay maybe its just the B8 then. I've always thought start stop was for increasing fuel economy etc, hence for the S / RS models it wasn't required.

 

[Dippy]

Start/stop was standard on the B8.5
That "increasing fuel economy etc" is not optional, its mandatory along with emissions, and likely the reason why the new 2019/20 S5 has a diesel engine.