Battery Change / Coolant Sensor / Spark Plug Replacement Part 1

[cover99]

Gents I suspect my battery has given up and have ordered a replacement.

Has anyone used a memory saver before during this change process to maintain settings and Navigation plus/Radio to prevent having to input radio code? Thoughts?

If you have were these providing power through the OBD port or accessories plug/cigarette lighter.

Also is there a how to input the security code to the RNS-D audi nav plus/radio

Thanks again in advance of any advice.

Steven

[TOPMAN]

Hi Steve

I replaced my battery a week ago, consulted the Audi ELSA manual, but nothing special or of concern. From memory the RNS-E radios will work just fine after a battery disconnect as they communicate with the instrument cluster. On my S6 with RNS-D I always needed the code which you can find in the owners manual. If not you can get the code from online sources, but deal with that bridge if necessary later.
I personally recommend Varta for car batteries (I think they were OEM) or Yuasa, but they are a bit pricey. The Varta website offers 2 options for our cars. I bought the AGM battery as it has 30 more cranking amps which is a good thing here in winter. It now spins up the starter motor like a scolded chicken! Best purchase I’ve made this year not sure why I struggled with the old one for so long LOL

https://www.varta-automotive.com/en-gb/ ... ines=18033


Sent from my iPhone using Tapatalk

[ALE-RS6]

Swapped mine out for a Varta battery a few months ago and had no issues. Highly recommend.

https://www.tayna.co.uk/car-batteries/varta/i1/

However, mine had no head unit in when I replaced the battery. Purchased a second hand RNS-E after replacing the battery and had to input the code once on the first screen. I haven't disconnected the battery since installing the radio. Worst case, you can buy an unlock code online if you haven't got yours to hand. My code was written on top on the head unit also but normally in the RNS-E/D book if you have it.

[Felix2566]

I've had the battery disconnected many times and had no issues with the RNSE after reconnecting.

[cover99]

Hi all appreciate the feedback so far. I cannot confirm the original battery fitted in 2004 being Varta but certainly the last one from Audi was from this brand Craig. Pictures attached of the battery currently in position.

I have ordered a Varta battery so await delivery. As it is the RNS-D I have I suspect i will loose the radio code. The previous owner provided the code but knowing my luck that's why I was considering a memory saver as an option.

Has been a strange one. Car is parked up on a ctek conditioner. I always turn it over as do not like the engine sitting static for too long. On trying to start i got dashboard lights as normal but nothing not even a click from the starter, Checked the conditioner and only 3 shown. Did a battery refresh via ctek and showed about 5 on it. Tried a start and ran but rough, and lumpy not firing on all 8 and again only 3 shown on ctek so thinking battery. Switched off quickly in advance on a replacement battery arriving. Will keep you all posted.

Does this impact an MRC remap when changing the battery if I loose power?

Steve

[Shoppinit]

If you’re worried about losing the code, fix some wires to the positive and negative terminals and use an auxiliary battery to keep the car powered while you replace the battery. As soon as you connect the auxiliary disconnect the main battery as current may flow from one to the other depending on the relative states of the charge.

[cover99]

Cheers Ben will fashion a couple of leads to enable a feed from another battery during the change over.

Steve

[cover99]

Hi All, The good news is the battery change went well. No issues with loss of codes etc.

Ignition to position 1, normal lights on dash. Both fans start to run (Which is not normal), small one on passenger side and the large on on drivers side. Both sound to be running full.

Car turned over and initial fire up a success. However after a few seconds started to run rough. Stopped and checked CTEK trickle charger which showed 3 on charger, lower than i would expect. (This could well be normal) Voltage on dash looks okay. I started to wonder if a fan is going to ground? Although tfans are old car has only done 42k miles so thought they would have many more revolutions and cannot understand what both would continue to run and start every time ignition to position 1.

Left for a couple of hours and CTEK back to full, Ignition to position 1 and both fans start, checked charger and back at 3. To be honest this is not something I would have checked in the past.

Managed to access the supply connector for the large fan from below and disconnected this. Repeated the test at ignition position 1, Large fan did not start, as I expected, small fan full speed no matter what econ mode is selected in the car to and the charger shows 3 on its display. Did not try to turn car over with the large fan disconnected.

All other functions as normal, lights, Central locking, radio, windows.

1. Has anyone had an issue / Symptoms like this before?
2. With ignition at position 1 both fans run without starting the car. (Could be totally unrelated but also a coincidence)
3. Initial symptom with original battery - No turn over at all. / Fully charged original battery, Lumpy on start up / New battery, Fans on, start up normally for a good few seconds back to lumpy tick over.
4. I cannot seem to see the supply connector for the small fan seems to head up from fan rather than down like the large one, Do you know where this is located? is it accessible? (I can guess the answer to accessibility)
5. For my information can someone confirm the cooling function for the large and and small fan. I thought Coolant temperature "Large one" and Air con "small one"?
6. I had seen this issue with the fans starting ramping up and down shortly after starting car. This has now developed to going at full even in position 1 and will continue to run for a short time on switching ignition to position 0.

Unsure of the next steps to take and any advice would be greatly appreciated. A rather depressed C5 RS6 owner

Steve

[Shoppinit]

What CTEK is it? Different models have different meaning for the indicators. On mine, most of the charging happens on 3 and 4. The fans use a lot of power. Wouldn't surprise me much if they significantly drained the battery after a relatively short amount of time without the engine running. From memory, both together use about 1kW which is a LOT of amps.

Concerning the fans both coming on full at start, I would check the coolant sensor to see what temperatures it's sending. You need to check both outputs from it. One to ECU and one to HVAC. Different circuits.

You can also use the Vagcom to test the fans individually to see what they are doing.

Put the AC in ECON mode to see what happens.

[111marc111]

I had similar with the both fans running at full chat occasionally including after switching engine off they would run on at full speed for a few mins occasionally.
Cant remember the exact code but it pointed me towards the coolant temp sensor.
Fitted a new one and problem vanished.
From memory it's a two part switch that supplies temperature info to the ecu and also temperature info to the dash cluster. So although the temp gauge on the dash might be reading OK as mine was, the sensor could still be faulty.
They are quite cheap and not too hard to change.

[cover99]

Hi guys thanks for coming back to me. The CTEK is an MXS 5.0.
I have tried the Econ button both illuminated which I believe to be aircon off and light off which i believe to be aircon on. With no difference to the fans, albeit only the small fan running now with larger disconnected at electrical plug.
Battery now back at 7 on the charger after dropping to 3 with when ignition put to position 1, but not started.

I think I have located the electrical connector for the small fan - Under the cover for the power steering. Do you think it would be worth disconnecting this and leave the large fan disconnected also then give it a try again starting the car?
I am going to order a coolant sensor hopefully still available from Audi,
1. Could I confirm the part number is 059 919 501A and does this include the o-ring and clip?. If you know if its NLA (Not available LLL Parts) please let me know what is the preferred brand.
2. Can this be replaced without draining the coolant

I held off purchasing the Ross-Tech https://www.gendan.co.uk/product_VCV23.html due to my lack of computer skills and fear i would do more damage than good with it, but will get this ordered and will thank you all in advance of my cry for help when trying to use it.

Steve

[111marc111]

Coolant sensor can be changed without losing too much Coolant. Certainly doesn't need draining.
It's a pain to get to and will need the airbox off but it is possible.
I didnt use genuine just a reputable brand. Mine came with the clip and oring. Which is a must as the original clip snapped on removal for me.

[Shoppinit]

Tons of VAG cars use the same sensor so you won’t have a problem sourcing one.

[steve2003rs6]

Just a tip someone gave me when I changed my sensor last year.
Tie a piece of very thin cord on the clip before you try to fit it. I used sewing cord off a cotton reel. About two foot of cord hanging loose. If you drop it you can easily retrieve it otherwise you will probably lose it.
Once the clip is fitted snap or cut the cord off.

Dropped mine twice trying to fit it. Without the cord it would have been lost.

Ps. I didn’t drain any coolant. Hardly any loss of coolant.

[cover99]

Thanks again all. New sensor now on order, I went for original VW/Audi item for this time. Appreciate the tips on attaching the thread to the clip, i am sure it will be required with my shaky hands which seem worse when working on the car.

Any other tips on the intake removal/MAF disconnection.

I plan to remove everything over coming days then await delivery of the sensor.

Steve