Superb 2016, Exec estate.

On my way down to Solihull recently, whilst in traffic on M6 close to Liverpool - Manchester area, I had a number of failures at the same time, Park Pilot, ABS, ACC, Front cornering lamps, tire pressure warning, hill hold. Car otherwise continued to perform normally. Carried on to Solihull. Next day plugged inOBD11 to find out what was going on, battery at 12.4 V, ignition off. Cleared all defects, and started engine, battery at 14.2 V. all defects returned. Switched off and on again a couple of times, and eventually defects stayed cleared. Left car for a few days, drove to South Wales, and on way back, all failures returned after about 170 miles of normal driving. Back a Solihull, left car for a few days, and then went to do local errand, car had 2 failures, which cleared themselves in about 0.5 mile. A few days later, I returned home to Scotland, and after starting all ok, after 200 miles or so, all failures appeared again.

I had a look at the forums, whilst in Solihull, and the suggestion is that it is the battery, getting old. I have had the car from new, and it has never had a new battery. If I have to buy a new one, thats OK, but there was a mention of resetting of electronics post battery change.

 

Question is, Is a new battery the solution, and if so what needs to be done post battery change?

 

Any advice would be most welcome.

If you found no specific fault like an ABS sensor being defective, then it probably is time for a new battery. You've done well to make it last eight years.

 

Someone will be along shortly to tell you whether the battery needs "coding" or not; this process tells the battery management system (BMS) that a new battery has been fitted and therefore the charging / discharge parameters will be adjusted to suit. The BMS will work it out eventually for itself if the coding is not done.

 

The VCDS owners map shows a couple of possibly helpful VCDS owners near you if your OBD11 can't do the coding. A five minute job.

That many erratic failure is almost likely to be the battery. You've done well that your battery has lasted that long. The car does need to be told that you have a new battery but Halfords or similar will do that for you.

That list of errors showing up has all the hallmarks of a ABS sensor failing or mis-reading the a wheel signal...........

I had the front disks and pads changed 2 days prior to the journey to Solihull. Is it possible that it may be just a poor abs sensor connection following that work?

Well, yes. I assumed that by clearing all faults you had assessed each entry as being insignificant or not relevant to your issues. Clearing faults without plodding down the list to see if there's a pattern or critical fact emerging doesn't get much closer to analysing and then resolving the problem. Rescan and see if you have anything relevant  - for VCDS address 03 ABS Brakes would be a good place to start.

 

ABS sensors can fail in all sorts of exciting ways. Fortunately they're quite cheap. If the fault persists then you'll be chasing the wiring for issues.

I cleared all faults as none of the errors came up as red, and the car was performing normally. I've been driving for over 50 years, so I was not bothered about losing abs etc. I have not really had much experience of these modern ways of doing things, so I admit that I sometimes screw up by ignoring what the car is telling me.

After your post (Inspectorman) I had a look at the obd11 results that the device emailed me, and sure enough there is a part that says that the left rear abs wheel sensor mechanical malfunction, and poor range/performance, and the left front ABS wheel sensor, magnetic field too low.

So I have had a look at buying these 2 items, and eurocarparts want £53 each, for Paget items, whereas Autodoc want £23 each for Bosch. I'm looking at the autodoc ones, they do have even cheaper ones, but I am thinking that the originals are probably Bosch. Anyone got any idea why there is such a wide variation in prices, from £10 to £53, is it just cause they can charge that amount, or is there a big difference in quality/longevity?

 

I assume that these are an easy replacement once the wheel is off.

Ecp is more expensive because they can be and have shops with rent etc and AUTODOC cheaper because it’s online only, not for all but the majority of things

 

If I’ve got things planned to do I buy from autodoc where possible because I’m not bothered if shipping takes a week or two.

Edited 21 August, 20241 yr by Danoid

There could be also various quality levels. I'd would not go too cheap on ABS sensors, if they provide incorrect/fluctuating data and/or are not calibrated properly, you might not solve your problem and be back at square one.

Also, do you have the chance to run a 'live test' to see if all sensors are registering speed and with what variations? Sometimes the problem might not be the sensor itself, but something else, like if it got dislogded from its housing, or work was done around the area and it got banged/hammered, presence of rust, and so on.

 

Actually, I'd say the reason of your electrical problems is ... Solihull 😝 Only nightmares ....🤪

 

 

Just joking 😁

 

35 minutes ago, taff_b said:

eurocarparts want £53 each, for Paget items, whereas Autodoc want £23 each for Bosch. I'm looking at the autodoc ones, they do have even cheaper ones, but I am thinking that the originals are probably Bosch. Anyone got any idea why there is such a wide variation in prices, from £10 to £53, is it just cause they can charge that amount, or is there a big difference in quality/longevity?

Mine cost €1.70 each including delivery from China, there are two types on my vehicle so I bought a few of each not expecting much of them, I fitted one to replace the dodgy sensor over 2 years ago and it is still working faultlessly.

 

VAG price is probably double what the ECP ones are, you pays your money you takes your choice, I have endured decades of know it alls (the types who will pay a main dealer £200 to fit a £1.50 component they could do in 5 minutes without even jacking up the car) lecturing me about buy cheap buy twice, and yes on rare occasions that has been the case but not to date on car parts.

 

The usual failure mode of these is the moulded in sintered magnet fracturing from an impact, either a mechanic wielding a hammer carelessly or clipping a kerb.

1 minute ago, leolito said:

if they provide incorrect/fluctuating data and/or are not calibrated properly, you might not solve your problem and be back at square one.

 

There is nothing to calibrate, they are very simple and reliable, a hall sensor activated by a magnet whose magnetic field is reduced when the castellation of the reluctor ring passes beside it changing the output state of the hall sensor.

 

If the magnet is not cracked they either work or they dont (dead on arrival) much like a reed switch.

 

 

I was mentioning because on mine RR I did had a failure on the ABS that was "fixed" by pushing the sensor further inside its housing (some sort of copper 'cage' that fits into the knuckle), which got dislogded somehow. I had a friend's D2 ABS failure due to excessive rust in the reluctor ring ...

About calibration I was drawing on "universal" or aftermarket Lambda sensor (02 sensor), which sometime provide incorrect signal and data. So you thing you've fixed the problem, but not really ...

Just to keep the OP aware sometimes is not black or white, or so easy fix ...

As you’ve had the pads and disc replaced have you checked the area since? Most likely moved something and just needs pushing back or so.

 

I had my brakes replaced once and got abs error, I’m sure they just nudged the brake dust shield back and it was okay, was my old a6 many years ago

I changed the right rear parts on my Golf recently - started with the sensor (about £7.50 on Amazon) - that didn’t cure it so had to go for the hub assembly (eBay about £25) with the ABS exciter built in.

Also had to buy a long M18 Torx socket. (£7.50)

Easy job just so long as you’ve got a serious breaker bar - that bolt is tight.

Good news. Even as low as £10 in the usual places. Your battery is still on borrowed time at 8 years - you don't want to be forced to buy one at the RAC's exorbitant price in an emergency somewhere. Save up your bawbees for a present for the car.

9 minutes ago, inspectorman said:

Good news. Even as low as £10 in the usual places. Your battery is still on borrowed time at 8 years - you don't want to be forced to buy one at the RAC's exorbitant price in an emergency somewhere. Save up your bawbees for a present for the car.

Mines also original and car registered March 2016 so probably made in 2015 and only used once a week 🫣

Edited 21 August, 20241 yr by Danoid

1 hour ago, leolito said:

was mentioning because on mine RR I did had a failure on the ABS that was "fixed" by pushing the sensor further inside its housing (some sort of copper 'cage' that fits into the knuckle)

 

Whoever "fixed" the fault by doing whatever they did was spinning you a line, they are held in place to a precise depth by a bolted flange and cannot be moved in or out without it fracturing., the copper cage exists only in his dreams as much as it would benefit from one (the sensors get seized in place by rust and usually break on removal) no manufacturer in the last 100 years has wasted money on precious metals to aid replacement of non moving parts.

 

1 hour ago, leolito said:

About calibration I was drawing on "universal" or aftermarket Lambda sensor (02 sensor), which sometime provide incorrect signal and data

 

A completely different animal and there is still no calibration involved in manufacture.

Uh, you are forcing me to admit my guilt, as the one who made the mess with the ABS it was yours truly, with my own two hands ... that is why I describe the action ☺️ Three times I had a go at it, until I got it right (this was the first time I ever did an ABS sensor).

I have to say the car is a Range Rover P38, for which perhaps many rules of the automotive world do not apply ... in fact, most of 'em 🤪

 

Here is the way the ABS sensor comes in its kit, with the bush I was referring to:

https://www.roverparts.com/brakes/sensors/STC3385/

 

Here is the way it looks when installing it from the workshop manual:

 

Anyway, my intention was not to distract from the topic, just to add that sometimes there are things that look to be super straightforward, and instead are not, so the advice was not to rush but go methodically at it. I got the Audi without working A/C, and by exclusion and many attempts I am now down at a wiring/electrical issue. If I had paid attention to the first shop I asked I would have forked out many bills for a new compressor, pressure sensors, and such, but that would have not corrected the issue ...

 

I will retreat now quietly in my hole and perish away 😁

 

 

Sorry for keep being off topic, but to close the matter above ... today I've solved the A/C issue on the Audi. Time ago, my associate (mechanic) replaced the HVAC controller as it had a failure, he wouldn't bother dissassembling it so he replaced it directly, fishing from the bin another one.

As the car was a project in waiting, I had no way to check on that until few weeks ago, when I finally got the A/C radiator and piping replaced.

The A/C panel he used is a '95, incompatible with the car which is a '97 (different compressor). Now I am looking for the right part ... he washed his hands on the issue.

Once again, never underestimate the matter at hand, especially if more hands have passed before you ... 🤪

Edited 22 August, 20241 yr by leolito
incorrect grammar

Just to bring us back on topic. Which do I go for first?

 

Change the abs sensors on the left side as per the 2 indications on the obd2, or change the battery as that would hopefully cover all of the other issues that showed up, and may also clear the abs problems?

 

I am thinking battery as a first step, as you all seem to think it is probably close to needing to be changed anyway.

 

Thoughts??

56 minutes ago, taff_b said:

Just to bring us back on topic. Which do I go for first?

 

Change the abs sensors on the left side as per the 2 indications on the obd2, or change the battery as that would hopefully cover all of the other issues that showed up, and may also clear the abs problems?

 

I am thinking battery as a first step, as you all seem to think it is probably close to needing to be changed anyway.

 

Thoughts??

My money is on the ABS exciter - not even an each-way bet, all on the nose, ABS exciter, left rear.

Exciter? Do you mean the sensor or the castellated trigger wheel?

Check it first, then abs sensor, then battery

Regardless of anything else, you need a new battery. Get one at Halfords. Drive for a week and see if all the other problems disappear.

2 hours ago, J.R. said:

Exciter? Do you mean the sensor or the castellated trigger wheel?

The ring with the magnets in - I assume it’s also called a ‘trigger wheel’ maybe?

Either way, the problem is you can’t see the condition of the part unless the hub is removed - at which point you’re kinda committed (not least the one time use compression bolt) and a new hub assembly may as well be fitted - also, when the hub is off the sensor probe is accessible because getting ‘em out invariably results in part snapping off.

Edited 23 August, 20241 yr by Berisford
Addition.