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Land Rover Garage Wolverhampton

How to solve and Audi A3 Error Code!

Unless you are an engineer or mechanic, I am not sure we can fully appreciate how every little aspect of your Audi has its own function and responsibility.  It’s everything working properly and in time.

But let’s be completely honest, when most people buy an Audi A3 the criteria is performance and kerb appeal.  But the intricate parts of the engine can ruin both these criteria in an instant.  Without them all working properly, the car doesn’t run as it should.

Don’t get me wrong.   Most people have really no interest in how the engine works, how may nuts and bolts are in there, or even how Audi use Vorsprung Durch Technik.  And maybe that naivety means that they just expect to get in the car at any stage and it work perfectly.

Until one day, you start the A3 as usual and …

Audi EMS, DPF, Error codes, warning lights, car not running properly… HELP!

This was what we experienced recently with a client of ours.  They brought an Audi A3 (2016) to us after the vehicle started to display the error code P2458 – Diesel Particulate Filter – Regeneration Duration.

The DPF is a little-known filter that traps particulate matter such as soot and ash from the exhaust, which if not maintained/replaced regularly, it can cause huge and expensive problems within your engine.  The filter has been standard since 2009 and luckily we work with these on a daily basis at Fitch Autos.

The client brought their Audi A3 to us after noticing the error code, sparking more warning lights to appear on the dash board and the cars performance was “limp” at best.  Being a trade client, they were aware of the need to regenerate the DPF, but every time they tried, it was unsuccessful.

What made this interesting was that the client had already taken the car to the main Audi dealer, who had completed a full software update.  But still, error codes, warning lights, etc….

Now for the technical bit…

The testing confirmed the DPF error code and the data feedback confirmed the Audi A3 diagnosis of DPF regeneration.  All filters have a process of self cleaning and emptying, this being called regeneration on a diesel engine.

So, we knew at this stage we had to check the DPF and check its levels.  The next step was to check where exactly the problem lay.

The DPF has passive and active regeneration. Passive being when the Audi A3 is driven at high speed, the temperature of the exhaust burns off the soot particles which are built up in the filter.  But this relies on the car being driven at 70mph+ for extended periods.  But if like most people, driving at the speed for a long time will be 5% of your driving experiences.

So cleverly, active regeneration is built into the Audi engine and means that when soot builds up in the filter to around 45%, this will cause the exhaust to heat up in order to burn of those particles and clear the filter.

This process relies on the correct information getting recorded at all the various sensors, all the way from the exhaust to the engine.

So what did we do different?

When the Audi A3 arrived with us, the first thing we did was check the Audi Service & Repair history.  Everything seems to have been checked and double checked.  With nothing jumping out at us from this, we turned to the dealer diagnostic tool ODIS to have a look at the live data on the car.

We started with checking the soot levels.  We noticed these were not above the DPF threshold and the filter was not blocked.  So next, we check all the car filters and realised that the car oil level was way too high and diluted.

After draining the excess oil, we attempted the regeneration process again with ODIS.

The heat up process was not happening…. This was the problem.  We tested exhaust temperature sensor and this showed to be not working in the turbo phase.  As mentioned earlier, there are several sensors on the Audi A3 which run from the exhaust to engine and we need to test them all.

We also had to test all the wiring to establish which one part wasn’t working and why.
Using our expertise of Audi cars and with DPF error codes, we were able to locate the problem quickly.  We found it!  The Exhaust Temperature wasn’t working, stopping the regen process.

So then we fixed it!

Knowing the problem, we were able to replace the temperature sensor, along with an oil and filter change.  This allowed us to re run the regeneration process of the DPF.

No time was wasted and we were able to get from full diagnosis, to having the car fixed and handed back to the client within a day.

Being able to hand back the car fully functioning and running better than ever, is something we work at every day.

Speed and reliability

If you are an Audi owner and have been experiencing performance problems with your car, please contact one of our expert Audi technicians where we would be happy to offer advice or book you in for a vehicle assessment.

Our assessment are designed to identify the problem as quickly as possible saving you time and money, and getting you back on the road and enjoying your car.

Call us on 01543 452 630Save money on Audi servicing