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BMW Service Wolverhampton

BMW 1 Series High Pressure Fuel warning – error code 11A002 fixed

Here at Fitch Autos, we work with all problems big and small, to get our clients back on the road as quickly and safely as possible.  We’re not just mechanics, but problem solvers.

So when a client arrives with his BMW 1 series and says “My car is cutting out and I don’t understand why” we are ready to use our experience and knowledge to solve the problem.

The client told us that he had already replaced some parts and it still wasn’t working…  

OK, we need to go back to the beginning and find out what is happening with this BMW 1 series

How did the problem start?

The client told our BMW specialist technician that he had noticed when he was out driving the vehicle, after about 20-30 minutes, the BMW 1 Series would lose power and then completely cut out.  Nothing at all and no warning.  Annoyingly dangerous!

The BMW would restart but only once the car had completely cooled down.  Annoyingly unpredictable as well!!

With no way of knowing when or why the car was going to cut out, the client knew he had to get the issue sorted as soon as possible.  Making sure his BMW 1 series is back on the road safely.

The fix

Once the vehicle was in our garage, the client advised that they had already replaced some parts on the BMW 1 series but the problem of cutting out was still there.  The parts the clients had already replaced were:

  • The In-tank Fuel Pump
  • The Fuel Rail Pressure Sensor
  • The High Pressure Fuel Pump

The above parts had already cost the client over £1500 and the car still wasn’t working.  The client was definitely going to benefit from a technical evaluation.

Evaluating the problem at Fitch Autos

At Fitch Autos, we don’t believe in guessing or swapping out parts in the hope of getting lucky and resolving the issue – this can prove expensive and time consuming, whilst still not getting to the root of the problem.  That’s why we use our proven 15 step diagnostic process to track down the fault – only replacing or repairing what we need to.

Having access to official BMW guidelines means we could create a rigorous test plan to leave no stone unturned.  Getting to the root cause of the issue fast.

We carried out a full evaluation using an oscilloscope, retrieved error codes and inspected serial data.  The error code retrieved was:

  • 11A002 – High Pressure Fuel, Plausibility, Pressure too low 

Next, we knew that because this was an intermittent fault, we needed serial data.  We needed to road test the BMW to work out when it cut off.  The road test also allows us to monitor live data from the car’s engine management computer.

With the car running, we were able to complete the initial checks to the low pressure fuel system.  All our checks confirmed that the low fuel pressure pump and all the associated wiring was in good condition, working with no faults and concerns.

We were also able to confirm that whilst the vehicle was running as it should, the desired and actual fuel pressure were within the manufacturer recommended guidelines and therefore nothing at fault.

And then just as the client said, after 20-30 minutes, the power went and now we had something to get our teeth into.

But with our comprehensive understanding of the serial data, we were able to capture all information we needed to diagnose the fault.

A faulty power supply

During our serial data analysis, we found that when the BMW started to fault, the 12v supply to the fuel pump was lost.  It had been present up until this point, so here is where we needed to investigate further.  Also, we confirmed that having let the car cool down again, the 12v supply was fully restored to the fuel pump…. so it must be a heat thing.

Our expert technician then followed the official BMW documentation and found the 12v feed for the fuel pump and noticed that it came from a relay.  We stripped it back to access the relay, and then we tested the relay to check if this was the issue.  

We found that the relay was breaking down and faulting when warm.  This explains why the issue only occurred after a prolonged driving period.

Why Fitch Autos for your BMW fix?

As a BMW specialist garage, we have access to genuine BMW parts, technical information and data which means we are expertly placed to maintain the integrity of your vehicle.

Our specialist BMW technician was able to replace the faulty relay straight away.  Then we cleared error codes and took the BMW 1 series on an extended road test to make sure the issues had been fully resolved.  And as the engine warmed, the car continued to drive perfectly.  

At Fitch Autos we pride ourselves on achieving a ‘first time fix’ – we know that our customers’ time is precious. No one wants to keep returning to their garage time and time again to resolve an issue with their BMW. At Fitch Autos, we understand that.

No unnecessary parts replaced. No unnecessary return visits. Safe motoring. Quality workmanship. Value for money.

Fitch Autos has an expert team of technicians who are here to help.  Our evaluation process is key in finding uncommon, less obvious faults within your vehicle.

If you would like our help, contact us today and we can get your vehicle in front of our experts, as soon as possible.

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