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modern car electronics 2FC / 2 !


Unkel Kunkel
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I can just about cope with old car electrics. You can see what goes where and there isn't much of it

so If it goes wrong I can struggle through.

Enter new-ish car -VW Eos 2 FSI .lovely to drive and goes like the proverbial but is so complex ,

it is as they say "2FC/2" ( Too f. clever by half ) .The folding roof is a work of art with eight hydraulic pumps heaven knows how many parts and and an electrical system of several control units and wiring that is a nightmare - and it yet it still leaks sometimes .

Anyway battery dies.Fit new one.Go away for a week, new battery flat - as in zero volts.

Recharge.Flat in 12 hours. There is a v large current drain- somewhere, but what?

Usual things checked - all OK

Standing scratching and pondering where to start fuse pulling fuses (dozens, 3 fuse boxes )

''Is that a faint buzzing noise I can hear? " .Mrs confirms there might be.

Lock up car, buzz still there.Go away for few hours - still there.

Crawl around car trying to locate it.Seems to becoming from the rear of the car, louder under offside rear wheel arch.This is Weird! Put car on ramps to try and locate.

You clever guys will have guessed it by now ,but it took me a long time to figure out it was coming from the fuel tank! Fuel Tank?

Well actually the in-tank fuel pump.It was not switching off- for days on end I suppose (I dont like to consider the fire risk or what might have happened in a crash)Pulling the apprpriate fuse, when I found it, confirmed it was the cause of the current leak.

Under the rear seat there is a little black box - 'fuel pump control module' which, in its 2FC/2 cleverness had failed, so it didn't switch the fuel pump off until the battery was deaded.

New module = battery does not go flat anymore.

 

(This is the abridged version- it took me days to figure this out - and nearly drove me crackers)

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Just pray that your EGR valve does'nt fail. I have a 2005 Golf 2.0 FSI and have had problems with the EGR valve 'jamming' By a marvelous piece of penny pinching design, you have an electric motor, fitted with a metal pinion gear, driving 2 plastic gear teeth which get weak with age and heat ( the valve body is connected to the exhaust manifold ). These gears then strip the teeth and jam the lot up. Result is that the valve jams in the wrong position and the ECU then tries to adjust the fuel/ignition settings as its being told by the Lambda sensor that there's too much carbon monoxide in the exhaust gas. So the ECU gives up and shuts down the engine  - leaving you with no power steering and very ineffective brakes. The frightening thing is that when this happens you get next to no warning or lights .This has happened three times to me now !  In this state the car usually wont start again. Sometimes bashing the valve body with a spanner might 'free up the works', but usually I end up unscrewing the lid of the EGR valve, lifting out the shredded plastic gear wheel, and replacing it in position on some good gear teeth ( the gear only rotates about 90 degrees). The car will then start and run normally until a few more thousand miles,when it happens again. I eventually had to replace the entire EGR valve as the gear was worn out completely. Needless to say - the gears are not available separately from VW - so a new valve costs anywhere between £80.00 - £250.00 depending on where you buy it from. What a piece of junk !   

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Just remove the EGR - it causes more problems than it's worth. It makes no difference to the MOT and probably improves MPG and certainly power.

Modern cars have become too clever for their own good and every 'improvement' brings another set of problems. Cars that 'read the road ahead', cars that 'anticipate your driving', even cars that correct your path as you drive... all electronics that are going to fail somewhere along the line and are not user friendly. My trusty rattle-box Mondeo broke a remote key the other day and a replacement is going to cost £135. FOR A KEY? I took the key-cutter's advice and just unlock the door manually now instead of being lazy and using a remote that never worked half the time anyway. I haven't had a radio since last June when I disconnected the battery without a code and it'll cost £££ to get it recoded. Both the car alarm and the radio code can be bypassed by devices criminals buy off the Net for £10 anyway... 

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My daily driver has a VW 2litre diesel engine. Came off motorway a while back and ping! light on dashboard flashing and car goes into limp mode. Power drops from usual 170 to probably 20 bhp. Top speed now 40ish. That was the EGR valve failed. Takes 10hours of labour to replace - subframe, exhaust transfer box and steering all have to come out.£1100 bill. Joys of modern cars......

 

Andy

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The owner of the garage which looks  after my Spitfire has some real horror stories about modern cars and the cost of repairs.......can easily exceed the value of vehicles only 3-4 years old if a major component or electronics fail. Scary stuff.

 

Andy

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I realised this some years ago when I replaced rear shocks on a Volvo at a cost of £1300.... I sold the car six months later for around £700.

The air suspension on my Discovery failed so many times that I replaced it with coil springs, and noticed no difference whatsoever to the ride experience even when towing.

I can never understand how a modern car can go into limp mode when a fuel sensor fails - a sensor that for example monitors exhaust gases and adjusts the fuel intake accordingly by the micromillimeter - surely all that will happen is that the car may run slightly richer and the planet may suffer a billion years sooner from increased emissions? It doesn't really require a breakdown miles from home - just a warning message would suffice.

I remember the time when all cars used the same components - usually Lucas! - and every garage had them on the shelf. Now absolutely every manufacturer uses totally unique components which are allegedly unavailable from anyone else. I can remember my heart sinking when they announced that the new Discovery had 16000 different parts from the previous model....

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My modern's engine has air pressure sensors. Occasionally air pressure is too much (or too little?) for one or other of them. As Colin points out it just makes a small difference to fuel consumption. But no, we have to go to limp home mode. Also down a dusty track/road, air filters clog up, again limp home mode.  So I bought a hand held gizzmo that tells me what the error is and lets me reset limp home. Works a treat well worth £30.  I leave it plugged in ready for the next time.

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Vanadium,

A newish Eos will certainly have "OBD", On Board Diagnosis, in fact OBD-2, which is more informative.

The idea is the your ECU checks and stores faults it notices, and you can retrieve them with the appropriate equipment.

 

OBD code readers used to cost thousands, but are now available for less than £20, some less than £5!    https://www.google.co.uk/#q=OBD+readers&tbm=shop

They can be 'stand-alone' boxes, or just a plug that you push into a socket on your car and communicates with your phone by BlueTooth.

 

Somewhere on your car, usually under the dash, in the glove box,  is an OBD reader socket.   In fact, on your car, it's here: http://www.outilsobdfacile.com/location-plug-connector-obd/Volkswagen-eos-1

Plug in your reader, following the instructions.

Read any faults on the device.

The more expensive ones may interpret the codes.

If not look them up on the Internet: http://www.ecutesting.com/fault_code_library.html for example.

 

This will point you to the part on your car that is faulty, or at worst is giving the ECU a hard time.

The code is generic - it's not manufacturer specific - and OBD-2 gives you more information EG "P1810       TFP Valve Position Switch Circuit/ Transmission 4-Wheel Drive Low Indicator Short Circuit To Battery"

 

The other way to trace a battery drain is to use a multimeter, set to amps - costs less £10 - start at the battery, when the car is switched off.     There should be nor more than  a few tenths of an amp flowing out, maintianing thngs like clock, radio, ECU.     As little as one amp can drain the battery overnight.  One of the most common drains is a boot courtesy light, that doesn't go off - faulty switch!

 

JOhn

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John, OBD-2. I can now connect it without looking! The instruction manual is not up to much and some guessing required as to what the acronyms mean, but I get there in the end. On occasion I have to tell the thing twice to turn off limp home, a feature of my reader, probably. Also, although the codes are universal, some readers won't work on some cars, I read a lot of angry reviews while researching which one to buy. Mine was rrecommended for my modern, but sadly doesn't work on the Triumph.

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Vanadium,

A newish Eos will certainly have "OBD", On Board Diagnosis, in fact OBD-2, which is more informative.

The idea is the your ECU checks and stores faults it notices, and you can retrieve them with the appropriate equipment.

 

OBD code readers used to cost thousands, but are now available for less than £20, some less than £5! https://www.google.co.uk/#q=OBD+readers&tbm=shop

They can be 'stand-alone' boxes, or just a plug that you push into a socket on your car and communicates with your phone by BlueTooth.

 

Somewhere on your car, usually under the dash, in the glove box, is an OBD reader socket. In fact, on your car, it's here: http://www.outilsobdfacile.com/location-plug-connector-obd/Volkswagen-eos-1

Plug in your reader, following the instructions.

Read any faults on the device.

The more expensive ones may interpret the codes.

If not look them up on the Internet: http://www.ecutesting.com/fault_code_library.html for example.

 

This will point you to the part on your car that is faulty, or at worst is giving the ECU a hard time.

The code is generic - it's not manufacturer specific - and OBD-2 gives you more information EG "P1810 TFP Valve Position Switch Circuit/ Transmission 4-Wheel Drive Low Indicator Short Circuit To Battery"

 

The other way to trace a battery drain is to use a multimeter, set to amps - costs less £10 - start at the battery, when the car is switched off. There should be nor more than a few tenths of an amp flowing out, maintianing thngs like clock, radio, ECU. As little as one amp can drain the battery overnight. One of the most common drains is a boot courtesy light, that doesn't go off - faulty switch!

 

JOhn

My account was,as I said , the abridged version...

Unless you have a multimeter that can handle a high DC current then beware - you will blow the internal fuse.

I suspected this current drain might be fairly big so put a I ohm 10 watt resistor between the detached neg batt terminal and the vehicle earth connector and instead measured the voltage drop across it.

It should be no more than 35mV .It was over 5volts and the resistor was getting warm fairly quickly so there was a proven a high current drain - and I had not zapped my multimeter.

I was about to start pulling fuses one at a time whilst watching if the voltage went down and was just pondering which of the 3 fuse boxes and heaven knows how many fuses to start on when the buzzing sound attracted me.I won't repeat the rest of the story.

 

OBD? OBD? what's that then?

Wasn't that a hit for Marmalade? Oh no, that was " Obli-dee Obli-dah"!

 

OK , I admit to be being a late and rather reluctant entry to the twenty first century but I have now arrived and stopped kicking an screaming.

Yes, the old dinosaur has been playing with an OBD 11 monitor for the last year or so and ocassionally very useful it is too. I have used it on a Freelander2, Ford C Max and yes, on the Eos.

It is an Autel DB 802 . I think It is really good and cost less than £150-.Recommended.

It can tell you all manner of clever things- the coolant temperature, engine rpm, hydraulic brake pressure , inlet air temperature and air flow; it can re rest things llike that annoying oil service light etc etc. and it can bring up and clear all sorts of codes.

But it was of no help at all in this situation(I readily admit there may have been operator error/incompetance on my part ,as I said I am a new boy)

So it was back to the old Mk 1 head scratching.

Which is why I contend modern car electronics can be 2FC/2 ..too ..ing clever by half!

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ODB is great.

My wife's car threw up a fault in its automatic gearbox. Wouldn't run in normal mode for more than 10 minutes before going into limp mode. £75 and half an hour at the dealer confirmed it was a failed low range solenoid. In the 'good old days' they'd have torn the box down costing a good grand to find the fault. ODB confirmed the 'sport' circuit in the box was still good, so she ran it around like a boy racer for a few months til I bought her a new car.

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Twelve Amps of drain??????   Wow!   You were right!   Most cheap (and perfectly good) multimeters will take 10.

That's enormous!  No wonder it killed your battery.

At least a good old Multimeter pointed you the right way, as it often can.

What was the buzzing noise?   A short, or some alarm?

 

John

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Twelve Amps of drain??????   Wow!   You were right!   Most cheap (and perfectly good) multimeters will take 10.

That's enormous!  No wonder it killed your battery.

At least a good old Multimeter pointed you the right way, as it often can.

What was the buzzing noise?   A short, or some alarm?

 

John

The fuel pump ( which sits in the fuel tank) controlled by the fuel pump control module which gone faulty ie it was not switching the pump off - even when key out and car locked up.
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