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Discussion Starter · #1 ·
Ive just been recovered by the AA (top recovery) off the motorway after the van just lost power and coasted to a halt.
No loud bangs or knocks or dash lights.
The AA man plugged his diagnostic thing in and couldnt get any readings.
This is as far as he could get.....
'Will crank over and run but no throttle operation- low pressure pump working, NO on board diagnostic codes stores on vehicle-on live reading.
No movement on throttle percentage reading and will not allow access into all systems'
Please can shed any light on what could be causing this??? before I have to fork out hundreds on diagnostics:(
thanks.
 

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Discussion Starter · #5 ·
sounds like and airflow meter or air in fuel/blockage.
can you bypass the fuel filter head temporarily to isolate that
The AA bloke checked the fuel and pressure and that was fine, Not sure about air-flow meter tho??

He reckons it might be a faulty crank sensor or throttle sensor,as these can cause the symptoms ??
 

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Discussion Starter · #6 ·
Im purchasing a vagcom lead and basic software to try and retrieve the error codes myself before going any further.
Does anyone know where I can find out what the error codes mean or will this be avalible on the software?
Thanks.
 

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Do T5's have fly-by-wire pedals or is there a cable? may be a stupid question but if it's fly by wire has the pedal sensor come unplugged or stopped working?
 

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Discussion Starter · #10 ·
Do T5's have fly-by-wire pedals or is there a cable? may be a stupid question but if it's fly by wire has the pedal sensor come unplugged or stopped working?
Yeah the t5s seem to have fly by wire everything,
Im not sure the sensor has come unplugged, I would look but wouldnt know where too.
Also the engine will fire up and tick over at 1000rpm for a second or two and then stall.
Hopefully the vagcom lead will be at home when I finish work.
 

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On a petrol injected car if it fires for a couple of seconds and stops it usually means an induction problem. For example the TPS or Air flow meter readings are wrong, or there's a very large air leak in the "metered" air.
You can get the same symptoms if you remove the throttle body and metering system completely just leaving the inlet manifold. Sorry to be so broad but I've never worked on diesels!
 

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Discussion Starter · #12 ·
Ok I have made some positive progress.

I recieved the VAGCOM lead and software and loaded it on my laptop (eventually!!)

On the first scan for fault codes it found this.....


16486- mass air flow sensor (g70) signal too low

p0102-000- intermittent.


So Ive looked up the code and it says this:-

16486/P0102/000258 - Mass Air Flow (MAF) (G70): Signal too Low
Possible Symptoms
Probably no serious malfunctions
Loss of power
Possible Causes
Wiring and/or connections (short circuit?)
Mass Air Flow (MAF) (G70) defective
Possible Solutions
Check wiring and connections
Check / Replace Mass Air Flow (MAF) (G70)
Special Notes
In MY 1995-2002 (?) in Europe at VW-diesel-cars G70 had the bad reputation of slowly losing his performance, causing loss of power. It's not a matter of defective or breaking down, but it is filthy / dirty (not easy to clean). You can check functionality by making a log in [01-engine], [meas.blocks-08], group 003 (3e gear, full throttle, from 1700-4000rpm)

What I want to know would this stop the van from firing up and running as I can just get it started but it wont stay running for more than a second or two.

I even tried disconnecting the air mass meter plug from the meter and tried to start the engine with no luck. Would this work ??? cause it made no difference!

I retested with vagcom and all the tests after the first one came back with no fault codes :confused:

Any ideas as I dont want to fork out on an air mass meter if it makes no difference.
please help me arghhhh :)
 

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Hi tufty, it won't be the the MAF because that doesn't match your symptoms, disconnecting it means the ECU uses an average or best guess to run the fueling. So if you saw no difference it won't be that. (It will cause a fault code though!)

Have a look at the live data. To do that open the engine controller, then 'Measuring blocks'. Scroll to '002'. You will see one of the fields is marked 'Load', this is throttle position. At idle it should read 0% and as you slowly press the pedal to the floor you should see it climb smoothly to 100%. The throttle position sensor shouldn't really cause cutting out though.

The fact yours runs for a few seconds is odd. How long exactly would you say it runs for? It's quite critical because immobilizer faults can cause cutting out just after starting but that would be no more than say, one second max before it died.
 

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Discussion Starter · #14 ·
Hi tufty, it won't be the the MAF because that doesn't match your symptoms, disconnecting it means the ECU uses an average or best guess to run the fueling. So if you saw no difference it won't be that. (It will cause a fault code though!)

Have a look at the live data. To do that open the engine controller, then 'Measuring blocks'. Scroll to '002'. You will see one of the fields is marked 'Load', this is throttle position. At idle it should read 0% and as you slowly press the pedal to the floor you should see it climb smoothly to 100%. The throttle position sensor shouldn't really cause cutting out though.

The fact yours runs for a few seconds is odd. How long exactly would you say it runs for? It's quite critical because immobilizer faults can cause cutting out just after starting but that would be no more than say, one second max before it died.
Hi thanks for the reply, Good job you reckon its not the air mass meter as I was just about to spend out £125 quid on one!

When i turn the ignition to start the engine it fires up and revs to about 1000rpm for 1-2 seconds. It then cuts out. If I try to start it again it splutters and wont start!

Would my van have an immobiliser?? Never used it or is it built into the engine management systems etc.

I only have the limited VAGCOM software for code retrival etc but I will look when I get home tonight.

One more thing is AA man tried the throttle response thing and got no readings, But he couldnt even get his software to run on my t5 to start with.
 

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Your van does have an immobilizer. It recognises the key. If you use the wrong key it will start very briefly then cut out (with no spluttering) so I think that is probably another one to eliminate. I think even the shareware vag-com will be able to check the throttle position but I don't think it will be that since ithe engine is actually cutting out.

I would certainly check the relays especially if vag-com is having trouble communicating. Give them a tap/wiggle and see if that changes anything.
 

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Discussion Starter · #16 ·
Havent got any futher with this.

I bit the bullet and replaced the air-mass meter which made no difference what so ever.

This was the only fault code which appeared and I re-ran the vagcom and it still showed, I checked the wiring as much as I could and its all new.

Any more ideas????

I only have the basic program that was purchased off e-bay, would the fault code need to be erased from the ECU before it recognises the new air-meter is present???? as my software only reads fault codes and I dought it could talk to the ecu????

any help appreciated.
thanks.
 

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Discussion Starter · #17 ·
Your van does have an immobilizer. It recognises the key. If you use the wrong key it will start very briefly then cut out (with no spluttering) so I think that is probably another one to eliminate. I think even the shareware vag-com will be able to check the throttle position but I don't think it will be that since ithe engine is actually cutting out.

I would certainly check the relays especially if vag-com is having trouble communicating. Give them a tap/wiggle and see if that changes anything.
my software seems to be reading ok, I tried the 002 throttle test and that showed 0% to 100% when testing the throttle sensor.

where are the relays??, Ive found the fuse box with loads of blade fuses but no relays??
dont mean to sound dumb!
 

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As far as I know (I haven't had to change any on a T5) they are above the fuse box in the centre of the van. You might find them a bit awkward to get at. Check all the fuses with a meter while you are there. There is a second fuse box beside the battery and a voltage supply controller underneath the battery.

Obviously there are other things that could cause your problem like fuel supply etc and some things are impossible to check yourself (like the tandem pump that boosts the fuel pressure up for the pd injectors) but it's always good to eliminate simple the things first.

You hadn't only just filled up when the trouble started had you? :eek:
 

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Have you tried your spare key?
If not, do so. That will eliminate the transponder in the key if it don't work
 

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Discussion Starter · #20 ·
As far as I know (I haven't had to change any on a T5) they are above the fuse box in the centre of the van. You might find them a bit awkward to get at. Check all the fuses with a meter while you are there. There is a second fuse box beside the battery and a voltage supply controller underneath the battery.

Obviously there are other things that could cause your problem like fuel supply etc and some things are impossible to check yourself (like the tandem pump that boosts the fuel pressure up for the pd injectors) but it's always good to eliminate simple the things first.

You hadn't only just filled up when the trouble started had you? :eek:
:) ha no its had the same fuel in it for a couple of weeks.

Im taking it to a independent vw/audi dealer, ive had enough to be honest!
 
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