Engine management light problem..

Cle0dy · Post by **Cle0dy** » Sun Sep 25, 2011 7:00 pm

First post here, so be gentle..

Bought my 03 9N back in July there, however my EML has been coming on since then, and after 3 different diagnostics (from different garages using 'Snap On' fault code readers) my problem seems to be an 'intermittent' fault with the o2 management. (Lambda sensor)

However, after replacing the sensor myself, and wiping the fault, its suddenly came back on again!

Has anyone else encountered this problem?

cheers!

benmkiv · Post by **benmkiv** » Sun Sep 25, 2011 7:17 pm

Sure that you have replaced the right one?

Cle0dy · Post by **Cle0dy** » Sun Sep 25, 2011 7:18 pm

absolutely. just at the front under the engine cover amirite?

benmkiv · Post by **benmkiv** » Sun Sep 25, 2011 7:31 pm

I think that there is two lambda sensors?? Not hundred percent sure, if not could be the plug or the wiring which can be very common too

Cle0dy · Post by **Cle0dy** » Sun Sep 25, 2011 7:37 pm

I'll need to look into this a bit more, as i only thought there was one

these sensors are a bit of a pain in the arse tbh, i just hope that if there is a problem (even though its 'intermitent) it doesnt interfere with my fuel consumption!

Not really sure about taking it to a local auto electrician either, cause the last one my mum went to robbed me her £120 over the space of two jobs trying to fix a 'grinding' automatic lock on her old car.

benmkiv · Post by **benmkiv** » Sun Sep 25, 2011 7:41 pm

It is highly likely that it will affect your fuel consumption. Do you have a fault code at all?

Cle0dy · Post by **Cle0dy** » Sun Sep 25, 2011 7:44 pm

nah, i didnt take note of the fault code the fella registered.
all i know is, its intermitent, and its the o2 sensor.. its doing my nut in!

Cle0dy · Post by **Cle0dy** » Sun Sep 25, 2011 7:48 pm

next time i get it cleared, i'll write down the code

Cle0dy · Post by **Cle0dy** » Tue Jan 24, 2012 11:29 pm

Right, bit of an update on this problem..

After replacing the top o2 sensor in bank 1, i got the car fully serviced today and got the mechanic to fit a new sensor in the lower bank 2 under the car.

After taking it a test run, he said the engine management light came back on and the fault code reader showed it was now bank 1 that was showing the problem and cleared the fault seeing as its a new sensor.

Basically the light came back on after an hour of driving away from the garage. Car still chugs at low RPM's, which is sometimes dangerous when emerging at roundabouts as i get say 10mph speed with the foot down then suddenly it kicks in.

Known this mechanic for years so i know im not being mugged off, however this is becoming a fu**ing joke now and i cant afford to keep spending money on o2 sensors and labour.
Like i said, its had a full service today so im assuming its nothing to do with spark plugs or filters etc.

Anyone have a clue about this or encountered this problem and can give me some advice?

RUM4MO · Post by **RUM4MO** » Wed Jan 25, 2012 8:23 am

Right, first off, what is your engine type/code?

Next, just to correct you a wee bit, its not "bank1" and "bank2" its sensor s1 or sensor s2 - bank1 is the cylinder bank1 - so all Polos only have one bank normally, bank2 is the second bank of a VEE configuration engine.

You really need to give out more facts about that reported fault code, really just to see what the engine's ECU is seeing, its not just getting reported as " s1 faulty".

So you did change the correct one the first time round, ie the one fitted near the exhaust manifold, that is a regulating sensor, the second one is just a measuring sensor to warn of emissions problems, so the first one could affect the drivability of the car.

One thing though, did you buy a proper VAG product, you should have as they are made by NGK (probably brand NTK like all NGK's "other" products)?

For £40 you can buy a VAG code reader from Gendan ( www.gendan.co.uk ) it will let you read engine ABS, SRS codes and clear them any time - but write them down first!

Cle0dy · Post by **Cle0dy** » Wed Jan 25, 2012 3:13 pm

Update on those codes

16514

17524

Cle0dy · Post by **Cle0dy** » Wed Jan 25, 2012 3:16 pm

RUM4MO wrote:Right, first off, what is your engine type/code?

Next, just to correct you a wee bit, its not "bank1" and "bank2" its sensor s1 or sensor s2 - bank1 is the cylinder bank1 - so all Polos only have one bank normally, bank2 is the second bank of a VEE configuration engine.

You really need to give out more facts about that reported fault code, really just to see what the engine's ECU is seeing, its not just getting reported as " s1 faulty".

So you did change the correct one the first time round, ie the one fitted near the exhaust manifold, that is a regulating sensor, the second one is just a measuring sensor to warn of emissions problems, so the first one could affect the drivability of the car.

One thing though, did you buy a proper VAG product, you should have as they are made by NGK (probably brand NTK like all NGK's "other" products)?

For £40 you can buy a VAG code reader from Gendan ( http://www.gendan.co.uk ) it will let you read engine ABS, SRS codes and clear them any time - but write them down first!

Nah, it was a cheaper one off ebay due to lack of funds with being unemployed and stuff. Still brand new and stuff though but i'll pick up an NGK one from my local motor factors. Might also look into getting one of those VAG code readers, the sound proper handy to have as well.

RUM4MO · Post by **RUM4MO** » Wed Jan 25, 2012 8:39 pm

I did check around online to see if I could buy a proper one, same as VAG supply, cheaper than at dealer, but by the time I added in P&P it was just the same price to get absolutely the correct one from dealer - of course with the option to return it if they had supplied the wrong one (by comparing connector + cable length etc).

Its not right, but, it seems that lots of these "equivalent" parts supplied by a third party are sometimes only good for fitting before "punting on" the repaired car - not nice!

RUM4MO · Post by **RUM4MO** » Wed Jan 25, 2012 10:40 pm

[quote="Cle0dy"]Update on those codes

16514 Lambda sensor S1 (nearest engine) malfunction in circuit

17524 Lambda sensor S1 (nearest engine) open circuit

Still looks like that probe is faulty - that is as long as its heater supply is okay.(I can't expand on that as I don't know where the supply comes from or fuse)

Thing is, these sensors are ignored when the engine is cold, so the fault light will only come on when the engine is ready to "use" the sensors.

It was the heater circuit that was shorting out on the one that I had to change and the code was slightly different because of that - same out come though - S1 u/s.

Cle0dy · Post by **Cle0dy** » Wed Jan 25, 2012 11:23 pm

Im pretty sure i noticed the word 'heater' on the mechanics diagnostic tool in relation to the second code actually! He was using a snap on one, and i had a nosey and wrote down the codes. Given that both sensors have been replaced, do tou think its possible that the heater circuit could actually be causing the problem? And if so, how do i replace and fix it??

(really appreciate all this help btw mate!

)

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