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Discussion Starter · #1 ·
What is actually
wrong with this part? Will this have an effect on my fuel consumption? Which
lambda probe does this point to and where is it located? As its intermittent
does this mean there is a loose wire or something, and help gladly appreciated.

Address 01: Engine
Controller: 022 906 032 E
Component: MOTRONIC ME7.1 G V007
Coding: 00132
Shop #: WSC 00639
1 Fault Found:
17516 - Oxygen (Lambda) Sensor Heating: B2 S1: Performance too Low
P1108 - 35-10 - - - Intermittent
Readiness: 0000 0000
 

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Discussion Starter · #3 ·
do you know which one one as there are 2 of them? do you know if this will affect my fuel comsumption?
 

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Most lambda probes are fitted with a heater element to get them up to temp and working quicker (usually 4 wires , 1 grey ,1 black and 2 white) , this code would indicate that the heater circuit for the pre-cat sensor is intermittantly faulty.This could be within the sensor it`s self or the wiring to the sensor , the two white wires in a 4 wire sensor are usually the feed / return to the heater element.
 

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quite possibly yes .Once the engine is warm the management system goes into "closed loop" operation which means it takes a fuel mixture reading from the sensor to adjust the mixture to the correct value via the injectors , if the sensor`s heater element is faulty it could cause the sensor to react more slowly even when warm and this can cause excessive fuel consumption and in the worst case a failure of the cat convertor.
 

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Discussion Starter · #10 ·
Nooooooooooooooooooooooooo!!! [cry] So I guess having 2 going is even
worse,[:O]

Address 01: Engine

Controller: 022 906 032 E

Component: MOTRONIC ME7.1 G V007

Coding: 00132

Shop #: WSC 00639

2 Faults Found:

17516 - Oxygen (Lambda) Sensor Heating: B2 S1: Performance too Low

P1108 -
35-10 - - - Intermittent

17511 - Oxygen (Lambda) Sensor Heating: B1 S1: Performance too Low

P1103 -
35-10 - - - Intermittent

Readiness: 0000 0000

Do you know where the 2 pre-cat probes connect to? Is it underneath the car
under that plastic cover next to the cat? If you know where I mean.
 

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I think so yes , it`s usually an underneath job to check them out especially on a V6 `cos there`s not much room in the engine bay to access anything from the top.
 

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Discussion Starter · #12 ·
WOW!!! It sounds and looks like a night mare, there's
exhaust and heat shielding every where, not to mention the minute amount or
space available, has anyone actually changed these themselves on a 4 motion before or have
any diy guides?[:D]
 

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Discussion Starter · #14 ·
Interesting read Mr Bear, So I presume I dont have the wide band
sensor as I dont think the V6 is a lean burn engine, but then again
accoring to elsawin the 2 pre-cat sensors have 6 wires, so maybe it
does? The link you sent me also refers to the wide band sensor as
universal or UEGO sensor which I dont think these are
http://www.lambdasensor.com/main/muniversal.htm. as they are cheaper
with less wires (probably just means generic?). Anyway I presume the
heater element is just to get the sensor up to temp quicker when the
engine is cold, or am I wrong and the heater is actually needed to keep
the sensor at optimum running temp?........

I would have thought that
the exhaust gases keep the sensor at the right temp?, or are exhaust
gases on there own not able to do this.? If they are then it does`nt
take long for my V6 to warm up maybe 5 mins max driving at constant
30mph and the temp gauge reads at 12 o clock. Am I wasting fuel in this 5 min warm up time if the heater part is faulty. Whats you view on this?
by the way no engine check light is illuminated on the dash, I get
these errors through vag com. Cant say ive noticed any bad fuel
consumption or engine irregualities, maybe ive just got used to it.
Looks like somethings going on thou as I have 2 sensors with the same
fault now.

I`ll have to check the connections 1st before I buy
new lamdba sensors, as I`ve seen on other posts on here that people
have had the same errors codes changed the lambda sensors and the same
error code is still there (http://uk-mkivs.net/forums/thread/123215.aspx). To be fair the cars on 59K miles now and i dont think any of the sensors have been changed from new, so they may well be on there way out[:p]

Anyone know the bosch lambda part numbers for a V6 AUE engine? I have this 0258007075 at £105 each for direct fit sensors, can anyone else do any better
 

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Interesting read Mr Bear, So I presume I dont have the wide band
sensor as I dont think the V6 is a lean burn engine, but then again
accoring to elsawin the 2 pre-cat sensors have 6 wires, so maybe it
does? The link you sent me also refers to the wide band sensor as
universal or UEGO sensor which I dont think these are
http://www.lambdasensor.com/main/muniversal.htm. as they are cheaper
with less wires (probably just means generic?).
Now you will know my true ignorance - I simply do not know. The article I linked in the previous message was on a Subaru and I thought it explained the operation of the sensors pretty well. I was not inferring that it directly applied to your car or your particular sensor but rather that it explained more clearly the reason that heaters are used to get the sensor up to operating temperature sooner. The sooner the sensors are operational, the sooner the control goes closed loop and can begin adjusting the fuel mixture. As the article said, while cold, the ECU depends on fixed parameters to run the engine and it does not run efficiently. My 06 Audi A4 comsumes way more fuel until things get up to temp and part of that is due to the O2 sensors not being at temp (forcing the engine to be in open loop control).

Anyway I presume the
heater element is just to get the sensor up to temp quicker when the
engine is cold, or am I wrong and the heater is actually needed to keep
the sensor at optimum running temp?........
Yes, that is my understanding also.

I would have thought that
the exhaust gases keep the sensor at the right temp?, or are exhaust
gases on there own not able to do this.?
I'm not certain about that and will keep looking for more answers. I don't know if the exhaust gases by themselves can keep the sensor up around the 1400F mark on their own. I would think they could but then thinking for me is a dangerous thing!

If they are then it does`nt
take long for my V6 to warm up maybe 5 mins max driving at constant
30mph and the temp gauge reads at 12 o clock. Am I wasting fuel in this 5 min warm up time if the heater part is faulty. Whats you view on this?
by the way no engine check light is illuminated on the dash, I get
these errors through vag com. Cant say ive noticed any bad fuel
consumption or engine irregualities, maybe ive just got used to it.
Looks like somethings going on thou as I have 2 sensors with the same
fault now.
If the sensors are not functioning, I would expect the car to throw the check engine light because one of their functions is to allow the ECU to "guestimate" the efficiency of the CAT and if they are not functioning, the check engine light should light to indicate you are stinking up the world! But again, see my statement above about what I really know and how dangerous it is for me to think!

I`ll have to check the connections 1st before I buy
new lamdba sensors, as I`ve seen on other posts on here that people
have had the same errors codes changed the lambda sensors and the same
error code is still there (http://uk-mkivs.net/forums/thread/123215.aspx). To be fair the cars on 59K miles now and i dont think any of the sensors have been changed from new, so they may well be on there way out[:p]
I was not making any recomendations about whether or not to replace the sensors. I was trying to help you get a clear idea of how these things work so that you might be able to better diagnose what's going on in your car. I am not a car tech. I'm a geek that rides a desk and tries to help run a business. I am a EE by training so when things go wrong with my car, I try to learn about them so I can understand what the guys are talking about when they go to fix it. I had a discussion with one of our guys a couple months ago about how these sensors work. Been around closed loop electronics a long time but didn't quite understand the physics of the O2 sensors. If I find anything specific on VAG car sensors, I'll let you know.
 

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Discussion Starter · #16 ·
Thanks for your help and time, Mr Bear[;)] Keep me posted if you find anything more specific to VAG cars, I`ll when I get time will check my heater circuits and see whats what.
 

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Discussion Starter · #17 ·
Right had a look at the connection box under the car for the Lambda probes, unplugged them all and sprayed some contact lubricant on the pins, reseated them a couple of times and put it all back together......Still get the below fault, the 2nd sensor fault I had went away when I cleared the codes with vagcom...strange[:S]

Address 01: Engine
Controller: 022 906 032 E
Component: MOTRONIC ME7.1 G V007
Coding: 00132
Shop #: WSC 00639
1 Fault Found:
17516 - Oxygen (Lambda) Sensor Heating: B2 S1: Performance too Low
P1108 - 35-10 - - - Intermittent
Readiness: 0000 0000

I also noticed this on the connector side of the Lambda probe,(the connectors under the car which i cleaned that is) It had a cover on it which I removed to reveal what to me looks like some kind of resistor, but Im not too sure if thats what it is..can any one enlighten me as to what it actually is. Its only on the 2 pre-cat(6 wire) connectors and not the post-cat(4 wire) ones.

 

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I have looked at this, it is a low value thick film resistor which has been laser trimmed to a particular resistance.

It does not connect to any of the other elements of the lambda probe, I believe it is used to deliver an initial calibration value to the ECU.
 

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Discussion Starter · #19 ·
Hmmmm...... interesting, have you got any more info on this BigAl. If i got a new replacement lambda probe will i get the entire loom with this connector and all the protective casing that surrounds the actual wires?
 

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Assuming that you buy the correct part from VW, yes you will get the
short loom and the connector with the resistor already wired to the
probe.

Once you have removed the old probe and refitted the new one, it takes seconds to plug the new one in.

If
you do this yourself, you need to reset the ECU after
fitting the new sensor so that the it recognises it and recalibrates.
 
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