Oil sensor yellow light
12-03-2011, 02:49 PM
#11
AudiWorld Super User
Not only that, but consider the pickle MB got itself into several years ago when it incorporated oil quality sensors into its cars but the sensors were calibrated for euro synthetic oils. MB authorized dino oil in NA cars and the sensors/algorithm failed to adequately predict oil life...result was a large number of sludged engines and MB buying new engines, etc.
12-03-2011, 02:51 PM
#12
AudiWorld Super User
Makes me wonder if it isn't capable of being enabled (enableable?) via Vag-Com...of course, subject to use of synthetic oils meeting euro standards...
12-03-2011, 03:46 PM
#13
AudiWorld Super User
Here is what your not seeing
No, I'm not mistaking anything. In the V8 cars this sensor reads oil quality, and that reading is used by the ECM to calculate the value to display in the service indicator.
C5 Bentley Service Manual, pg 17-6:
*emphasis is my own
The independent functions of oil level sensor and service interval counter you're describing is only applicable to the V6 cars. In the V8 cars the service indicator is not a simple dumb counter like in the V6's, in the V8's the oil level sensor works with the service indicator software in the computer to provide a more accurate calculations of the actual time before service is required.
For various reasons I have reset that service indicator to it's default of 12,000km several times in my car between oil changes, in each case the reading was with 500km of the previous reading after only a few kms of driving. The only possible explanation for that behaviour is that the computer can in fact also monitor oil quality in addition to temperature and level.
Perhaps the sensor is the same and the V8 ECM is simply able to read additional input off it which the V6 cars can't? Who knows, all I know is that the oil level sensor does in fact provide a third additional function for V8 powered C5 A6'S
C5 Bentley Service Manual, pg 17-6:
*emphasis is my own
The independent functions of oil level sensor and service interval counter you're describing is only applicable to the V6 cars. In the V8 cars the service indicator is not a simple dumb counter like in the V6's, in the V8's the oil level sensor works with the service indicator software in the computer to provide a more accurate calculations of the actual time before service is required.
For various reasons I have reset that service indicator to it's default of 12,000km several times in my car between oil changes, in each case the reading was with 500km of the previous reading after only a few kms of driving. The only possible explanation for that behaviour is that the computer can in fact also monitor oil quality in addition to temperature and level.
Perhaps the sensor is the same and the V8 ECM is simply able to read additional input off it which the V6 cars can't? Who knows, all I know is that the oil level sensor does in fact provide a third additional function for V8 powered C5 A6'S
I am referring to the ART,AWN and BBD electrical schematic diagram of the part with three wires and two functions, I am including this diagram for you to study, the level function is a switch "on/off" and the thermo section is an thermistor "temp/ohms". The key in both of these diagrams show three wires and one is a ground, not really trying to be snarky here but I am a twenty three year commercial refrigeration technician and have worked with many types of I/O controllers that would make the weak lick windows, you need to provide more substantial proof that this part samples oil without mentioning the computer algorithm or hysteresis dynamic lag between the input and output, we know that one.
Last edited by jcman; 12-03-2011 at 04:46 PM.
12-03-2011, 05:14 PM
#14
AudiWorld Member
jcman, you can choose to believe whatever you want... however I choose to believe the service manual, the Audi service bulletin posted above and the evidence of my own experience with the flexible service indicator in my 2000 4.2L A6. All of it serves to confirm that the existence of this function and use of the sensor.
I'm also not trying to by snarky here, but if Audi's own documentation on the function of this sensor isn't enough "proof" for you then there's really not much point in continuing the debate.
I'm also not trying to by snarky here, but if Audi's own documentation on the function of this sensor isn't enough "proof" for you then there's really not much point in continuing the debate.
12-03-2011, 05:17 PM
#15
AudiWorld Member
It was enabled by default in the non-US market cars, I have one of them. My guess is that, like the above bulletin stated, it was never enabled on US cars which explains jcman's belief that it doesn't exist. Product liability seems a likely given MB's experiences.
Last edited by mithrilG60; 12-03-2011 at 05:24 PM.
12-03-2011, 06:42 PM
#16
AudiWorld Super User
My beliefs are based on facts, not gray areas.
jcman, you can choose to believe whatever you want... however I choose to believe the service manual, the Audi service bulletin posted above and the evidence of my own experience with the flexible service indicator in my 2000 4.2L A6. All of it serves to confirm that the existence of this function and use of the sensor.
I'm also not trying to by snarky here, but if Audi's own documentation on the function of this sensor isn't enough "proof" for you then there's really not much point in continuing the debate.
I'm also not trying to by snarky here, but if Audi's own documentation on the function of this sensor isn't enough "proof" for you then there's really not much point in continuing the debate.
12-04-2011, 08:12 AM
#17
AudiWorld Super User
Interesting theory, but not true...
Having owned the car since new, maybe I can connect a few dots.
Geographies/politics: On the Euro side, oil changes are traditionally long. They accept 20K km+ and well over a year. Nothing like our old stereotype of 3 moths or 3k miles. Further, the Green movement was perceived as very politically strong in Germany and elsewhere in N. Europe, Audi/VW's home markets. Frequent oil changes are seen as wasteful and polluting there by at least some. Also, notice how on the pre -update C5's (<2002) they buried the exhaust, as did the other German co's in that era. Another nod to (faux) eco. think. Audi threw in the towel by 2002 when the "mine's bigger" display became the norm for HP marketing. On the U.S. side, I recall Audi/VW type quotes also basically saying U.S. customers wouldn't buy very extended interval logic.
Economics: European's don't typically get free service for a period of years as Audi offered for all C5's. They are more incented to be frugal early. Meanwhile, since on the US side Audi paid for it in the C5 generation, changes were stretched out over time--better fuel delivery and oil quality plays some roll, but not all of it. Still left on fixed intervals, but loosened up.
The Mercedes theory is interesting, but BMW has had a bunch of motor issues too--the "Mount Vesuvius" M3, problems with V8 aluminum blocks in general, very spotty reliability on the current Mini turbo (S) generation (turbo's, broken pistons, chain tensioner etc.) Yet, BMW has been using long variable intervals for some time, and shows no sign of backing down. Coming back to the Audi motor where we are debating this (the 4.2), Audi had been using it for several years already in the D2 A8. The underlying block concept, 5V heads, etc. were sprinkled around Audi/VW motors. From my 35 year experience w/ them, Audi's have many issues, but typically not in the block, whether the older cast iron ones or the newer aluminum ones.
Geographies/politics: On the Euro side, oil changes are traditionally long. They accept 20K km+ and well over a year. Nothing like our old stereotype of 3 moths or 3k miles. Further, the Green movement was perceived as very politically strong in Germany and elsewhere in N. Europe, Audi/VW's home markets. Frequent oil changes are seen as wasteful and polluting there by at least some. Also, notice how on the pre -update C5's (<2002) they buried the exhaust, as did the other German co's in that era. Another nod to (faux) eco. think. Audi threw in the towel by 2002 when the "mine's bigger" display became the norm for HP marketing. On the U.S. side, I recall Audi/VW type quotes also basically saying U.S. customers wouldn't buy very extended interval logic.
Economics: European's don't typically get free service for a period of years as Audi offered for all C5's. They are more incented to be frugal early. Meanwhile, since on the US side Audi paid for it in the C5 generation, changes were stretched out over time--better fuel delivery and oil quality plays some roll, but not all of it. Still left on fixed intervals, but loosened up.
The Mercedes theory is interesting, but BMW has had a bunch of motor issues too--the "Mount Vesuvius" M3, problems with V8 aluminum blocks in general, very spotty reliability on the current Mini turbo (S) generation (turbo's, broken pistons, chain tensioner etc.) Yet, BMW has been using long variable intervals for some time, and shows no sign of backing down. Coming back to the Audi motor where we are debating this (the 4.2), Audi had been using it for several years already in the D2 A8. The underlying block concept, 5V heads, etc. were sprinkled around Audi/VW motors. From my 35 year experience w/ them, Audi's have many issues, but typically not in the block, whether the older cast iron ones or the newer aluminum ones.
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