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Post by apache42 on Jun 15, 2023 19:23:13 GMT
I have an intermittent fault, and on the detail screen for the fault, ODBeleven (on iOS) says "Driving Cycle 255". Q#1: Is that a decaying timer, telling me that the car has to complete 255 drive cycles before the error will clear? I've driven the car 70 miles (and started it 4 times) since the error occurred, and it still says "Driving Cycle 255". Q#2: is this generic definition of a "Driving Cycle" repairpal.com/how-to-perform-a-basic-drive-cycle also applicable to mk7's? If so, it seems like it could take years of driving to go through 255 of those cycles! Screen captures of the ODBeleven fault screens are below:   Thanks in advance, -Ted |
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Post by dv52 (Australia) on Jun 15, 2023 23:51:59 GMT
Ted: Hi. I'm guessing that this is a "Yankee" car (because of the strange measurement unit "miles"  ) Drive cycle isn't a VW thing - it's a car industry thing that is defined in the OBD-11 Standard and it's an eight-stage course that results in an 8 x flag test report called "Readiness Codes" (the flags for the 8 x "Readiness Codes" do NOT map onto the eight x stage course). I've included details of the Drive cycle stages at the end of this reply (chosen in this case because it uses "Yankee" measurement units).
It's highly unlikely that the normal driving pattern that you experienced in this car by driving "70 miles" will NOT constitute even ONE Drive cycle. And as for your statement "it seems like it could take years of driving to go through 255 of those cycles" - I suggest that you replace "years" with the term "millennia"! This is because the definition of a Drive cycle by OBD-11 requires the car to undergo a very particular set of fixed driving stages, each of which must happen in a specific sequence (and the entire 8 x stages must be completed in 12 x minutes)!!
Drive Cycle =255 (the actual max number is 254) means that the car must undergo 255 x separate drive cycles (as defined in my chart) without the error code reappearing in any drive cycle before the error code will be automatically cleared by the module. 255 is the maximum number in decimal arithmetic that can fit into a single hexadecimal-pair - a hexadecimal pair is a measure of the capacity of the module's fault memory (Hexadecimal arithmetic is the numbering system used by the module - it's a base-16 counting system).
So what does my arcane description above mean in the real world? Well, Drive cycle =255 really means that there ain't much likelihood that this "intermittent" fault will be ever self-cleared by the module. Or said another way, Drive cycle =255 means that VW recommend that human intervention is needed to attend to this error - meaning actual human-based diagnostics and actual physical repair/replacement of faulty equipment!!
I can't see the value of the Priority number in your screenshot (it's hidden by "clear faults") - but I would guess that the number is low - meaning that this is a high priority fault in VW's view
My other observation from your screenshots is Frequency counter =1. The frequency counter measures the number of times that the same fault is re-registered in fault memory in a subsequent ignition cycle. So, if the error isn't cleared - it's a measure of the longevity of the fault over time (or, more accurately - across subsequent ignition cycles)
Don
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Post by apache42 on Jun 17, 2023 8:30:31 GMT
Don: that's a beautiful explanation, and I really appreciate the amount of time you spent typing up such an insightful and well-documented reply! It has thoroughly answered my "Driving Cycle 255" question, and you have certainly earned "the big piece of chicken" for writing up that detailed answer. (Southern reference to fried chicken dinner, and who gets the best piece of chicken from the platter). Your guess is correct, it's Priority 0. That's odd that it's not visible, as I actually posted 2 screen captures... (because I couldn't get all the info to fit in one screen)... and it's visible in the 2nd screen. I'll repost the second screen capture below. FYI, I originally wanted to post the ascii version of the OEBeleven fault info (as it has more details, such as VIN, engine type, model year, etc), but ran into a bizarre datacomm issue: - when I tell ODBeleven to email me the fault, it never arrives at my gmail address, and
- when I tell ODBeleven to text me the fault, the "ODBeleven_Log.txt" ascii file does indeed arrive on my iPhone Messages app. But... when I then try to forward that .txt file from my iPhone to gmail, it appears to work, but it never arrives. A few mins later, the Messages app says "Not delivered".
I subsequently discovered that on the apple support site, there's a long history of intermittent datacomm issues between iOS and gmail, with a bunch of random generic solutions (none of which worked). It's interesting that VW treats this as a high priority fault because it appears that it's really just a bookkeeping fault (an "EPA audit fault"), not a functional fault. The error "Radiator identification sensor, no communication", Fault Code U102F, means that an ID chip on the radiator (whose only purpose is apparently to tell the ECM that "an environmentally approved radiator is present") is no longer responding correctly. The radiator itself is perfectly fine. The ID chip is not available as a separate part from VW, so VW's solution is to replace the radiator and chip as one unit. This appears to cost $1,500, including labor. Someone discovered that this same radiator ID chip is available separately from Mercedes, but it requires about 2-3 hours to extract the radiator (apparently the bumper must be removed) and swap over the chips. Here's a good thread on this issue: www.golfmk6.com/forums/index.php?threads/u102f-cel-help.293196/page-4 , in case you're curious. So in my mind this is a very low priority (emissions compliance) error. There's actually a fairly long EPA warranty (8 years, 80,000 miles), but I am just slightly outside that window (at 9 years, 52,000 miles). So I'd need to pay for this silly repair myself. It hasn't actually triggered a CEL (Check Engine Light) on the dash, so I'm just going to manually clear it and "think happy thoughts", maybe it won't come back for a long time (as the fault count was only 1).  |
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Post by dv52 (Australia) on Jun 17, 2023 22:55:16 GMT
apache42 - thanks for the kind words (and for the allegorical chicken-piece)!!
As I said in my reply to your other post about Readiness Codes - I'm not familiar with "Yankee" versions of the ubiquitous Golf (in all it's various incarnations) - but I would have thought that you had a perfectly valid case for VW America to still recognize their warranty liability - notwithstanding hard time/travel limits imposed by VW.
The fact is that a Radiator identification sensor doesn't wear-out like other mechanical equipment in the car (such as a wheel-bearing, say). This sensor should last the life of the car and VW itself has acknowledged this fact by extending the formal warranty to 8 years, 80,000 miles!! Yes, this car has exceeded the warranty time limit by 12 months - but in this case, the traveled distance component of VW's warranty hasn't been exceeded.
From a warranty perspective and if VW deny the claim - this is the same as VW saying that it's reasonable for the sensor to fail if the car sits in a garage without traveling in the 9th year - which is an outrageous position for VW to take!
Again with the caveat that I'm an Antipodean making assertions about consumer rights in the land-of-the-free - I reckon that you have a very good basis for arguing that FULL warranty still applies and if not, that VW liability still persists at least in part (a big part)!!
Don
PS: the screenshots confirm that this fault is defined as being "intermittent". Of course anything is possible - but these type of errors often occur as a result of faulty/loose wiring connections. Have you checked the integrity of the pins at the plug (meaning - have you unplugged the sensor connector and actually eyeballed the quality of the mating pins)? Look for signs of water ingress, or evidence of detritus - maybe spray electrical-contact cleaner into the plug/socket
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Post by apache42 on Jun 20, 2023 19:00:10 GMT
dv42 - your suggestion is brilliant: I can't see the sensor, and am not quite sure where it is. The GTI engine compartment is much more tightly packed than the cars I'm used to working on (1987 Toyota, 1997 BMW). Fortunately I got a quick reply when I asked the author of the (only) video I was able to find on this topic: Unfortunately his answer was: "It's sandwiched between the condenser and radiator. So you can't unplug it without taking all of it apart sadly." You make excellent points about the warranty coverage, I totally agree.
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