clarkes
New member
Could this be our own Robert Prince?
http://www.timesonline.co.uk/tol/driving/car_clinic/article6912766.ece
http://www.timesonline.co.uk/tol/driving/car_clinic/article6912766.ece
If this forum can't help, perhaps The Times can?
- Thread starter clarkes
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berty987
New member
Sounds like the car should be taken to a Bosch diagnostics center rather than porsche main agent. Porsche technicians will surely know how to diagnose faults thrown up on the PWIS but probably dont know the intimate details of the bosch fuel injection and engine management system. As I found with my PASM dampers , sometimes it pays to go back to the original supplier rather than rely on the local knowledge of your porsche main agent. The water cooled engines on the 997/ 987 also have a secondary air pump which assists the emissions when the car is cold , with this level of complexity and additional hardware , you really need someone that understands the principles of operation rather than just how to read out fault codes. Bosch diagnostics wil also be cheaper than main agent prices and they may have the ability to return the ECU to Bosch for testing.
Shouldn't Porsche provide this level of support though and if not outsource it to the likes of Bosch? In my experience the PIWIS is a limited diagnostic tool and leads customers into the realm of if it's not a listed fault then there can not be one - that being the case the system is coded for every possible problem in advance which in my experience, e.g. 997 alarm system, is not realistic.
Diagnostic technology should be better in this day and age (IMO) and lack of could be a symptom of building the product and thinking about the support afterwards (a classic engineering problem). Are any other manufacturers any better? An engineer suggested to me that BMW and Renault are a generation ahead of Porsche in this respect. Would be interested to hear any opinions on the Italian front.
Diagnostic technology should be better in this day and age (IMO) and lack of could be a symptom of building the product and thinking about the support afterwards (a classic engineering problem). Are any other manufacturers any better? An engineer suggested to me that BMW and Renault are a generation ahead of Porsche in this respect. Would be interested to hear any opinions on the Italian front.
berty987
New member
Agree that it's disappointing Porsche don't often go the extra mile , though it's understandable since most of the car is manufactured by other companies and simply bolted together by Porsche. Porsche are unlikely to have , need , or justify the expense of purchasing the test gear to check every component or sub assembly. I would further suggest , in most cases it's easier for the local OPC to make few phone calls to porsche Ag technical and replace parts , rather than go outside of the Porsche network , direct to the OEM supplier. As far as I'm aware there are quite strict guidelines on what the local OPC is authorised to do and they must always follow procedure. The other reason for procedure being in most cases it's cheaper and quicker to replace a part than to remove and diagnose. Removed parts will often be returned to Porsche in Germany where I suspect the factory may take up any re occuring issues with the original supplier.
Regarding the case in question, I suspect Porsche have no previous experience of this fault and do not consider it worth dispatching a technical specialist to investigate , particularly as the car is outside of warranty and appears to be a "one off" with this fault. Therefore, approaching a Bosch specialist may be the most cost effective and quickest route to resolving the issue for the individual concerned. Many of the complex parts on these cars are simply throw ayay items or black boxes to the technicians , Porsche simply don't have the money or time to train them to be experts in every part of every car.
Regarding diagnostics, I think in most cases the diagnostics are actually supplied by the manufacturer of the component, ie the PWIS unit is actually a re badged Bosch diagnostics tool. In the case of Renault and BMW , their track record for defective components would suggest its more about their experience and frequency of diagnosing faults rather than the quality of the diagnostic equipment. The PWIS is already a complex piece of equipment, adding in extra diagnositcis would only serve to extend the training required to use it and the cost of purchasing the device. In most cases the manufacturer will provide self check systems on components that flag out major faults indicating a replacement is required. The main issue is making these new systems and hardware more reliable whilst allowing them to be more complex , the trouble comes when it all has to made to a price , a short timeline and be cost effective.
Regarding the case in question, I suspect Porsche have no previous experience of this fault and do not consider it worth dispatching a technical specialist to investigate , particularly as the car is outside of warranty and appears to be a "one off" with this fault. Therefore, approaching a Bosch specialist may be the most cost effective and quickest route to resolving the issue for the individual concerned. Many of the complex parts on these cars are simply throw ayay items or black boxes to the technicians , Porsche simply don't have the money or time to train them to be experts in every part of every car.
Regarding diagnostics, I think in most cases the diagnostics are actually supplied by the manufacturer of the component, ie the PWIS unit is actually a re badged Bosch diagnostics tool. In the case of Renault and BMW , their track record for defective components would suggest its more about their experience and frequency of diagnosing faults rather than the quality of the diagnostic equipment. The PWIS is already a complex piece of equipment, adding in extra diagnositcis would only serve to extend the training required to use it and the cost of purchasing the device. In most cases the manufacturer will provide self check systems on components that flag out major faults indicating a replacement is required. The main issue is making these new systems and hardware more reliable whilst allowing them to be more complex , the trouble comes when it all has to made to a price , a short timeline and be cost effective.
Plugging in Bosch systems (sourced via the likes of VW/Skoda it would appear in the case of the alarm system) means cost savings and brings down time to market, but with the added complexity that modules talk to each other, e.g. alarm interior sensor talks to module B which talks to Module A which talks to siren, lack of a support tool which supports tracing/discovery of intermittent faults seems to be a problem which Porsche have not addressed outside of I assume their design facility. This means pattern matching to solve problems and if you are the first to have the problem you are at the mercy of guesswork (which part to replace?) => time/annoyance, if not cost.
As each generation of vehicle naturally becomes more electronically intelligent this could be more of an issue than I am making it out to be now...
As each generation of vehicle naturally becomes more electronically intelligent this could be more of an issue than I am making it out to be now...
berty987
New member
Virtually all of the electronic systems fitted to Porsche vehicles are proprietry systems already available and commercially in use on other makes and models. The economies of scale do not permit Porsche to go the bespoke route for sub assemblies and components , therefore they use systems already available and tailor them into their cars. One exception is the Uk alarm system siren which is made specifically to meet thatcham approval here in the UK. The company that makes the siren and also made the tilt sensor for the 986/996 is a small concern called Hamilton Palmer. Understanably they do not have the resources to make a fully integrated "smart" siren that can talk to the rest of the CAN network, so in essence this is a dumb device and cannot be fault diagnosed other than by testing its output.
Though smart diagnositics can save time , if it were to be applied to all electronic modules the costs of development would easilly double , making the cost of the component prohibitive. Many companies simply do not have the resources or feel the need to spend time , up front during development considering potential failure modes and detection. Often the detection system itself requires additional hardware or sensors adding further to complexity. Put simply the rate at which cars advance , there is often a new design being developed as the current design goes into production. Most manufacturers try to avoid the need for diagnostics by ensuring the quality of manufacture and components ensures an acceptable service life.
Intermittent problems are the most difficult to diagnose , since the problem cannot be traced conclusively unless data loggers are introduced , checking various points around the system/ loop. Often components behave in different ways , depending on the status of the system at the time, therefore you need to gather a lot of information about the state of the system and ensure its all logged on the same time base. Even with this information you then need to know how the system is supposed to respond , ie understand the software/ process flow diagram. With electronic systems you often need additional data other than simple voltages , currents or resistances , waveforms time bases or reference voltages can all become critical. If you look at the size of commercial equipment capable of monitoring multiple inputs for this information , it soon becomes clear why it cannot be integrated into the existing vehicle control system. As a result , only a simple fault logging and diagnostic loop can be integrated. I'm sure over time , as processor power and memory becomes cheaper , smaller and more available , the logging and diagnostrics will develop as the reliance on electronics increases.
It's almost impossible to predict every failure mode for every electronic component, so fault diagnostics should be seen as an aid rather than the only way of diagnosing a fault. As I mentioned before, Porsche technicians do not have the depth of knowledge to fix problems that are not already known about (on their knowledge base) or may require in depth knowledge of the system or component. Any issue is usually progressed upwards back to Porsche Ag , to technical specialists and people connected to the suppliers. As with any large company this is a torturous route and takes much time. If you have no leverage with Porsche (ie the car is out of warranty) then I suggest its better to short circuit the red tape and speak directly with the OEM supplier or their agent.
When I retro fitted the battery backed siren and tilt sensor to my own car , I found that the Porsche knowledge of the system was very limited. Only by talking with the original supplier and researching the way in which the CAN systems worked , was I able to identify how the system could be retro fitted. Since Porsche had no previous experience of doing this task , they had no way of helping , and were not prepared to investigate as the demand was limited.
Unfortunately if you find yourself with an unusual or difficult to diagnose problem you have two options , either accept that it may take a number of attempts to be repaired at your local OPC by a practice of substitution. Alternatively take the car to a specialist for that particular element where they may have more knowledge or better diagnostics/ knowledge base. This was the route I ended up taking with my rattling rear suspension , the damper was taken back to Bilstein and tested and found faulty as Porsche had no diagnostics other than to look at or shake the damper neither of which was a particularly scientific or conclusive test.
Though smart diagnositics can save time , if it were to be applied to all electronic modules the costs of development would easilly double , making the cost of the component prohibitive. Many companies simply do not have the resources or feel the need to spend time , up front during development considering potential failure modes and detection. Often the detection system itself requires additional hardware or sensors adding further to complexity. Put simply the rate at which cars advance , there is often a new design being developed as the current design goes into production. Most manufacturers try to avoid the need for diagnostics by ensuring the quality of manufacture and components ensures an acceptable service life.
Intermittent problems are the most difficult to diagnose , since the problem cannot be traced conclusively unless data loggers are introduced , checking various points around the system/ loop. Often components behave in different ways , depending on the status of the system at the time, therefore you need to gather a lot of information about the state of the system and ensure its all logged on the same time base. Even with this information you then need to know how the system is supposed to respond , ie understand the software/ process flow diagram. With electronic systems you often need additional data other than simple voltages , currents or resistances , waveforms time bases or reference voltages can all become critical. If you look at the size of commercial equipment capable of monitoring multiple inputs for this information , it soon becomes clear why it cannot be integrated into the existing vehicle control system. As a result , only a simple fault logging and diagnostic loop can be integrated. I'm sure over time , as processor power and memory becomes cheaper , smaller and more available , the logging and diagnostrics will develop as the reliance on electronics increases.
It's almost impossible to predict every failure mode for every electronic component, so fault diagnostics should be seen as an aid rather than the only way of diagnosing a fault. As I mentioned before, Porsche technicians do not have the depth of knowledge to fix problems that are not already known about (on their knowledge base) or may require in depth knowledge of the system or component. Any issue is usually progressed upwards back to Porsche Ag , to technical specialists and people connected to the suppliers. As with any large company this is a torturous route and takes much time. If you have no leverage with Porsche (ie the car is out of warranty) then I suggest its better to short circuit the red tape and speak directly with the OEM supplier or their agent.
When I retro fitted the battery backed siren and tilt sensor to my own car , I found that the Porsche knowledge of the system was very limited. Only by talking with the original supplier and researching the way in which the CAN systems worked , was I able to identify how the system could be retro fitted. Since Porsche had no previous experience of doing this task , they had no way of helping , and were not prepared to investigate as the demand was limited.
Unfortunately if you find yourself with an unusual or difficult to diagnose problem you have two options , either accept that it may take a number of attempts to be repaired at your local OPC by a practice of substitution. Alternatively take the car to a specialist for that particular element where they may have more knowledge or better diagnostics/ knowledge base. This was the route I ended up taking with my rattling rear suspension , the damper was taken back to Bilstein and tested and found faulty as Porsche had no diagnostics other than to look at or shake the damper neither of which was a particularly scientific or conclusive test.
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