Rennaissance and Porsche Fault Code Diagnostics
From time to time, your Porsche may tell you that something is wrong. Hopefully this communication won't leave you stranded on the side of the road! Generally speaking there are often warnings of a failure before a breakdown occurs. One way modern cars warn of failures is by displaying a warning lamp. We're going to talk a bit about these but first we're going to discuss the difference between Diagnosis and Repair. |
Diagnosis and Repair Defined
In automotive language, the term Diagnosis can be defined by the following statement: the necessary testing phase in the repair process in which a technician uses tools and equipment to troubleshoot a symptom with the intent to develop an appropriate repair strategy; disassembly may often be required to complete this process. Once our Diagnosis is complete, we estimate repair costs using said repair strategy. The term Repair describes the execution of the aforementioned repair strategy. The goals, methods and tools used during diagnosis often differ from those used during a repair. These two procedures are completely separate from one another in most cases. For example, there may be a fee for the diagnosis(finding the cause) of a 'Check Engine Lamp' fault and a separate fee for it's repair(fixing it).
Labor Overlap
Sometimes diagnosis and repair operations do coincide and there is what's known as 'Overlap', where disassembly to confirm a diagnosis will allow us begin the repair where the diagnosis left off. In cases like this, we will certainly be fair and transfer any savings directly to our client.
In automotive language, the term Diagnosis can be defined by the following statement: the necessary testing phase in the repair process in which a technician uses tools and equipment to troubleshoot a symptom with the intent to develop an appropriate repair strategy; disassembly may often be required to complete this process. Once our Diagnosis is complete, we estimate repair costs using said repair strategy. The term Repair describes the execution of the aforementioned repair strategy. The goals, methods and tools used during diagnosis often differ from those used during a repair. These two procedures are completely separate from one another in most cases. For example, there may be a fee for the diagnosis(finding the cause) of a 'Check Engine Lamp' fault and a separate fee for it's repair(fixing it).
Labor Overlap
Sometimes diagnosis and repair operations do coincide and there is what's known as 'Overlap', where disassembly to confirm a diagnosis will allow us begin the repair where the diagnosis left off. In cases like this, we will certainly be fair and transfer any savings directly to our client.
Warning Lights and Associated Faults
Porsche uses warning lights to let the driver know that something is wrong. Each and every system on the vehicle is managed by a Electronic Control Unit(ECU). ECU's constantly monitor themselves and their system's activity. When something goes wrong, a Fault or error code is stored in it's Fault Memory.
Porsche uses warning lights to let the driver know that something is wrong. Each and every system on the vehicle is managed by a Electronic Control Unit(ECU). ECU's constantly monitor themselves and their system's activity. When something goes wrong, a Fault or error code is stored in it's Fault Memory.
Fault Code Diagnosis Once we have access to the vehicle, we connect our diagnostic computer and initiate communication. With the PIWIS, we are granted access to all vehicle control units(ECU's) and their respective Fault Memories. When the Check Engine Lamp is illuminated, this is an indication that there are Faults in the engine management system which can sometimes be traced to Faults in other ECU's. A Fault is a defined code that the ECU gives to an stored error. We use this code as a map to know where to begin searching for the cause of the Fault. The screen shot to the left was taken from a Boxster Fault Memory. Note the Fault Code at the bottom highlighted in blue. |
Fault Codes in Other ECU's Reading fault codes in various ECU's is daily activity in the workshop. We routinely connect the PIWIS to read faults even if the Check Engine Light is not displayed. Many ECU's listed on the vehicle do not display warning messages in the instrument cluster when there are fault codes stored. The PIWIS 2 screenshot to the right shows a portion of a control module list. If faults are stored in any of the vehicle's control modules, the diagnostic computer will tell us. |
What We Do with Fault Codes
Once we know the fault code(s), the testing phase of the diagnosis procedure begins. Our technician proceeds to troubleshoot the suspected system using a test plan published by Porsche(if available). If a test plan is not available, the tech pulls from knowledge and experience of the system to troubleshoot the faults. This phase can be difficult and time-consuming, however, sometimes we're able to find the cause using simple tests that take little time.
Diagnosis without Fault Codes
What do we do when a symptom is not traceable with fault codes? What if the vehicle is an older model and doesn't have an on-board diagnostic system? Answer: we do it the old fashioned way. Experience, knowledge of how the system works and tools are used to test the system until enough data is collected to form a repair strategy.