What does it mean?
SPECIAL NOTES: Code P0513 indicates an immobilizer related problem, and while modern automotive security/anti-theft systems have reached a high level of sophistication, the downside of this is the fact that sloppy maintenance/servicing procedures, unauthorized modifications to the electrical system of vehicles, and ill-considered attempts to “reset” the PCM by disconnecting the battery to “clear” unrelated trouble codes all have the potential to trigger the security system, which can cause the vehicle to be effectively immobilized.
In light of the above, non-professional mechanics are strongly urged to read the section in the application’s manual that deals with the security system before attempting to diagnose ANY security system related trouble codes. Failure to gain at least a basic understanding of the operation of the security system of the application being worked on could lead to misdiagnoses, many hours of wasted diagnostic time, and the unnecessary replacement of parts/components/control modules.
Worse, though, extensive, and often-fatal damage to the applications’ electrical system can also (and often does) occur as the direct result of unwarranted, ill considered, or sometimes-totally unnecessary diagnostic tests and procedures.
The fact is that most immobilizer related issues can often be resolved without having to take the vehicle apart, in a manner of speaking, and in many, if not most cases, the problem can very often be resolved simply by replacing the batteries in the key(s), reprogramming the key, or by reprogramming the PCM or other controller.
However, non-professional mechanics should note that generic code readers seldom have these capabilities, meaning that if suitable equipment is not available, the better option is to refer the vehicle for professional diagnosis and repair. Also, note that due to significant design differences between the security systems of the major car manufacturers, this guide cannot provide detailed diagnostic and repair information for code P0513 that will be valid for all applications under all conditions.
However, the generic diagnostic/repair information provided here should enable most non-professional mechanics to diagnose and repair code P0513 on most applications. END OF SPECIAL NOTES. OBD II fault code P0513 is a generic code that is most commonly defined as “Incorrect immobilizer key”, and is set when the anti-theft / security system on a vehicle does not recognize a key or key fob when attempts are made to either open/unlock, or start that vehicle.
While the specifics of anti-theft systems vary between applications, most systems share some common characteristics or operating principles, with the foremost being that all systems rely on the fact that several control modules need to interact successfully both with each other, and collectively with the key, before the fuel injection and ignition systems can be enabled.
In practice on most applications, the PCM (Powertrain Control Module), PIM (Powertrain Interface Module), and the BCM (Body Control Module) all need to recognize the key, in the sense that these modules can all “read”, or decode the heavily encrypted security code that is programmed into the key.
However, this initial interaction represents only the first “layer” of protection; a second “layer” requires that all affected modules interact further via the CAN (Controller Area Network) bus system to verify that all modules have recognised not only the key, but each other as well.
Put in another way, the security system needs to “know” that all affected modules have recognized the key, as well as each other, and that all affected modules “know” this, regardless of whether the key is used to unlock a door, or whether the key is inserted into the ignition lock. Only when all the affected modules have recognized the key as well as each other, will the PCM enable the fuel injection and ignition systems to allow the vehicle to be started. Thus, if an event, malfunctio