The code that you caught when you checked the battery is interesting. In itself, it simply says that the voltage monitor module on your Jag's solenoid has registered 16 volts. It may also have shown up at the motor monitor module.
The reason it is interesting is that though it looks like it should be an easy find it is not. The reason it is not an easy find is that you have to locate the exact point of failure. You have to find out why the overvoltage code is being generated. That, in itself, is a chore because it mean you will have to eliminate, one by one, the each of the potential causes of the code.
That can take some doing because you will have to find whether the problem is in the high current side of the anti-lock braking system or whether it is simply a problem with the fuse. That means you have to check the 30 amp portion of the anti-lock system, the 20 amp portion of the anti-lock system and the "low" voltage section -- 10 volts -- of the anti-lock system. You must run each portion of the system from the source (battery input) through the output to the proper terminal on the ABS module. From the wiring information that I have found, the ABS circuit is made up of the four parts mentioned (three high-current lines and one "low" current line). There is a 30 amp circuit, 2 20-amp circuits and one 10-amp "low" current circuit. Each of these circuits have to be followed from test point to test point to determine where the failure is.
Notice, though, that when you find the general area where the fault is indicated, you will still have to trace the specific wire segment, which can be very time consuming. This also assumes that you have the proper equipment to do this. In this case, even a relatively inexpensive analog volt-ohhmeter will do, as you only need to find out where the voltage drops out on a wire to isolate the specific point.
The ABS system is not the only point of failure indicated by the B1317 code. It can also indicate an open circuit or short-circuited wire in one of the following points in the DSC HU/CM terminal, AK, AU or AT. This indicates a short or open between one of those three points and the battery.
On the other hand, it can also indicate a problem between DSC HU/CM terminal A or terminal B and the device's body ground.
The B1317 code can also indicate there is battery deterioration, as well as an alternator malfunction. It may also show that there is a problem with the charging system.
If a , then you must inspect the battery for deterioration. To check this, look at the battery terminals for heavy corrosion deposits. Also, look around the terminals for signs of leakage. Also, check along the battery case for leakage. If they equipment is available, check the specific gravity of thew battery. This indicates just how good the battery's electrolyte is. If you don't feel confident or you don't have the equipment available -- it is somewhat specialized -- then have your technician check it.
Finally, it may be that the charging system is at fault. First, you will have to check the output of the alternator itself. You can check to see if the alternator is putting out the right voltage by placing the probes of a voltmeter across the terminals of the alternator, after ensuring you have chosen the right voltage range. Simpler, though, is using the car's voltage gauge to see that your alternator is putting out the right voltage.
To do more, you will have to bring your car into a battery shop or to your dealer or an independent shop where they have the equipment to put a dynamic load on the charging system. They also have the diagnostic equipment needed to diagnose specific problems in the charging system.
As you can see, there's a lot more to looking for one specific cause when dealing with your car's electrical system. Because there are so many parts and circuits involved, it, almost instantly, becomes a time-consuming and painstaking job to check the electrical system correctly.
You can find tips on your car's battery and other information at:
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