Bench supply volt meter readout malfunction

The alternator isn't a possible cause as it is basically there to charge the battery when the engine is running. The resistance reading you have is low so shouldn't be an issue.
The codes mean :-

P0201 = Injector 1 - circuit malfunction.
P0202 = Injector 2 - circuit malfunction.
P2146 = Fuel Injector Group "A" Supply Voltage Circuit/Open.

This could be an issue with the actual injectors. Injectors are commonly numbered to match the cylinder they feed fuel to so you have a possible problem with the injectors on cylinders 1 and 2. If they need replacing I would seriously recommend getting a good diesel mechanic to do it. Some engines use a pressurised fuel injection system running at a PSI powerful enough to blast fingers off.

Battery voltage is high, suspect alternator over charging and affecting the monitor. Connect an external volt meter across the battery and start engine 15volts or above will cause problems. If left charging high, it can shorten the life of the battery and damage electronics of the vehicle, things like abnormal amount of bulbs blowing. All electrical equipment is made to operate at around 13 volts with a percentage tolerance, constant running at a higher voltage will cause damage.

You will need a volt/ohm meter to accurately diagnose this unit as well as be familiar with it's use and have a basic grasp of electrical theory. To suggest you troubleshoot a device that can kill you should you make 1 mistake would be irresponsible.
Your description is pretty vague, if it does "nothing" that suggests it may not be getting power, check the breaker and re set it, even if it looks ok.The breaker may not be marked correctly or marked at all,
this is fairly common.
Look under the unit to see if it is hard wired or plugged in, check the outlet as well if it has one, wiring can be loose or burnt typically at a connection with a wire nut.
The draft motor if not running needs to tested for the correct voltage supplied and if it has this test for any amp draw. If you get voltage but no amp draw its bad, if you get an amp draw but it still wont work its physically worn or electrically shorted to itself internally..
The burners will not be allowed to come on until the draft is proven. As you can see there are many things that can cause a malfunction, at what point in a sequence of operation this occurs is critical to us ascertaining what it may be.
Get back with an observation of the units function and sequence of operation , we may be able to assist you better.

I'm going to assume your meter is accurate and you have verified the 18.4 reading.
Something has to be bypassing the regulator to make the alternator charge at full power. The regulator breaks the circuit dozens of times per minute to maintain 14 volts. Does the alternator charge with the regulator unplugged ?

KDL- Bravia blink codes (Australian):
2 times-Main power supply voltage error (12V, etc)
3 times-Malfunction of 3.3V line
4 times-Malfunction of 5V line
(Voltage Supply to FE, etc)
5 times-Malfunction of power supply for screen
6 times-Malfunction of inverter or overcurrent, etc
7 times-Abnormal temperature inside unit
8 times-Audio circuit error (amplifier, etc.)
9 times-Fan malfunction
10 times- Digital FE circuit error
11 times-Malfunction of Trident IC or around IC
12 times-BH board error
13 times -Malfunction of balancer
If this is correct the 5 blinks is the power supply having problems, I would much rather change the PS than replace the screen. Also if screen is determine bad, look for class action lawsuit on Sony for defective screen, i am told they know all about this.

You cannot test the power supply on the bench just by connecting it to the mains power. You need to know which pins on the connector to activate the power supply and you need to connect a load to the power leads.
The best way to test the power supply is to leave the power unit connected to the computer power up the computer and test a spare 4 wire power connector with a multi-meter. Leave the other power leads connected to the various drivers.
If computer's power LED should light up then test the voltages.
The Red and black wire should read 5 volts.
The Yellow and black wire should read 12 volts.
If the power LED does not light up, check the mains lead in another appliance to see if the mains lead is OK.
If the mains lead is OK then most likely the switch mode power supply has died.

If this charger is one that plugs into the radio then you will have to take a volt meter and check the voltage on the plug. It should be close or slightly higher in voltage than the label on the power supply.
It most likely be that the transformer or the contacts in the plug are bad.
You could try and turn on the radio with the battery on and see if the radio comes on.

What kind of inverter is it and what kind of meter are you using to check the voltage with? If the inverter puts out modified sine wave, you have to use a true rms volt meter to accurately check the voltage with. A non rms volt meter will show a low reading.

this is a sensor problem possibly the air flow meter ,take vehicle to dealers for a proper diagnostics

The power supply failed. It could also be the lights malfunctioning but is very unlikely.
The 5 volts DC line is not providing a proper voltage to the circuitry. 12 volts seems to be working since you have audio.