Madasafish

Yes...And Japanese codes tend to differ from others..

It may need a clean. Carb Cleaner should work. Best way is to remove and clean.. probably all gummed up. Be careful of any sensors - you should treat them with great care...

I think it is the quality of the socket holding the bulb and the wiring. If the earth contact corrodes or the bulb contacts get damp, bulbs will fail. Constant vibration does not help. I noticed when upgrading headlamp bulbs when I bought my Yaris (and my Jazz more recently) that both had electric grease liberally covering the terminals . I don't know if other makers do that..Makes contacts far less susceptible to corrosion.

As a matter of principle I would check the camshaft sensor.. And the crankshaft one as well... and the wiring to them.

I would suggest trying the battery connections first: both on the battery and the earth to body. A corroded or loose connection will break when load applied.. Why first? Cos it is free if you diy.. (I am a mean Scot)

Our Yaris D4D has been owned by us for 13 years. No bulbs have failed in that time..

Wider tyres are not good for loose snow-- higher rolling resistance

Broken rear spring (rust).. most likely . Ours had last year. Or failed rear rubber bushes Or failed shock absorber..

Petrol Yarises gave mpg on the trip. Diesel Yarises did not. Ours does not (2003) I assume the RAV you have is similar to the Yaris.(in technology terms) I understand later diesels may (probably do) have mpg displays.

On our 2003 D4D, I use Toyota's own antifreeze and any fully synthetic 5w-30 oil with the correct spec. (Halfords when on offer at £15 for 4 liters often)

Ours is similar. A treatment with Redex fuel treatment (for diesels) helps a little.

When the engine is stone cold from an overnight stop, all sensors will tell the ECU a very rich mixture is need to start the engine. And that continues until the sensors detect the engine is warming up. If you start, drive say 10 meters and stop, the rich mixture meets cold metal .. and condensation occurs on the plugs, piston and cylinder head. Now in that mix will be some fumes from unexpelled exhaust gases .. which are mainly .. water. So you get a mix of petrol and water swilling around. Try to restart and engine rotates again and some of it lands on the plugs. Water and electricity do not mix.. Used to a major problem with early fuel injection. Start car, drive out of garage. Stop engine . Wash car. Car does not restart... Rover 820 i was bad: I used to drive out and leave running for 10 mis whilst I washed it.. Whereas my 1967 Lotus Elan with twinchoke Weber carbs never gave a problem..(well not with cold starting ) Not usually an issue with diesels.No plugs.

Err Japanese built models 1999 to 2004 had a conventional torque convertor gearbox...

I have the same issue when driving son's yaris occasionally. Driver error..

I would suggest the throttle body is dirty. Try cleaning it first. How many miles?