I have the PO201 error code which appears randomly every 30Km to 50 Km. The issue sounds possible as the car ran 2000Km with a damaged spark in cylinder 1 before repair.

However, they are no circuits plugged on injectors. They are connected directly to a set of wire. The ʟᴘɢ engine speed varies between 600 to 900 rpm every second and little less when on gasoline.
There is a small box with many pluggable electronics components near the left headlamps, but if it’s inside I’ve no idea each thing belongs to: From what I read (if I’m not wrong) this seems to be an amplifier for giving enough current to actually command the injector from the weak signal coming from the ᴇᴄᴜ.

  • So what are you asking?
    – Solar Mike
    Apr 14, 2019 at 11:32
  • @SolarMike the injectors were changed during previous repairs, so where is the part between the ecu and the first injector which needs to be replaced? Apr 14, 2019 at 12:00

1 Answer 1


The injector circuit is simply said the whole system that controls the injector, including the injector itself, quoting from https://www.obd-codes.com/p0201:

P0201 means that the PCM detected a fault in the injector or the wiring to the injector.

It means the injector system anywhere from the ECU to the injector is faulty. It could be the wiring. It could be the amplifier. It could actually be the ECU. It could also be the injector.

I would say if the cylinder 1 had issues in the past life of the vehicle, it's more likely that the component near the issues (i.e. the injector) is faulty than the component far away from the injectors (let's say the wiring, amplifier or ECU) is faulty.

You could try switching the injector from cylinder 1 to some other cylinder, so that it uses the wiring and position of another cylinder. Then you'll see whether the problem code changes to the other cylinder.

  • I have no idea on how to remove injectors. Apr 14, 2019 at 12:03
  • @user2284570 Well, that's one option out. Me neither... But if the injectors were changed 2000km, ago, perhaps you could take the car to the shop that did the previous repair? I mean, surely there should be some sort of warranty on their work. It seems to me that one of the replaced injectors could be faulty.
    – juhist
    Apr 14, 2019 at 12:13
  • 2000km was how long the damaged spark was there, whatever damaged spark really means, before repair - not how long since injectors changed which could have just been done...
    – Solar Mike
    Apr 14, 2019 at 12:21
  • I went for an engine change but the shop wasn't able to do it in full. They drove almost 400km in tests burning half of a filled gas tank without being able to fix all problems because of lack of knowledge. Toyota isn t enjoyed at the idea of warranting their repairs based on the previous work of someone else. Apr 14, 2019 at 12:45
  • @user2284570 I’m having trouble trying to work out what you mean from what you say... “how does Toyota enjoy warranty” ??
    – Solar Mike
    Apr 14, 2019 at 14:32

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