the picture below is a device that came with my 1993 toyota carina e

  • Looks like a car alarm control unit to me. – max Sep 11 '19 at 10:11
  • That exact same picture is on this website as an ECU for a Renault Laguna - pieces-okaz.com/en/computer-engine-ecu/… – HandyHowie Sep 11 '19 at 11:31
  • So that is not the OP's own photo. – Weather Vane Sep 11 '19 at 12:30
  • yes but i have the same thing in my 1993 carina e and i want it name and functions because am having some electrical issues. thank you – Diligent Love Sep 11 '19 at 15:17
  • 1
    @DiligentLove Trying to be gentle here - you can't really sub in a pic of something that looks-kinda-sorta-like-it instead of giving us actual details. If you have the exact same thing then I'd be saying I'm not surprised you have issues - it's the ECU from a Renault Laguna so it probably wouldn't work very well in a Toyota Carina. But I don't think that's what you have. How about you wind it back a few steps and tell us what problems you are having, what symptoms your car is exhibiting and we can try work from there? – motosubatsu Sep 11 '19 at 16:28

It's an engine control module, and it's not the problem.

AKA "computer". However, "computers" usally get blamed for any electrical problem, first because old-guard mechanics hate the things and long for the simple old days, and second because their functionality is fairly opaque and hard to analyze/test, and third, because resetting a computer often clears the problem (at least temporarily). Replacing a computer is a rather expensive way to reset a computer.

The engine computer relies on a variety of sensors and actuators to manage the engine. For instance, it has a coolant temperature sensor that tells it how hot the engine is, and an oxygen sensor to sense whether the right amount of fuel is being injected. It has an EGR actuator that recycles exhaust gases when necessary to improve smog/fuel economy. It might have as many as two dozen sensors or actuators. Those fail all the time. And fortuantely, they're cheap.

I have yet to see a computer that is actually dead. However, I have seen many, many faulty sensors or actuators, and occasionally, a damaged wiring harness.

In particular, a "Check Engine" light is the computer saying "I am working properly, but one of my sensors is borked or telling me the engine is borked". This is the point where idiots replace the computer :)

Mind you, this is only likely to bear on engine-related problems, or possibly speedometer. If something is amiss in the body wiring, e.g. Funky radio, power windows not working, etc. -- for that, you need to look to a "Body control module" (if there even is one in a '93, not that likely) which is a separate computer that manages comfort and convenience devices in the body... Or plain old wiring issues like stuck switches, frayed wires etc.

  • Boss thanks for your explanation i really appreciate but my car already has ECU and this one too. But my car uses petrol and LPG gas and i don't know if the ECU in the picture works with the LPG – Diligent Love Sep 12 '19 at 7:50
  • @DiligentLove This is information you should have put in your question. Is there any more information that you are keeping from us. For all we know this device could have been in a cardboard box in the car trunk. – HandyHowie Sep 12 '19 at 9:30
  • Then it must be the Body Control Module I also mentioned. Again, probably not the problem. – Harper - Reinstate Monica Sep 12 '19 at 15:45

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