I need to replace the engine control unit, ECU, of my Honda Civic 2000, my car doesn't have an immobilizer, it starts with a basic metal key, so, do I need to program the used ECU replacement?

  • If it starts, why do you think you need to replace the ecu? – Solar Mike May 13 '19 at 4:33
  • When it turned on before the ECU was damaged. – Alan May 13 '19 at 4:52
  • Thank you for your answer. – Alan May 13 '19 at 5:01
  • If the answer helps, please accept it using the tick top left so that the system "closes" the question and it is not returned to the top of the pile under review. – Solar Mike May 13 '19 at 5:04
  • Any chance of damaging something if it start without programming and use it like that? Does the ECU needs to be installed for programming? – Alan May 13 '19 at 5:22

As it is clear that the old ecu is damaged then if it does not start with the new ecu, then it definitely needs programming.

If it does start, then it may need programming for best performance etc


Unless its actually a 1999 then it should be equipped with a immobilizer. 2000+ Honda Civics all use transponders so if its actually a 2000 and one is starting with an all metal key then 1 of 2 things have happened.

  1. The ecu was modified and the immobilizer was tuned out or emulated inside the ecu.
  2. Someone has taped a key or transponder under the dash inside the antenna.

A proper ecu replacement will need to have the immobilizer tuned out again or either the ecu will need matching with the immobilizer system AND key with properly coded transponder inside. I usually prefer HDS (honda diagnostics software) or Autel's 908 but many tools can do these older Honda immo systems.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.