# 2005 Honda Civic ECU **URL:** \ **Category:** Maintenance/Repairs\ **Tags:** civic-cpe, honda\ **Created:** [October 22, 2022, 2:02pm UTC](https://community.cartalk.com/t/2005-honda-civic-ecu/187027 "2022-10-22T14:02:46Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![kmj4458](https://avatars.discourse-cdn.com/v4/letter/k/9fc29f/32.png) [@kmj4458](https://community.cartalk.com/u/kmj4458)\ **Post date:** [October 22, 2022, 2:02pm UTC](https://community.cartalk.com/t/2005-honda-civic-ecu/187027/1 "2022-10-22T14:02:46Z")
I have been told I need a new ECU. Neither the repair shop nor I have been able to find the exact replacement (outside of going to the dealer)… Does anyone have any recommendation for a company that provides these? ---
**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\ **Post date:** [October 22, 2022, 2:10pm UTC](https://community.cartalk.com/t/2005-honda-civic-ecu/187027/2 "2022-10-22T14:10:35Z")
See if one can be attained from a local auto recycler. Tester ---
**Author:** ![VOLVO-V70](https://avatars.discourse-cdn.com/v4/letter/v/8e8cbc/32.png) [@VOLVO-V70](https://community.cartalk.com/u/VOLVO-V70)\ **Post date:** [October 22, 2022, 2:23pm UTC](https://community.cartalk.com/t/2005-honda-civic-ecu/187027/3 "2022-10-22T14:23:00Z")
Now I don’t know if they actually have one but a web search shows several places that sell ECU . Even the Autozone web site has a remanufactured ECU listed . I suspect that the shop just does not want to mess with this repair . ---
**Author:** ![jtsanders](https://avatars.discourse-cdn.com/v4/letter/j/c2a13f/32.png) [@jtsanders](https://community.cartalk.com/u/jtsanders)\ **Post date:** [October 22, 2022, 2:32pm UTC](https://community.cartalk.com/t/2005-honda-civic-ecu/187027/4 "2022-10-22T14:32:17Z")
Have you tried these? I did a web search and these are a sample of what is available. > **[2003-2005 Honda Civic ECU Electronic Control Unit](https://www.greentecauto.com/hybrid-battery/accessories/inverters/honda-inverters/honda-ecu-modules/honda-civic-2003-2005-ecu)** > > Electronic Control Unit ECU for Honda Civic Hybrid. 24 months warranty > **[05 2005 Honda Civic Electronic Control Unit - Engine Electrical - A1 Cardone...](https://www.partsgeek.com/catalog/2005/honda/civic/engine_electrical/electronic_control_unit.html)** > > Buy a 2005 Honda Civic Electronic Control Unit at discount prices. Choose top quality brands A1 Cardone. > **[Civic Engine Control Computers - Best Engine Control Computer for Honda Civic...](https://www.autozone.com/engine-management/engine-control-computer/honda/civic)** > > Order Honda Civic Engine Control Computer online today. Free Same Day Store Pickup. Check out free battery charging and engine diagnostic testing while you are in store. > **[2005 HONDA CIVIC 1.7L L4 Engine Control Module (ECM Computer) | RockAuto](https://www.rockauto.com/en/catalog/honda,2005,civic,1.7l+l4,1430771,electrical,engine+control+module+(ecm+computer),2896)** > > RockAuto ships auto parts and body parts from over 300 manufacturers to customers' doors worldwide, all at warehouse prices. Easy to use parts catalog. ---
**Author:** ![bcohen2010](https://avatars.discourse-cdn.com/v4/letter/b/779978/32.png) [@bcohen2010](https://community.cartalk.com/u/bcohen2010)\ **Post date:** [October 22, 2022, 3:10pm UTC](https://community.cartalk.com/t/2005-honda-civic-ecu/187027/5 "2022-10-22T15:10:40Z")
I would go to the dealer, have them diagnose the problem, and if necessary replace the PCM (which is what I assume is meant by ECU). The 2005 Civic has a security system, and a used PCM from a junkyard is unlikely to work without reprogramming, and the dealer is unlikely to be willing/able to reprogram a used PCM. **Usually, the software tools available at the dealer level can only record a VIN and other necessary parameters into a new/blank PCM, and cannot erase/reprogram this information to a used one which was already programmed.** Without proper programming, the security system will not allow your engine to start. ---
**Author:** ![texases](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/texases/32/862_2.png) [@texases](https://community.cartalk.com/u/texases)\ **Post date:** [October 22, 2022, 6:00pm UTC](https://community.cartalk.com/t/2005-honda-civic-ecu/187027/6 "2022-10-22T18:00:07Z")
How do you know that’s the problem, OP? ---
**Author:** ![ok4450](https://avatars.discourse-cdn.com/v4/letter/o/e9bcb4/32.png) [@ok4450](https://community.cartalk.com/u/ok4450)\ **Post date:** [October 22, 2022, 6:40pm UTC](https://community.cartalk.com/t/2005-honda-civic-ecu/187027/7 "2022-10-22T18:40:53Z")
I tend to go along with texases as ECU failure is not that common and “blame the computer” is; often by shops. What are the symptoms or codes if any? From a vague memory I seem to recall there are 3 or 4 fuses involved in the ECU operation so I would hope the possibility of an open fuse has at least been checked. ---
**Author:** ![George\_San\_Jose1](https://avatars.discourse-cdn.com/v4/letter/g/e5b9ba/32.png) [@George\_San\_Jose1](https://community.cartalk.com/u/George_San_Jose1)\ **Post date:** [October 22, 2022, 9:16pm UTC](https://community.cartalk.com/t/2005-honda-civic-ecu/187027/8 "2022-10-22T21:16:51Z")
> [@kmj4458](#): > > I need a new ECU. Neither the repair shop nor I have been able to find the exact replacement (outside of going to the dealer) I doubt even a Honda dealership will stock a brand new ECU exact replacement part for your 17 year old car. You’ll likely have to use a re-furbished used unit. The advice above to ask a dealership shop to handle this problem for you soup-to-nuts seems sound however, as the job will likely involve a complex reprogramming job, possibly requiring electronic tools only a dealership will have. If you decide to use a non-dealership shop, be sure to ask how they plan to deal with the security system, transmission controls and sensors, and any state requirements involving things like preserving the current mileage on the odometer, etc. For more info on ECU replacement, suggest to surf over to the Summit Racing website. Have you entertained the idea your current ECU might could be removed and bench-repaired? If that was possible, the computer software configuration problem would already be solved. ---
**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\ **Post date:** [October 22, 2022, 9:41pm UTC](https://community.cartalk.com/t/2005-honda-civic-ecu/187027/9 "2022-10-22T21:41:36Z")
> [@bcohen2010](#): > > and a used PCM from a junkyard is unlikely to work without reprogramming, [![](https://global.discourse-cdn.com/cartalk/original/3X/7/0/70782003769864ded7f62d9c387ecc6830639f6b.jpeg "Honda Civic - ECU Swap") ](https://www.youtube.com/watch?v=jWsaOHnjYLM) Tester ---
**Author:** ![kmj4458](https://avatars.discourse-cdn.com/v4/letter/k/9fc29f/32.png) [@kmj4458](https://community.cartalk.com/u/kmj4458)\ **Post date:** [October 23, 2022, 9:47pm UTC](https://community.cartalk.com/t/2005-honda-civic-ecu/187027/10 "2022-10-23T21:47:27Z")
Thank you all. I would be happy to get a refurbished unit, but have been led to believe by both the repair shop and the dealer that the 11 digit code assigned to the ECU needs to be an exact match. When I look online I cannot find an ECU that matches. Also, it has been confirmed that the manufacturer does not have anymore. If anyone knows whether I can somehow used a mismatched unit I would be interested. As to whether or not it is an ECU problem, if codes should show up then I’ll ask the shop for those. I am just going by what they have told me so far, and I do trust them. ---
**Author:** ![George\_San\_Jose1](https://avatars.discourse-cdn.com/v4/letter/g/e5b9ba/32.png) [@George\_San\_Jose1](https://community.cartalk.com/u/George_San_Jose1)\ **Post date:** [October 23, 2022, 9:55pm UTC](https://community.cartalk.com/t/2005-honda-civic-ecu/187027/11 "2022-10-23T21:55:54Z")
> [@kmj4458](#): > > If anyone knows whether I can somehow used a mismatched unit I would be interested Is your car required to pass a state emissions test from time to time, like every 2 years? If so, that might further complicate the matter. ---
**Author:** ![Nevada\_545](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/nevada_545/32/41232_2.png) [@Nevada\_545](https://community.cartalk.com/u/Nevada_545)\ **Post date:** [October 23, 2022, 10:05pm UTC](https://community.cartalk.com/t/2005-honda-civic-ecu/187027/12 "2022-10-23T22:05:20Z")
A remanufactured PCM should have the immobilizer data already cleared and ready for the installer to register the vehicle’s security data to new PCM. ---
**Author:** ![George\_San\_Jose1](https://avatars.discourse-cdn.com/v4/letter/g/e5b9ba/32.png) [@George\_San\_Jose1](https://community.cartalk.com/u/George_San_Jose1)\ **Post date:** [October 23, 2022, 10:17pm UTC](https://community.cartalk.com/t/2005-honda-civic-ecu/187027/13 "2022-10-23T22:17:35Z")
> [@kmj4458](#): > > As to whether or not it is an ECU problem, If not certain, probably a good idea to investigate this further before presuming you need a replacement ECU. ECU failure is not a very common problem by the reports we get here. Ask your shop for the reason(s) they think the ECU needs to be replaced. One valid reason could be the battery was installed backward or a jump-start was wired up backward. Did anything like that occur? ---
**Author:** ![kmj4458](https://avatars.discourse-cdn.com/v4/letter/k/9fc29f/32.png) [@kmj4458](https://community.cartalk.com/u/kmj4458)\ **Post date:** [October 23, 2022, 10:41pm UTC](https://community.cartalk.com/t/2005-honda-civic-ecu/187027/14 "2022-10-23T22:41:58Z")
No emissions testing required. There has been a recent battery jump attempt on old battery and new battery replacement but both were after car started having no start problem. ---
**Author:** ![kmj4458](https://avatars.discourse-cdn.com/v4/letter/k/9fc29f/32.png) [@kmj4458](https://community.cartalk.com/u/kmj4458)\ **Post date:** [October 23, 2022, 10:43pm UTC](https://community.cartalk.com/t/2005-honda-civic-ecu/187027/15 "2022-10-23T22:43:08Z")
Battery jump and replacement were performed correctly. ---
**Author:** ![kmj4458](https://avatars.discourse-cdn.com/v4/letter/k/9fc29f/32.png) [@kmj4458](https://community.cartalk.com/u/kmj4458)\ **Post date:** [October 23, 2022, 10:45pm UTC](https://community.cartalk.com/t/2005-honda-civic-ecu/187027/16 "2022-10-23T22:45:43Z")
Nevada…does that mean I don’t need an exact number match. For example, mine is labeled 37820-PMP-130 ---
**Author:** ![George\_San\_Jose1](https://avatars.discourse-cdn.com/v4/letter/g/e5b9ba/32.png) [@George\_San\_Jose1](https://community.cartalk.com/u/George_San_Jose1)\ **Post date:** [October 23, 2022, 10:46pm UTC](https://community.cartalk.com/t/2005-honda-civic-ecu/187027/17 "2022-10-23T22:46:25Z")
> [@kmj4458](#): > > after car started having no start problem Maybe you should go back to square one here. What symptom are your trying to solve? If no-start is the only problem, is the the kind of no start where it cranks ok – that rrr rrrr rrr sound – but won’t catch and run? Or it doesn’t crank w/key in start? ---
**Author:** ![kmj4458](https://avatars.discourse-cdn.com/v4/letter/k/9fc29f/32.png) [@kmj4458](https://community.cartalk.com/u/kmj4458)\ **Post date:** [October 23, 2022, 10:54pm UTC](https://community.cartalk.com/t/2005-honda-civic-ecu/187027/18 "2022-10-23T22:54:10Z")
Both nothing and cranking with no start intermittently. Also, intermittent rpm problems, killing idle problems. Thanks ---
**Author:** ![kmj4458](https://avatars.discourse-cdn.com/v4/letter/k/9fc29f/32.png) [@kmj4458](https://community.cartalk.com/u/kmj4458)\ **Post date:** [October 23, 2022, 10:57pm UTC](https://community.cartalk.com/t/2005-honda-civic-ecu/187027/19 "2022-10-23T22:57:32Z")
Otherwise, the car runs fine. ---
**Author:** ![texases](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/texases/32/862_2.png) [@texases](https://community.cartalk.com/u/texases)\ **Post date:** [October 23, 2022, 11:36pm UTC](https://community.cartalk.com/t/2005-honda-civic-ecu/187027/20 "2022-10-23T23:36:26Z")
It sounds like you have the seventh generation, made from 2001-2005. You might do some searches on Civic forums to see if others have had similar problems with that generation. There may be some other causes that are easier to test for, since replacing the ECM is difficult and expensive. [Next page](https://community.cartalk.com/t/2005-honda-civic-ecu/187027.md?page=2)