# 240sx 1995 ECU Questions **URL:** https://forums.speedlife.net/t/240sx-1995-ecu-questions/95345 **Category:** SON240sx Automotive **Created:** [April 27, 2006, 3:25pm UTC](https://forums.speedlife.net/t/240sx-1995-ecu-questions/95345 "2006-04-27T15:25:18Z") **Posts on this page:** 10 **Page:** 1
### Author: ![redpotatoes](https://avatars.discourse-cdn.com/v4/letter/r/ecae2f/32.png) [@redpotatoes](https://forums.speedlife.net/u/redpotatoes) #### Post date: [April 27, 2006, 3:25pm UTC](https://forums.speedlife.net/t/240sx-1995-ecu-questions/95345/1 "2006-04-27T15:25:18Z")
I got myself a 1995 240sx spare ECU to work on, my question is the following, how can I know if this ECU is ODB1 or ODB2, I opened up the ECU, what should I look for to get my information ? If there any noticiable differences in between obd1 and odb2 ECU board for 1995 ? ---
### Author: ![Theo23](https://avatars.discourse-cdn.com/v4/letter/t/43a26b/32.png) [@Theo23](https://forums.speedlife.net/u/Theo23) #### Post date: [April 27, 2006, 3:58pm UTC](https://forums.speedlife.net/t/240sx-1995-ecu-questions/95345/2 "2006-04-27T15:58:21Z")
'95 is only OBDI ---
### Author: ![redpotatoes](https://avatars.discourse-cdn.com/v4/letter/r/ecae2f/32.png) [@redpotatoes](https://forums.speedlife.net/u/redpotatoes) #### Post date: [April 27, 2006, 4:14pm UTC](https://forums.speedlife.net/t/240sx-1995-ecu-questions/95345/3 "2006-04-27T16:14:21Z")
No it’s not, I have a 95 Odb2. 2 oxygen sensor before and after the catalityc converter. Anyine has a clue for what to lock for on the ECU board ? ---
### Author: ![Theo23](https://avatars.discourse-cdn.com/v4/letter/t/43a26b/32.png) [@Theo23](https://forums.speedlife.net/u/Theo23) #### Post date: [April 27, 2006, 5:21pm UTC](https://forums.speedlife.net/t/240sx-1995-ecu-questions/95345/4 "2006-04-27T17:21:21Z")
obdI has 2 02 sensors aswell, I had 2 95’s myself. obdII was used beginning with the '97 models. take some pics of it and post them, I have an obdII computer right here so I can compare Theo ---
### Author: ![\_RSTuning.ca](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/_rstuning.ca/32/6098_2.png) [@\_RSTuning.ca](https://forums.speedlife.net/u/_RSTuning.ca) #### Post date: [April 27, 2006, 6:15pm UTC](https://forums.speedlife.net/t/240sx-1995-ecu-questions/95345/5 "2006-04-27T18:15:47Z")
i currently have a 1995 240sx and it has 2 o2 sensors but it is still obd1, because im running the bikirom board which does not work on obd2 systems. ---
### Author: ![redpotatoes](https://avatars.discourse-cdn.com/v4/letter/r/ecae2f/32.png) [@redpotatoes](https://forums.speedlife.net/u/redpotatoes) #### Post date: [April 27, 2006, 6:36pm UTC](https://forums.speedlife.net/t/240sx-1995-ecu-questions/95345/6 "2006-04-27T18:36:37Z")
Thats what I am trying to find out, I will also install the bikirom. From what I read, earlier model of 1995 were obd1 and late were odb2. I am not sure how to verify what model I have, here is the pictures: ![http://memimage.cardomain.net/member_images/9/web/765000-765999/765280_113_full.jpg](http://memimage.cardomain.net/member_images/9/web/765000-765999/765280_113_full.jpg) ![http://memimage.cardomain.net/member_images/9/web/765000-765999/765280_114_full.jpg](http://memimage.cardomain.net/member_images/9/web/765000-765999/765280_114_full.jpg) ![http://memimage.cardomain.net/member_images/9/web/765000-765999/765280_115_full.jpg](http://memimage.cardomain.net/member_images/9/web/765000-765999/765280_115_full.jpg) ---
### Author: ![\_RSTuning.ca](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/_rstuning.ca/32/6098_2.png) [@\_RSTuning.ca](https://forums.speedlife.net/u/_RSTuning.ca) #### Post date: [April 27, 2006, 7:03pm UTC](https://forums.speedlife.net/t/240sx-1995-ecu-questions/95345/7 "2006-04-27T19:03:47Z")
i think the only way to tell is to us to verify serial numbers and see how close they are, asside from that its pretty impossible. i know JWT has a spead sheet of ecu codes to what year but i remember it not being so helpful. i say just install the board and see if it work if not then reinstall in a 94 ecu. i think it will work though. looks identical to mine. ---
### Author: ![redpotatoes](https://avatars.discourse-cdn.com/v4/letter/r/ecae2f/32.png) [@redpotatoes](https://forums.speedlife.net/u/redpotatoes) #### Post date: [April 27, 2006, 7:14pm UTC](https://forums.speedlife.net/t/240sx-1995-ecu-questions/95345/8 "2006-04-27T19:14:25Z")
I has a look at JWT and all the 240sx 1995 identify are ODB2. My code listed. I will have a look at the one in my car. I am just wondering where are the obd1 for 1995. How can you tell that your ECU is odb1 and not odb2 ? ---
### Author: ![greybrother](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/greybrother/32/5551_2.png) [@greybrother](https://forums.speedlife.net/u/greybrother) #### Post date: [April 27, 2006, 9:39pm UTC](https://forums.speedlife.net/t/240sx-1995-ecu-questions/95345/9 "2006-04-27T21:39:49Z")
Pretty sure the 95’s were OBDI. There are 2 O2 sensors in both OBDI and OBDII . The difference is that the first one, near the manifold is 1-wire (unheated) on OBDI, and 2-wire (heated) for OBDII. There are other differences in the fuel vapour systems too between '95 and '96 too. ---
### Author: ![redpotatoes](https://avatars.discourse-cdn.com/v4/letter/r/ecae2f/32.png) [@redpotatoes](https://forums.speedlife.net/u/redpotatoes) #### Post date: [April 27, 2006, 10:07pm UTC](https://forums.speedlife.net/t/240sx-1995-ecu-questions/95345/10 "2006-04-27T22:07:19Z")
So it’s only possible to know if a ECU is odb1 or obd2 if it’s with the car ? I will have a look at the one I have installed in my car right.