Honda Civic / Del Sol (1992 - 2000) EG/EH/EJ/EK/EM1 Discussion

code 21

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Old Jun 8, 2019 | 01:39 PM
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Default code 21

why is my non-vtec b18b1 running code 21 when its not a vtec>>>since i already know that code 21 is for the vtec solenoid valve
Old Jun 8, 2019 | 03:08 PM
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Default Re: code 21

Wrong ECU for engine.
Old Jun 9, 2019 | 02:26 PM
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Default Re: code 21

i bought the 1993 honda civic with the b18b1 swap [or is this what the call an LS swap]not sure if the ecu is the right one, how would i be able to tell? the only other code, is code 5 which seems to be the map sensor.the place on the head where the vtec solenoid control valve goes has a cover on it and there are no wires for it to be pluged in if it was there. maybe i have the wrong harness and wrong ecu but i doubt that because i have no other issues
Old Jun 9, 2019 | 02:37 PM
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Default Re: code 21

Originally Posted by xamdam67
maybe i have the wrong harness and wrong ecu but i doubt that because i have no other issues
How could a non-VTEC engine possibly throw a VTEC code unless the ECU is a mismatch? Please respond.

Logic will always prevail.
Old Jun 9, 2019 | 06:43 PM
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Default Re: code 21

true, now thats the prob, how about you tell me where and or how i can resolve the issue ....hence how do i get a hold of the correct ecu for my car so i can drive and enjoy it
Old Jun 9, 2019 | 06:56 PM
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Default Re: code 21

Start by reading the label on the ECU. Then look to see what ECU you have here:

http://www.phearable.net/information...daeculist.html

Keep in mind that an OBD1 ECU can be chipped to run many different types of engines, so you may also need to open the ECU and look for a chip.

Code 5 is generally a vacuum hose issue or mechanical issue with the MAP sensor, so carefully inspect them.
Old Jun 9, 2019 | 09:48 PM
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Default Re: code 21

Originally Posted by xamdam67
not sure if the ecu is the right one, how would i be able to tell?
Originally Posted by muellersfan
How could a non-VTEC engine possibly throw a VTEC code unless the ECU is a mismatch? Please respond.

Logic will always prevail.
To be fair, he didn't disagree and did ask the first time around.
Old Jun 10, 2019 | 05:22 AM
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Default Re: code 21

Originally Posted by TomCat39
To be fair, he didn't disagree and did ask the first time around.
Missed it.
Old Jun 10, 2019 | 05:42 AM
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Default Re: code 21

To be fair he missed it by a mile
Old Jun 11, 2019 | 07:49 AM
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Default Re: code 21

um ok took the ecu out and it says ....p28.. which means its NOT the correct ecu for the engine also i opened it up and low and behold it does have a chip in the place where the vtec chip is supposed to be therefore must be the wrong ecu as you instructed does that mean that the engine that used to be in this car was a vtec if so shouldn't there be a wire or plug to be used to plug into the vtec solenoid valve like i said i bought this car from someone who didn't know what they were doing or just didn't care now that is resolved where do i get the CORRECT ecu for this car???
Old Jun 11, 2019 | 08:19 AM
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Default Re: code 21

Originally Posted by xamdam67
um ok took the ecu out and it says ....p28.. which means its NOT the correct ecu for the engine also i opened it up and low and behold it does have a chip in the place where the vtec chip is supposed to be therefore must be the wrong ecu as you instructed does that mean that the engine that used to be in this car was a vtec if so shouldn't there be a wire or plug to be used to plug into the vtec solenoid valve like i said i bought this car from someone who didn't know what they were doing or just didn't care now that is resolved where do i get the CORRECT ecu for this car???
The chip can be removed and replaced with one that matches your engine.
Old Jun 11, 2019 | 08:40 AM
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Default Re: code 21

Originally Posted by muellersfan
The chip can be removed and replaced with one that matches your engine.
first you say one thing then totally another still without answering my question WHERE CAN I GET ANOTHER ECU THAT FITS WITH THE ENGINE THAT IS IN MY CAR and or which ecu FITS WITH THE ENGINE IN MY CAR
Old Jun 11, 2019 | 02:02 PM
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Default Re: code 21

Originally Posted by xamdam67
first you say one thing then totally another still without answering my question WHERE CAN I GET ANOTHER ECU THAT FITS WITH THE ENGINE THAT IS IN MY CAR and or which ecu FITS WITH THE ENGINE IN MY CAR
Old Jun 11, 2019 | 06:06 PM
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Default Re: code 21

Originally Posted by xamdam67
first you say one thing then totally another still without answering my question WHERE CAN I GET ANOTHER ECU THAT FITS WITH THE ENGINE THAT IS IN MY CAR and or which ecu FITS WITH THE ENGINE IN MY CAR
Sorry that you don't seem to understand. IF the ecu is truly chipped, the programming of the chip could very well be for your motor. Or at the very least is a basemap for your motor and is there to be tuned to your exact engine which is a cost itself.

Google your motor ecu and you should see results of the ECU you need if that is the direction you wish to go.
Old Jun 11, 2019 | 08:07 PM
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Default Re: code 21

Originally Posted by xamdam67
first you say one thing then totally another still without answering my question WHERE CAN I GET ANOTHER ECU THAT FITS WITH THE ENGINE THAT IS IN MY CAR and or which ecu FITS WITH THE ENGINE IN MY CAR
Ok OP... you have two choices: 1) Find a B18B ECU (Part number: 37820-P74-A01 or 37820-P75-A01) OR 2) Contact Pherable or Xenocron and order a basemap chip from one of them... you can use their online order form. Once you get it, you would simply open up your ECU and swap the 28-pin chip that is currently in your P28. This choice assumes that your P28 ECU is fully functional and has no electrical issues.
Old Jul 5, 2019 | 05:46 PM
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Default Re: code 21

a month later now and working on the same car with another problem so the engine is NOT a b18b1 as i was told , it is a zc d16a1 with a black valve cover ,out of an 88 intergra, so i guess this a rare one i put in the ecu that was suggested [p75] and it ran fine no codes no engine light . is this the correct ecu for this engine? the release valve on the water outlet broke and i am trying to find a new one or one that is compatible for this engine seems that it has been discontinued and cannot order it the part # is 19315-pg6-010. is there another model of car or engine that uses the same outlet ?
Old Jul 5, 2019 | 06:03 PM
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Default Re: code 21

That part number is not found on any of the US OEM part sites.
Are you maybe missing a digit in the first group of numbers?
Old Jul 5, 2019 | 06:15 PM
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Default Re: code 21

er'body back the f up, this guy needs to identify what engine he has, in what car, running what ecu. PICS OP.
Old Jul 5, 2019 | 09:40 PM
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Default Re: code 21

Originally Posted by tony_2018
er'body back the f up, this guy needs to identify what engine he has, in what car, running what ecu. PICS OP.
Yeah I wanted to look up all the cars the part was used in but the part number supplied does not populate on USDM oem sites.

It still will be discontinued for all the cars it's used in but at least then there is a full list of years, models and trims the part was used in for salvage yard hunting.
Old Jul 6, 2019 | 12:48 PM
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Default Re: code 21

Please check your block where the block meets the transmission in the front left of the car (when you are standing looking down at the engine with the hood open).
There will be a little flat space that has a stamp with letters and numbers.
Please take a picture of that and post it here or read it and report it to us.

P75 is not the right ECU either. The DOHC ZC engine isn't a USDM engine at all (actually neither ZC came to the USA) and the ECU would definitely not be P75.
Both of those engines are OBD0 engines.

If it is working with an OBD-1 Harness (the harness that a P28 uses) then it has a harness conversion or its not that engine.

You can just get a chip for the P28 which can run the non-vtec engine.

Please refer to this page to see which ECU you would need.
https://www.hondata.com/tech-ecu-identification

P75 is a OBD-2 ECU for a B18B1.

PM7 : 89-91 DOHC ZC (JDM 'EF' ECU)
^ If you do have a JDM DOHC ZC
Old Jul 8, 2019 | 12:43 PM
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Default Re: code 21



the item on the left i took of the zc engine

the item on the right came off a 98 acura integra

it is right below the distribuator


ok here are your pictures you requested for the zc engine i also put in the photo of the water outlet i need for this engine i hope you all can hewlp me with this aswell as what ecu i should be using with this engine
Old Jul 8, 2019 | 01:17 PM
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Default Re: code 21



try again 2 more pics for yall
Old Jul 8, 2019 | 01:30 PM
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Default Re: code 21

https://en.wikipedia.org/wiki/Honda_D_engine#DOHC_ZC
Old Jul 8, 2019 | 01:57 PM
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Default Re: code 21

Alright so that is a JDM DOHC ZC.
That means you need a PM7 ECU to run it properly.
Or you could use a chipped P28/P06/P08 with a ZC basemap.
Old Jul 8, 2019 | 01:59 PM
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Default Re: code 21

Originally Posted by Jimster480
Alright so that is a JDM DOHC ZC.
That means you need a PM7 ECU to run it properly.
Or you could use a chipped P28/P06/P08 with a ZC basemap.
Assuming the ZC DOHC block is mated to a ZC DOHC head.



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