Hondata

- what vehicle you have - 1991 Civic Dx
- serial number of your K-Pro -
- ECU part number (starts with 37820) and serial number (the number under the part number)
- KManager version (not 'the latest')
- the calibration (as an attachment) - base tune just to start the engine
- a datalog of a problem (as an attachment) - can not datalog because the ECU will not power on and the laptop will not recognize it.
- anything about the car which has been modified from stock which may affect the ECU (don't include what sort of rims you have nor stereo etc). - A lot has been modified. It is lightly built turbo K24 in a EF chassis.
- when and where you got the K-Pro - KPRO was bought just before Christmas through RLZ Engineering and dropped shipped back to me from Hondata
- a specific description of the problem

I have a 91 DX that I swapped a K24 into. I have had the car up and running a few times, but have not driven it yet. So I know that my KPRO works and I know that it is a legit KPRO since I bought it brand new from a dealer. Today I plug the ECU back into the car to fire it up again and the ECU no workie........

I have tested the main relay, by Hondas standards, it is fine.

I have tested the main relay harness, it checks out fine as far I can tell. I also got the fuel pumps to prime by jumping the main relay harness.

I have plugged my ECU into a friends EG and his fuel pump primed and the green light at the USB port illuminated. Didn't start his car up because we did not have a laptop nearby and I didn't want to start his car with my kal.

Plug it into my car and it does nothing, and my laptop is saying that ECU is offline. I have tested for power at the ECU connector and it was getting voltage. Also, the bottom of the ECU gets warm because while I was just out there looking for the problem I picked the ECU up to move it and the bottom was warm. My garage was about 30 degrees on the inside. I left the ignition on with the battery hooked up to try something out, thats when I found the ECU was warm on the bottom.

I have pulled the ECU fuse and tested it with my multimeter, it is not cracked and good to go. I have pulled the alternator fuse as well, it looked good. I have heard on the EF chassis, that those fuses would blow and cause this scenario that I am now dealing with.

I have looked over my wiring on the KTuned conversion harness that I am using, by their directions all is good. And as I already stated, the car has been fired up probably a total of 7 times, just never driven.

The ECU does not illuminate, laptop says it is offline, why is this? I can not figure this out and I have been looking and testing for hours now. I am either overlooking the problem or to dumb to figure it out. As of right now I am at a loss. Someone please help.

If the ECU is getting warm then do not power it up before you fix the problem, otherwise you will damage it.

You will need to check all the wiring is the same as our engine swap diagram. http://www.hondata.com/techk20wiring.html Start by looking at the main relay then the fuel pump relay then the o2 sensor relay.

If you're using the main relay that come with the car, then the wiring is not correct, as the RSX ECU requires a different relay setup than the earlier cars.

Hondata wrote:If the ECU is getting warm then do not power it up before you fix the problem, otherwise you will damage it.

You will need to check all the wiring is the same as our engine swap diagram. http://www.hondata.com/techk20wiring.html Start by looking at the main relay then the fuel pump relay then the o2 sensor relay.

If you're using the main relay that come with the car, then the wiring is not correct, as the RSX ECU requires a different relay setup than the earlier cars.

So, if the wiring is not correct, then why did it work then all of a sudden decide not to work? Thats the part that makes no sense. Also, why would reputable sources sell conversion harnesses for the specific chassis you are dealing with that lets one utilize the wiring and relays that are there? I am using a Ktuned conversion harness for a k swap into an EF chassis.

If I do not need to use my KPRO ECU to remedy this problem, what do you suggest using to test out the car to see if what I am doing is working to fix the problem?

Here is what I have done and will retest today to make sure that my test results were accurate;

I have checked the main relays that I have according to the tests that are located on various forums and apparently pulled directly from a Honda manual. I have also checked the main relay connector/harness with tests from a Honda manual and I have a few questions about them.

MAIN RELAY HARNESS TEST

1. Keep the ignition switch in the OFF position.
2. Disconnect the main relay electrical connector.
3. Check for continuity between the BLACK wire (pin 2) in the connector and body ground.

According to this test I should have continuity between pin #2 and chassis ground, right? I got no beep or no reading on my meter when I tested in several areas on the chassis. Pin #2 should be a constant ground as far as I know, not a switched ground.

Main Relay Harness Test (pins 2 and 5)

4. Attach the positive probe of the voltmeter to the YELLOW/WHITE wire (pin 1) and the negative probe to the BLACK wire (pin 2).
a. Battery voltage should be available.
b. If there is no voltage, check the wiring between the battery and the main relay as well as the ECU fuse (15A) in the main fuse box.

Do I do step 4 with the ignition on or off? With the ignition off I got nothing, with the ignition on I got around 12v

Main Relay Harness Test (pins 2 and 4)

8. Turn the ignition switch to the START position.
a. Approximately 10 volts should be available.
b. If there is no voltage check the #2 (10A) fuse and the wiring between the ignition switch and the fuse box, and from the fuse box to the main relay.

I should also get 10volts when the meter is hooked between pin #4 and pin #2 and the ignition is turned to the START position. I did not get 10 volts or anything on my meter for that matter.

Try the ECU on a known working car first. IF it works correctly then you know it is a problem with your wiring. What have you changed in the car since it last worked?

Spunkster wrote:Try the ECU on a known working car first. IF it works correctly then you know it is a problem with your wiring. What have you changed in the car since it last worked?

I plugged my ECU into my friends car. It powered up and the fuel pump primed. We did not attempt to start his car with my ECU because of the kal I have loaded into mine. We did not have a laptop available at the moment to load his tune into my ECU. But I feel confident that since it seemed to work fine up until starting the car, that it would work.

I am using a K24A1 automatic harness in my car. At first, as I have stated, the car would start fine with this harness. The only problem was it was not wired for VSS or for the reverse light switch on the manual transmission that I am using. The only changes I have made with the harness since the car last started was wiring up the VSS connector and the reverse light connector. I am now in the process of tracing all of those wires and looking over the wiring schematics that I have for the RSX and CRV to make sure of that stuff. I am also thinking that I may have a problem with the wiring at the ignition switch or the switch itself.

Fixed it, found the problem about an hour ago. Earlier today while still doing tests on random electrical stuff I flipped the ignition switch to the START position, the engine tried to turn over then everything died. So for a few hours I wiggled wires, untaped the harnesses, you name it. Finally I got over to where the battery is and started shaking everything and I decided to try a different battery ground. As soon as I loosened the chassis ground the door chime started and things came to life. I moved it to another spot and what do you know everything started to work. Fired the car up again and everything seems fine for now. I guess that ground would work just enough for some things and not enough for others. Kind of weird, but placing the ground in a different location seemed to have done the trick.

Along with the bad battery ground, the VSS wiring was backwards on my harness. I plugged that sensor up and that had the same effect as the bad battery ground. I know that the battery ground was definitely bad and I know that the VSS wiring was definitely backwards. What a relief it was to fix that stuff and have good results. Everything works fine right now.

Hey man, the odds of you seeing this is so low considering it’s been 10 years lnfao but I’m having the exact problem.
My car ran and drove up till a few days ago, when I tried wiring my CSS to VSS since I have a k24a integra. Since then, my Kpro reads ignition as off and my fuel pump Dosent prime and ofc car Dosent start. What exactly did you do to fix yours and how?
Really hope you see this… lol