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 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.

 

Did you get a counterfeit KPRO?

http://www.hondata.com/kpro_counterfeit.html

 

ECU was dropped off at RLZ Engineering by me and dropped shipped back from Hondata. The car has been up and running about 7 times now since receiving the ECU. I have uploaded a base tune to get the car started and all. So if it is fake, they got me good!

 

I have checked the main relays that I have according to the tests that are located in this forum. I have also checked the main relay connector/harness to some tests 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.

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.

 

I am walking through all of the wiring to make sure nothing has happened with the engine harness. It doesn't make sense that the car ran, but now after small changes not relating to the ignition or main relay the ECU will not even power up.

 

Check the grounds at the thermostat housing. The main relay and ECU won't work if those grounds are not present.

 

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.