Hi all,

So I've been trying to diagnose an odd problem. I am about to give up, maybe it's time for a new ECU or wiring harness.

I get a CEL about 2-3 seconds after starting the car. Sometimes it's a minute after starting the car. And, I have no VTEC.

I tried to get a code. My wiring harness is sorta hacked up so it took me a while to separate ignition out from main power on the kill switch, and find the diagnostic connector. Anyhow, there's no code and the CEL doesn't light at all when the jumper is shorted. If I turn the ignition on/off the CEL is off again. It only lights up after the motor has been running.

If I cycle power to the ECU, and turn on ignition, the CEL lights up like normal for 2 seconds and then goes off. If I then short the diagnostic jumper, the CEL stays on. This all sounds normal. It's only after it was running and got the CEL that the CEL stays off when jumped.

Any ideas? I don't have a spare ECU unfortunately.

This is a Hondata S100 on a Euro R motor (race car). I have a race in 2 weeks, gotta get this thing fixed!

 

(also, the car runs normal except for the no VTEC. VTEC started getting flaky, and then stopped altogether, and then the CEL finally started coming on.)

 

New ECU? Does this flowchart still apply for Hondata?

 

I'd ask hondata first. Being that there is no code it sounds a lot like some of their crippleware stuff they did on the old stage 2-4 stuff. You can pull the ecu cover and wiggle the connections to the ROM etc. Otherwise, I'd borrow an ecu to test. That would at least tell you if it's the ECU or the wiring/sensors.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by flyrod &raquo;</TD></TR><TR><TD CLASS="quote">I'd ask hondata first. Being that there is no code it sounds a lot like some of their crippleware stuff they did on the old stage 2-4 stuff. You can pull the ecu cover and wiggle the connections to the ROM etc. Otherwise, I'd borrow an ecu to test. That would at least tell you if it's the ECU or the wiring/sensors.</TD></TR></TABLE>

Yeah, wish I could borrow an ECU easily. Looks like I'm towing the car to King to actually read the code out with the logger software. It's probably a bad wire/sensor but I can't get the code. It may or may not be a common thing, to have no codes flashed on the CEL when using Romeditor 4... not sure if anyone else here has seen that but when I called King, they said it sounded like other people were having a similar issue.

-Chris

 

now if you are getting CEL codes and you are trying to pull the cel number and get a blank screen, that is a code zero.

And code zero means bad ECU. It should be in some sort of limp mode.

Now you havr it hooked up to Hondata, so I dont know if they work the same way from a straight OEM ECU

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Acidcrakker &raquo;</TD></TR><TR><TD CLASS="quote">now if you are getting CEL codes and you are trying to pull the cel number and get a blank screen, that is a code zero.

And code zero means bad ECU. It should be in some sort of limp mode.

Now you havr it hooked up to Hondata, so I dont know if they work the same way from a straight OEM ECU</TD></TR></TABLE>

I was thinking bad ECU, but King called Hondata, and they said it was a known issue that you can't read codes out if you use Romeditor 4. Not sure if it's a problem under all circumstances, or just under certain circumstances.

Anyhow, PITA, I'm just going to tow the car up to King and have them read a code. ($100 in gas later!! :S)

-Chris

 

So did you re-burn the crapdata bin file or are you still getting the problem?

Fixed or no?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by PirateMcFred &raquo;</TD></TR><TR><TD CLASS="quote">So did you re-burn the crapdata bin file or are you still getting the problem?

Fixed or no?</TD></TR></TABLE>

It might be that, or a bad sensor, no clue. Going up to King to get it fixed (or at least get a code!) tomorrow afternoon.

 

Fixed.

Code was 21, VTEC Solenoid, but it wasn't the VTEC solenoid or the wiring. The power transistor/switch on the ECU had broken free. The guys at King Motorsports found one, soldered it on and hotglued it into place so it won't wiggle loose again.

Thanks to the crew at King for figuring that out and not selling me a new S100!!!

-Chris

 

Funny I'm going through the same crap right now I got the hondata ecu with the conversion harness built in with a s300. I put the jumper in no code. I start the car after like 3 seconds of runing the cel light pops on. I jump it while it's runing cel goes off. Can't tell if I got vtech or not because I'm runing a open downpipe and it's a built boosted H can't hear it kick in or really feel it for that matter lol I'm stumped no frickin clue what it could be. Maybe I will also be taking a trip to King as well.