H22a with S100, no VTEC, CEL on but no code. (bad ECU?)

Chris F · Post by **Chris F** » Sun Jul 20, 2008 7:49 am

I have an s100 which is probably 6 years old that I use on my race car (Honda Challenge). I haven't changed anything and suddenly at my last race VTEC started dropping out. After 30-60 minutes of running with flaky VTEC, I get a CEL.

Now, 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.

(also, the car runs normal except for the no VTEC, and running a little rough from 6500 up to redline probably due to not being tuned for the low cam)

Post by **Spunkster** » Mon Jul 21, 2008 9:59 am

Since this is an s100 I would recommend taking it to a Hondata dealer so they can try doing some more diagnostics with their dealer s200.

Chris F · Post by **Chris F** » Mon Jul 21, 2008 10:07 am

Spunkster wrote:Since this is an s100 I would recommend taking it to a Hondata dealer so they can try doing some more diagnostics with their dealer s200.

I am in agreement, since all I've been able to do this weekend is poke it with a stick. :) I did try removing TPS and MAP sensors to make sure the behavior changed (it did), so it's not those. Checked wiring to IAT and the distributor and nothing looked out of place. VTEC solenoid checked out fine too.

Should an S100 still blink the CEL light if it has a valid code?

-Chris

Post by **Spunkster** » Mon Jul 21, 2008 10:32 am

What version of Romeditor was it tuned with?

Chris F · Post by **Chris F** » Mon Jul 21, 2008 11:40 am

Spunkster wrote:What version of Romeditor was it tuned with?

Beats me. King Motorsports was the last one to touch it this spring (and it was running fine when it left their shop).

Post by **Spunkster** » Mon Jul 21, 2008 12:01 pm

I would suggest takign it back to King Motorsports to ahve them attempt datalogging the problem with their dealer kit. They should be able to find out if it was tuned with Romeditor 3 or 4.

Chris F · Post by **Chris F** » Mon Jul 21, 2008 12:12 pm

Spunkster wrote:I would suggest takign it back to King Motorsports to ahve them attempt datalogging the problem with their dealer kit. They should be able to find out if it was tuned with Romeditor 3 or 4.

I just talked to them, they are using Romeditor 4. (and I'll probably end up taking it back to them.. wish I could get the code out though!)

Chris F · Post by **Chris F** » Mon Jul 21, 2008 3:05 pm

Chris F wrote:
Spunkster wrote:I would suggest takign it back to King Motorsports to ahve them attempt datalogging the problem with their dealer kit. They should be able to find out if it was tuned with Romeditor 3 or 4.
I just talked to them, they are using Romeditor 4. (and I'll probably end up taking it back to them.. wish I could get the code out though!)

What's the minimum I would need to buy to get the codes out myself from a S100? Software and a cable (and/or a S200?) I hate to make this trip all because an IAT sensor wire is shorted somewhere, or the barometric pressure sensor is whacked, or something else goofy.

Towing 60 miles to King Motorsports every time I get a CEL isn't really my best option..

-Chris

Post by **Spunkster** » Tue Jul 22, 2008 9:16 am

If you wish to be able to tune and datalog you will need to upgrade to the s300. It is $445

http://www.hondata.com/s300upgradeform.html

Chris F · Post by **Chris F** » Tue Jul 22, 2008 6:15 pm

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 ECU :)

Thanks for the info on the S300. Are the bin/tuning files compatible across S100 to S300? My impression was no, since the S300 does more, but maybe I'm wrong.

-Chris

Post by **Spunkster** » Wed Jul 23, 2008 9:28 am

you can import a bin file from RomEditor into SManager