Hondata

Hello. So I have a 2000 Civic lx with a d16y7. Converted to obd1, 3 wire to 2 wire iacv and everything. Installed the s300 V3 on a p06 ecu, had it street tuned before dyno session, everything working well except two things.

1. Check engine light would come on normally when turned key to position II, then would not turn off, only stay dim the whole time. No codes thrown, just dim CEL.
2. ECU was faulty and would have a delay sending signal to the main relay and pump prime (led by usb on s300 would blink red once and turn green as signal was finally sent). Changed all caps on ecu and issue persisted.

I just got a "new" p28, installed the s300 on that ecu. Pump primes, car turns on and drives as it should, but I still get the constant dim CEL. I did not change any caps on this ecu yet, all are still the original nichicon caps.

Any ideas?

IT could be an issue in your vehicle. You should try the EUC in a known working vehicle to see if it works as it should.

I'll see if I can find somebody near me to try that. Maybe the obd2b to obd1 conversion harness? The car was perfect when running on the stock p2e ECU. I did read somewhere that having sensors plugged in that the obd1 ECU doesn't recognize will cause a solid CEL. I just couldn't find anything regarding a dim CEL.

Solved! I remembered I had installed a few T5 LEDs on my cluster, including the CEL. Switched it with a halongen bulb, and the problem is gone. For some reason the LED was getting enough current to keep it dim with the obd1 ECUs and not with the p2e.