S300 V1 Red LED at D1, troubleshooting

[1slowteg]

I have a S300 v1 installed in a P06 (I think) with vtec, datalogging and boost components installed. I bought this whole package from a dealer about 4 years ago. 2 years ago the S300 V1 would no longer hold a tune (it would reset after I cycled the ignition and had constant red led at D1). I sent the entire ecu to hondata to be tested and the S300 board was replaced with another v1 and everything came back working fine. Everything has been great until now.

Now, upon initial startup the S300 gives me a green light at D1 and the car starts up fine. After 10-15 minutes the car stalls out and D1 has a solid red led instead. Upon cycling the key sometimes D1 will go green and the main relay will click on, other times D1 stays red and the fuel pump will not stay on. I noticed that if I leave the ignition in the on position after 15-20 minutes D1 changes back to green and the main relay clicks on. When D1 is green the ECU seems to work fine and the tune is correct.

Can someone clarify what the red led means exactly so I can understand what is happening?
Is it possible that a wiring issue on the car is triggering this issue or does the red led only point to issues within the ecu?

One thing to note, whenever D1 finally does go green the fuel pump kicks on. and It had one episode where it switched back and forth between green and red 3-4 times while simultaneously kicking the main relay on and off. I swapped the main relay as a sanity check but there is no difference. I would like to do some more troubleshooting before I take the ECU back to my local dealer so that they can check it out for me.

[Spunkster]

It sounds like it could be the capacitors in the ECU going bad. This is common on these ECUs as they are now 20 years old or more. We sell complete capacitor kits to replace them all.

https://www.hondata.com/news/capacitor

[1slowteg]

It sounds like it could be the capacitors in the ECU going bad. This is common on these ECUs as they are now 20 years old or more. We sell complete capacitor kits to replace them all.

https://www.hondata.com/news/capacitor

Thanks.

If the capacitors are going bad, will removing the jumper on J1 make any difference in the way the car is behaving? Or is there a better way to troubleshoot the capacitors?

Can you give me any information on what triggers the red led? Failure in the ecu/failure in the s300/failure in the wiring?

Also, if the capacitors are going bad, should the ECU have a fishy smell?

[Spunkster]

It may have a fishy smell, but it may not. Cutting J1 may or may not make it work differently. The best and cheapest thing to do would be to replace the capacitors. You could also try your s300 in a friend's ECU to rule out an s300 problem, although it sounds like an ECU issue.

[1slowteg]

It may have a fishy smell, but it may not. Cutting J1 may or may not make it work differently. The best and cheapest thing to do would be to replace the capacitors. You could also try your s300 in a friend's ECU to rule out an s300 problem, although it sounds like an ECU issue.

Okay sure, I will be taking this my local Hondata dealer to have them test the ecu and change the capacitors. Hopefully I'll have a positive update after this weekend.

[1slowteg]

UPDATE: My local Hondata dealer confirmed 3 of the smaller capacitors on the board were starting to leak. They swapped my P06 out for another since I was in a hurry and they wouldn't be able to replace the caps for another week or 2. Thanks for the help Spunkster!

Just to note, I ran into another issue that took a while to sort out:

After I got everything back in the car it didn't run the same as before. The afr's were about 1-2 points higher than normal (16:1 idle instead of 14:1). I tried to re-upload my old calibration but then the car wouldn't run at all. Datalogging showed that there was definitely an issue as the AFR on smanager was registering a fixed number, the MAP and voltage readings were also completely wrong. I tried clearing the ecu and upload a new calibration to ensure it had the latest firmware but that made no difference. Under the onboard logging list there were no logs listed but decided to click "delete all" and then a log file popped up on the list. I deleted that log file, cleared the ecu, and uploaded my old calibration and everything went back to normal. Apparently that log file corrupted everything (I am assuming due to the recent new versions of smanager that was released). Hopefully that helps someone figure out their upload issues.

[Spunkster]

If an older version was used to test this out, it may have caused the issue.