MIL On No Codes

[jtrue]

I see that I have a MIL light on, but no code. Tried clearing DTCs, Erase ECU(clear security) and re-uploaded MAP, still seeing MIL on with no code. Also tried disconnecting battery, let it sit for a minute, reconnected and same issue.

[jtrue]

ECU Info:
Hondata KPro v4
Serial # 58515
KManager 4.5.1.0
2000 MR2 Spyder
PNF ECU

[Spunkster]

Have you tried the ECU on a known working vehicle to see if it still has a CEL there?

[jtrue]

I have not, but there was no MIL previously. I'll try it in my Civic SI and report back. Are you able to see a code attached to the MIL in the logs somehow?

[jtrue]

Ok, I tested the ECU on my k24 swapped Civic SI(EP3) and MIL wasnt present. I did upload the Civic kal prior to testing. What are the next steps to troubleshoot without a code to reference?

[Spunkster]

If it is not doing it on another vehicle then it sounds like it is most likely a wiring related issue.

[jtrue]

Thanks, I'll try to track pack any changes, I believe I added a hi/lo boost switch recently. I'll double check that it's pinned correctly.

[Spunkster]

What input did you use?

[jtrue]

E29 SCS, looks like it might be related, when I turn the switch on the "low boost" setting I see SCS illuminate and the MIL sensor status turns on. When I flip to "high boost" SCS turns off, MIL turns off. Have you seen this before?

[Spunkster]

This is normal if SCS is used.

[jtrue]

Thanks, glad I realized I made that wiring change, was chasing my tail.