Hondata

I'm trying to troubleshoot a malfunctioning MIL light (it is stuck "always on"). I've got a K-Pro mated to a CTR ECU, which is interfaced to a JRSC'd K20A. My current (factory) ECU documentation says the following:

Pin E1: IMO FPR (IMMOBILIZER FUEL PUMP RELAY)
Desc: Drives PGM-FI main relay 2
Behavior: 0V for 2 seconds after turning ignition switch ON (II), then battery voltage

Pin E31: MIL (MALFUNCTION INDICATOR LAMP)
Desc: Drives MIL
Behavior: With MIL turned ON: about 0V; With MIL turned OFF: battery voltage

Currently, both of those pins measure 0V (GND), regardless of whether the ignition is off, just-on, has been on for >1 minute, or whether the engine is running or not. The engine otherwise seems to run just fine. With the ignition off, a multimeter shows about 2kOhm of resistance between either E1 or E31, and ground.

My question is this: what is the expected behavior of pins E1 and E31 with the K-Pro attached? The K-Pro user guide makes a mention that the MIL light (E31) should be "on" (E31 = 0V) for 2 seconds after switching the ignition to "on", and "off" (E31 = battery V) thereafter. Datalogging shows that the MIL should be "off", yet E31 remains at 0V. For pin E1, the factory docs say it should do the same thing - 0V for 2 seconds, then battery V thereafter. It, too, remains at 0V. I have the immobilizer disabled in the K-Manager "Misc" parameters tab, if that makes a difference. Does the K-Pro change the behavior of E1?

Any and all assistance that can be offered is highly appreciated!

Have you tried datalogging and looking at error codes? MIL functions is the same as stock.

Yes, there are no fault codes (and hence the MIL is indicated by KManager as "off"). Is E1 supposed to function as stock as well?

I figured it out - E1 and E31 are "open collector" and are incapable of providing 12V at the pin. They require an external pull-up. Everything seems to work okay now!