24 Aug 2010

The ECU has been shipped to a guy who specializes in KPro ECUs. He’ll check out the ECU completely to at least get me to a known baseline. As it is, it’s hard to know if it’s the ECU, me, the dash, or a combination. As said before, air/fuel ratio is always stuck, the O2 heater never comes on, and MAP is stuck. It’s possible that I have to run the engine, or run it for a while, to see if these issues resolve themselves. Asking about it on the Hondata forum was frustrating due to the circular reasoning and went something like this:

Me: What’s MAP read when the engine’s off?
Forum: What does it read when it’s running?
Me: I don’t know, I can’t run the engine now, but it appears stuck. I’m going to send it to someone.
Forum: You haven’t even run the engine and you’re saying it’s bad. Try it in a known-good car.
Me: I’d love to but don’t know anyone with one. The reason I think it’s bad is because no one’s answered my question.
Forum: It doesn’t read until the engine’s running, don’t trust the readings until it’s running.

So I still don’t have an answer. Turn on the key, see what it says, how hard is that? Since no one can do that… okay, I’ll figure it out on my own, so, surprise, it’s going out to be tested.

This brings us to the ECU Interface module between the ECU and dash. As mentioned, data is coming out of the ECU at the proper baud rate, so that’s not the problem. The Race Technology rep contacted me today and it’s down to these possibilities: 1. The Interface module expects different data then what’s coming from the ECU, 2. It needs some handshaking it isn’t getting, or 3. It’s broken. I don’t think it’s #2 because it’s supposed to “just work” without any outside help. Assuming it’s not broken, that leaves #1, so looking on the Hondata site, a list was found of the data that’s sent out the datalogging port. Comparing it to what the Race Tech Interface module outputs shows some interesting differences. The Hondata ECU outputs 15 engine parameters, yet the Race Tech Interface outputs only nine parameters… hmmm, what’s with that? So either the Race Tech Interface is tossing out parameters it thinks I don’t want, or it’s rejecting the entire packet because it thinks it’s the wrong length, which, given that nothing’s coming out, seems to be the problem. Awaiting a reply from Race Tech in England…