Had issues like 2 weeks ago, I was driving and motor shut off and would turn but would not start, also had no communication on the OBD2 port, turns out it was my abs/wheel speed sensor, unplugged that sensor and car was running fine, so with these new cars and all the electronics it could be pretty much anything, I brought it at honda, took them 7 hours to find out that it was that sensor, and 7 hours @ 98$/hr isnt cheap... Good luck..
Hey guys thanks for the responses so far. That's crazy that that ABS sensor not only caused your civic not to start, but also killed communication at the OBD2 connector! As for my situation I doubt it's that, since the center wire at the A/C pressure sensor (greenish-yellow) obviously doesn't flow to the ABS system in anyway. It appears it goes directly into the PCM, thus providing signal to the PCM to engage the A/C clutch on the compressor. However, there SHOULD be a fuse for it SOMEWHERE if this is wired like 99% of other cars out there, but it appears these new civics have no fuse for the PCM? I don't smell fuel when cranking the car either, so I'm going to check to see if the injectors are firing and if there is power down at the pump later on today as I'm at school now. However, even if there is a fuel issue it shouldn't prevent communication at the OBD2 connector. As for dash lights staying on when I turn the key on...I recall seeing the check engine light but can't remember any others. I believe the ABS comes on, showing the system is initiating the ABS check, then the light turns off. I'm going to look into the PGM-FI relays though I have tried swapping them out already. And yes all the large fuses (100amp, 70amp, etc...) in the underhood fuse box are good. Really hope I didn't fry this thing. Open to other suggestions in the meantime, thanks so far!
On nearly all automobiles the OBD2 connector is on the same power circuit as the cigarette lighter/12v port. I deal with this daily at work, and I cuss it every time there's a problem with it. I mean, why the heck wouldn't you give the OBD port its own power connection?
Sometimes those same cig lighter plugs have either a: their own inline fuse behind the lighter itself or b: a fusible link. See if it has one of those if the fuse in the block isn't blown.
Thanks for the suggestion I will check that when I get home today. However...I don't see a blown cig lighter fuse preventing the vehicle from starting. I had some accessories tapped into the power supply on my Maxima when I used to own it and the fuse would blow sometimes, but it never affected the OBDII port or the vehicle's ability to start. I'm ASE certified and worked on vehicles for 5 years before I quit to go back to school, so I really feel like a moron right now
I think it must be something stupid. I mean..think about it...this wire leads into the PCM, but it's obviously not for the starting system, so obviously any wiring inside the PCM that would be in closest proximity to where this wire's pin connects would have to do with the blower motor, clutch engagement, etc...) and not the ignition or fuel system. However, with the key on the blower motor and climate controls work, so now I really think (or am just hoping) it's just a fuse or relay that got fried even though so far I haven't found any bad ones. Any Honda techs here, or anybody know one? I can't help but keep asking the question of WHY the PCM isn't fused when it's such a high dollar item?