PKH34 Operation

Does a PKH34 learn the transponder chip code and mimic that through the data wire -Or- Does it learn the data signal that the transponder reader sends and in turn uses that data signal to fool the ecu? I have an 06 civic (viper 5101 + pkh34 installed 8+ yrs ago) that recently had a dead battery. I charged in car, seemed like it wasn't going to revive at first but took charge after several hours. I tried key starting car only to find green transponder 'key' light flashing on dash. Most of what I've read typically points to the need for key reprogram to car. Locksmith showed up to reprogram, ecu won't take, end up with an error. He got back to me later saying we need to remove r/s & bypass/key. I informed him I had unplugged bypass before he started and that it doesn't house a key, that it is data wire only. We're both stumped. 5101 will still r/s car, pkh34 is apparently still operating correctly. Key in, turn to ON and drive away. If I use normal key start, it turns over, won't fire, transponder light flashes. Trying to learn its operation to'flow chart' this thing. Thank you

are you sure it's not a PKH3? if it is, there is a ignition cut, and that might be what is stopping from a "key" start. have a look at the bypass, the PKH3 will have a jumper, while the PKH34 doesn't. The Jumper is used to program the Key

Sticker on it says pkh34. Not aware of a jumper, has a button. Can't imagine it's the bypass causing the issue considering it was unplugged at the unit(red, black, Brown, purple, I believe) pulled the harness connection right out of the bypass box.

ok if the sticker says PKH34, I won't doubt it. My questions are 1)if you unplug the bypass, the car won't start with the key? 2)if you plug the bypass in it will remote start? 3) do you only have one key? I assume the key use to work to start the car ?

If I try to start with key it only turns over, never starts and green transponder light flashes on dash. This is with the pkh plugged in and unplugged, doesn't matter. Car will remote start still, and then I can insert key and turn to ON and drive. If key is inserted and turned first it doesn't like it and won't let it remote start, it will only turn over not fire. I have two keys, neither work. I'm wondering if the transponder reader ring is messed up. I removed it and key turned to ON does the same, green flashing light. Perhaps the reader isn't seeing the keys anymore. Much of what I read states that low/dead batteries can sometimes make the ecu lose the key codes and needs reprogramming, however it seems this might not be the case.

I would also suspect the transponder ring isn't reading the keys.. since you are able to remote start the car with the bypass, the "data" the ecu gets from the bypass is valid. I would suggest you get a new transponder ring from a junk yard and try that. I assume you checked the fuses, and the transponder is getting 12v and ignition?

I have metered all fuses, but have not checked for power at the transponder reader ring. However, I was turned onto a tsb on a different forum that seems to fit the situation exactly. https://f01.justanswer.com/pyZ...161549_civic_jump_start_06.pdf Honda tsb 06-036 I then started to search for info on the MICU and immediately found a thread that talks about door activated map lights staying on all the time, and it being an issue with the MICU. The night after the locksmith tried reprogramming keys I walked by my front door and noticed the lights were on in the civic, was this exact issue. So that, plus the tsb pointing to the MICU for my no start issue tells me that's the direction I need to head.

To update, because it's frustrating when people don't lol I ended up replacing the driver's side MICU with a used one. Brought it to a dealership and they reprogrammed/registered it to the car as the tsb states.  All is well now, starts with a key like a normal vehicle... Paid $84 shipped for the used unit, 1 hour labor @$115 for the 5 minute program procedure.