The keys to my 5th gen were lost, its a 98 SH and I know the usual if you dont have the red key either find a good dealership to scan the code for you or pay a bad dealership 600$ for a new Immobilizer.

I have an offbeat question though, this car was converted to OBD1 and runs a Chipped P28... would the car start if i had a new key cut from honda? Just curious since the car isnt in my hands right now and I cant just go have a new one cut and test this right away. Car is 3hrs away so I'm theorizing right now...

P28 has no immobilizer, car does have it... would it start?

Anyone have experience with this? thanks

EDIT: reading this back to myself, i am sure it will work...

 

more than likely you need to find ur keys or get it reprogrammed with new keys, i ran/run AEM ems, and now im on neptune chipped p28.. both ecu's required a programmed key to start, i tested this theory, using my 2nd master key and melted the black plastic off, and took out the chip inside it.. and tried to start my car.. and will not crank or prime the fuel pump, with either ecu

so in essence the car will not start

 

why would you melt the black plastic off? sorry not calling bs or anything but it just doesnt seem realistic just to test. i'm going to get a dupe tomorrow but the red key thats required has been lost... i dont have a choice. if the immobilizer isnt present why would it not just turn the car on? i've heard of this working on integras... im going to give it a shot tomorrow, hopefully it works.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 93preludes &raquo;</TD></TR><TR><TD CLASS="quote">why would you melt the black plastic off? sorry not calling bs or anything but it just doesnt seem realistic just to test. i'm going to get a dupe tomorrow but the red key thats required has been lost... i dont have a choice. if the immobilizer isnt present why would it not just turn the car on? i've heard of this working on integras... im going to give it a shot tomorrow, hopefully it works.</TD></TR></TABLE>

bc i wanted to test and learn how immobilizer worked.. i melted the plastic off the chip fell out which is a small glass tube with a coil inside it..

i dont see why thats not realistic to test.. its basically u take a real key with no chip and try to start the car without royally ******* up your ignition... bc the key that was made for the car.. would go in the hole.. turn the car on.. the accessories on.. everything else on.. but would not start the car , or prime the fuel pump.. simple as that

i wanted to make sure that no one would be able to steal my car if they jammed a flat blade screw driver in my igntion key, and turned the car on.. bc i had a stand alone system..

and what i did, proved to me that with another ECU.. AEM EMS standalone unit.. at the time.. i was not able to start my car with my own key, with no chip in it.. i have two master keys, i was willing to sacrifice one.. which i did.. and i still have the rest of my keys so i can always get them made at honda..

thats why im trying to explain, immobilizer has two parts, to it.. and one part is in the ECU and the other is external.. so immobilizier is still present even if you take out the oem ecu..

paul h22a4 can vouch for that.. bc he was with me.. he also lives in austin..

 

There are three pieces to the immobilizer circuit. One is the ECU, second is the receiver, and third is the immobilizer unit itself. The immobilizer unit is to the left (as you're sitting in the driver's seat) of the steering column, under the lower steering column trim piece. It still functions even when the ECU is changed (I have a NepTune P28), so if you don't have a key programmed for the immobilizer, it will not start.

One of the projects on my list is to bypass the immobilizer itself, but I haven't gotten around to it.

 

i've got the same ecu as both of you, neptune p28 but yeah, that pretty much sucks... thanks for the feedback.

 

With the help of a few generous engineers I found a way to bypass the Immobilizer. If anyone needs help with this just shoot me a PM and save 500$+... just updating this in case anyone is ever searching.

 

nice man, im glad you found a good resolution to it!

 

Post up the solution! I guess you could always install a push button to activate the starter, like an s2000. If you can get power to the ECU (P28) and crank the engine, then the car should run fine.

 

It depends. When I had a NepTune P28 installed, the engine would not crank over with a non-programmed key. I jumped the starter cut in the immobilizer unit to get the engine to turn over, which it would, but it wouldn't start. The fuel pump wasn't getting any power. The module has a fuel and starter cut in it.

 

It's odd. For whatever reason my ecu failed. In the time being I had to move my car a few miles. I used a borrowed ls ecu, it starts up fine (using the oe keys). The used p5p I bought just came in today..through it in guessing what would happen, no start. So if the ecu doesn't have any immobilizer circuit, it starts right up.

Fwiw, the car is going to the dealer to get the new ecu recoded. The labor rate is .5hr, ~$50.

 

Yes, part of the immobilizer system is in the ECU. The other portion (that stays active, even with a non-immobilizer ECU) is the receiver that is by the ignition switch, and the immobilizer control unit, which is on the left side of the steering column next to the cruise control module. Those two pieces still work even with a P28 NepTune ECU.

 

I think on OBD1 the fuel pump is powered by the main relay and a signal from the ecu. Does the imobilzer bs replace the main relay? I wonder if it could be as simple as swapping that relay and the ecu...

 

i bypassed my immobilizer by runner an obd1 p13 and using an s2k push button start.