I have a 98 Accord that periodically won’t start. I can tell if it’s going to start or not; the green key light in the dash will come on solid if it will start and won’t come on at all when it won’t.

I had intended to just bypass the ECU by removing the daughter board as described in other forums, but the ECU in this car doesn’t have any daughterboard as described.

At this point it seems like I’m left with either replacing the immobilizer receiver on the ignition switch or the ECU to deal with this problem. Replacing the receiver doesn’t really bother me but dealing with replacing the ECU isn’t ideal, as I’d rather avoid having to pay to have my keys reprogrammed at the dealer if I can help it. I know there are used ECU/ignition switch/key combos available used, but that would require switching the door locks around.

Is there any way to determine which part is causing this issue based on this info, or any path forward I haven’t considered yet?

Thanks in advance.

 

See this link, which supposedly shows the Immobilizer board located in the ECU for a 98 Accord.

Microsoft Word - Honda immobilizer emulatorl.doc (obdii365.com)

 

Thanks for the quick response, this is actually a document I had referenced, but the actual ECU in my car looks completely different.

I attached a couple pictures of what I’m looking at.

 

Does your key have a battery that can be replaced or is it just a chip? I know when my Ridgeline was doing this it was the battery in the key that was weak.

 

As another option, many locksmiths can also reprogram the immobilizer instead of the dealer.

 

Are these early enough to require the red key for programming? I think they might be. The Prelude of the same generation was a red key configuration. Up a creek without that red key.

Especially true with this version of the PCM. The normal green fiberglass circuit boards at least have some options for bypassing. I don't believe there is a bypass option on these weird flexible plastic boards.

 

1. The 1998 Accord doesn't have the red grip learning key. It originally came with two master keys (black grip), and one valet key (gray grip). See attached TSB.

So it is likely a locksmith can program the immobilizer.

2. There is another alternative; but, would be highly challenging. Also, not cost/effective for a one time project. That is turning the Immobilizer off via a Hex Editor programmer of the ECU eeprom bin file.

This site sells solutions via their software and technical help forum. Not cheap.
https://shop.carlabimmo.com/en_US/c/Immo-Bypass/63

Someone requested the fix on their technical help forum for a different Honda Accord ECU model number (with similar circuit board) and was successful.
https://forum.carlabimmo.com/viewtopic.php?t=17857

There may be some other programming sites that may offer something free, which I am not aware of.

 

No unfortunately it’s the older style passive key.

 

This is helpful info. I did find today that if I adjust the steering wheel up and down when it isn’t wanting to read the key with the ignition on that it will read it, the green key light comes on in the dash, and the car will start. So I’m thinking it’s either a wiring issue between the immobilizer receiver and the ECU or the receiver itself.