1999 Honda Accord Immobilizer

Michael Mobile Technician Clinton, Utah Posted   Latest  
Case Study
Electrical
1999 Honda Accord EX 2.3L (F23A1) 4-spd (B7XA)—JHMCG6670XC026279
Crank / No Start

I was called to a shop to program keys on a 1999 Honda Accord. The vehicle had a locked up key cylinder and the shop replaced it. In attempts with three scan tools and the AD MVP (wasted token) I was having no luck in programming the keys that came with the lock cylinder. I checked them for the correct chip and they reported the same one as the original key. All the documents I could find suggested that the immobilizer was toast. I was not sure how that would have happened but maybe it was handled roughly when changing the lock cylinder. It was also possible too many attempts with a bad key locked the immobilizer. I suggested to the shop the the immobilizer was damaged. They ordered a new one.

After the new immobilizer was installed, the same problem persisted. I kept on getting the abnormal state message. I then thought maybe the chip keys that came with the cylinder may be different enough to cause the error so I cut a new chip key. Still no joy. At this point I was getting frustrated. This is my third time there without success.

I had been trying to add keys by clearing all the original keys. The tools would not get the vehicle into programming mode. The immo light kept the steady flashing not recognizing the key. I stepped back and decided to give it a different approach. I went out to the truck and cut a metal key. Instead of going into "all keys lost", I went into the add keys function. I set the original chip key next to the metal one. (The original would not turn the cylinder having a different cut.) by using a metal key and setting the original key head next to the cylinder, the key was recognized. I was then able to add the new chip key I cut. The two that came with the cylinder were duds. They would not program.

I came to the conclusion that this model Accord has a system similar to the turn of the century Toyotas that have to be virginized before new keys can be added when all keys are lost. Based on that theory there are several approaches I might take.

  1. Do exactly what I did to solve the problem by cutting a new metal key. (by the way, I tried Aluminum foil the first time out, it did not work this time.)
  2. Use the EZ Flasher and virginize the EEPROM chip in the ECU. (Premium cost for the customer, ECU has to be removed and dismantled)
  3. Clone the original key. (Clone keys are about 2X to 3X the cost but are copied easily. Clone keys can create problems for the next guy)

Hopefully my bad experience will help others that run into this save time by knowing what to do.

-Mike

+6
Benjamin Diagnostician
Murfreesboro, Tennessee
Benjamin
 

I have run into this exact scenario before. The keys that came with the replacement cylinder where to be cloned and wouldn’t work. I have also had to pull the ICU to the side and hang the keys to be registered into the ring while using a dud key to turn the ignition switch and this would only work by adding a key using one of the originals that would no longer turn the lock cylinder.

+2 Ð Bounty Awarded
Anthony Technical Support Specialist
Kirkwood, Pennsylvania
Anthony
 

Some of the aftermarket replacement cylinders aren't even that. A couple of years ago, a guy with an HDS called me because he couldn't learn the keys. Since I was deadheading back near where he was at, I told him that I'll stop by. Both keys, together, didn't weigh as much as the original key. I told him to put an OEM cylinder with keys in it. He said that they are one-way screws. I replied

+1 Ð Bounty Awarded
Bob Owner/Technician
East Longmeadow, Massachusetts
Bob
 

I had the same problem on a CR-V. The lock cylinder was purchased from amazon and there was a note inside that specifically said that the keys MUST be CLONED. Two locksmith shops near me tried to clone them and said their machines could not read the keys and they spit out some error code. At this point I had nothing to lose so I grabbed my autel scanner and performed the add key function…

+2 Ð Bounty Awarded
Mike Owner/Technician
Asheville , North Carolina
Mike
 

If you erased all keys and then installed an new immobilizer that had never seen the old keys then I don't see how using an old key would work on either immobilizer. Just curious.

0 Ð Bounty Awarded
Benjamin Diagnostician
Murfreesboro, Tennessee
Benjamin
   

I believe the ECM stores the correct key info on these. The Receiver powers the chip in the key and sends this info to the ECM. If you select all keys lost, but are unsuccessful registering the new keys then nothing changes in the ECM. Therefore you could still use an original key to perform the “add a key“ process.

0 Ð Bounty Awarded
Mike Owner/Technician
Asheville , North Carolina
Mike
 

The reason for erasing keys is that lost or stolen keys could not start the vehicle, seems odd that after you erased all keys then the original would start the car.

0 Ð Bounty Awarded
Michael Mobile Technician
Clinton, Utah
Michael
 

Hi Mike, The software did not succeed in erasing the keys or adding new ones. In the end it was very good for me that the erase procedure did not work. It appears that this particular model does not allow erasing keys only adding additional ones.

0 Ð Bounty Awarded