lukevan

Hello and thanks to all of the contributors on this forum--I have learned a lot from you over the years!

I am having trouble with my mom's '99 Accord LX. Last week somebody unsuccessfully tried to steal it and destroyed the ignition. They also ruined the part of the immobilizer that wraps around the key. I purchased a new ignition from RockAuto that came with the part that wraps around the key, but not the larger (immobilizer?) box that sits on top of the ignition. Today I re-keyed the cylinder so that the old keys could be used that were already programmed to the car. Also, I should mention that the battery was beyond dead (~3V) when my mom found the car the next morning.

Today I charged the battery and plugged in the new ignition switch along with the original immobilizer box. The car cranks but doesn't start. I am getting a continuously blinking green key light as if the car doesn't recognize the key. I don't understand what is going on, since I am using the original keys with the original immobilizer box. Is there possibly memory for the key in the part of the immobilizer that was destroyed and replaced?

I am willing to try whatever to get this figured out, but I am not sure where to go from here. Thank you for any help!!

holmesnmanny

if you replaced either the ecu, immobilizer, or the keys then it all must be reprogrammed by someone with an HDS

poorman212

For giggles, there is an e-brake override you can enter. You will have to get this code from Honda, yes they may give you the "run around" over the phone as they only want to be sure you are not trying to "steal a car"

If nothing else this code will at least let you start the car, assuming the immobilizer is preventing it from starting and there isn't further damage to the system.

holmesnmanny

Accords should be using the brake pedal to apply the brake code.

lukevan

OK, I didn't think that I had replaced the immobilizer since I re-used the box that the green terminal plugs into. And since I swapped the tumblers to match the original keys, I figured they would still be paired up. I read in the attached document from honda that an immobilizer swap does not require a reprogram, is this not true?

I will call the dealership after the weekend and try to get a brake code. In the past, they have not been very helpful for me.

Is there anything else I can possibly try?

tech8

First check under-hood Fuse No. 46 (15A) and driver's side under-dash Fuse No. 1 (15A).

With the ignition switch in ON (II) or START (III),
the immobilizer receiver unit and the PCM or ECM
receive an “ignition on” signal through fuse 46 and
the PGM-FI main relay. The PCM or ECM then
sends power to the ignition key transponder
through the immobilizer receiver unit. The
transponder then sends a coded signal back to the
PCM or ECM through the receiver. If the signal is
correct, the PCM or ECM will enable the car’s fuel
supply system by grounding the PGM-FI main
relay. The immobilizer indicator light flashes a code
to indicate that the correct key has been inserted.
If the ignition key signal is not correct, the PCM or
ECM will not enable the car’s fuel supply system
by not grounding the PGM-FI main relay. The
immobilizer indicator light then flashes a code to
indicate that an incorrect key has been inserted.

If those fuses are good, make sure the car's battery is actually good. You may want to try jumping the car or use a different battery to see if things change.

If not, based on what you described of attempted theft, issue may possibly be due to an open (break) in the wiring or connections from the immobilizer receiver unit to the PCM/ECM. The immobilizer is part of the PCM/ECM; so, unless something happened to the PCM/ECM, no reprogramming may be necessary. Replacement of the receiver unit at the steering column does not require programming.

lukevan

Thank you for the detailed explanation! I will check the fuses this morning. I do have one question though. Would the car be cranking still if the battery were no good?

lukevan

Checked fuses and they were good. Jumped it and same. Just got back from the dealership with my mom and they gave me the brake code. I'll let you know what happens...

lukevan

FIXED!! Got the brake code from the dealer, and that worked to get the car started so I figured I was dealing strictly with an immobilizer issue. On the off chance that the thieves somehow damaged the immobilizer receiver I went to the u-pull and picked one up (along with the rear quarter window) for just over 20 bucks. Got home and it started first try!

Thanks for the help everybody, very happy to have my mom back up and running

holmesnmanny

You're lucky, on newer models replacement of the immobilizer control unit requires programming which allows the dealer to cash in on the theft.

tech8

The Immobilizer System logic is inside the ECM/PCM, even on
later generations.

The receiver unit is not the control unit.

holmesnmanny

On my generation the receiver is built into the control unit.

It shows "With built-in receiver".

It then says after replacement it requires registration.

poorman212

Glad you got it going. Hang onto that code somewhere....I hope you/she never has to use it but since you have it hang onto it.