Hello Guys,

I have a 03 Accord EX Sedan, V6. Long story short, I did some work on it and my ABS-SRS-(!) lights came on. I was following a tutorial on how to bridge the DLC to reset the light. I wasn't paying attention to the numbering on the pins, I was supposed to bridge pin 4 and 9, but instead I bridged pin 5 and 16. I saw a small spark so I removed the bridge quickly, then I tried to start the car but it only cranks and wont turn over - I also noticed that the green key light is blinking as if the immobilizer isn't recognizing the key.

I suspect the key might be bad because when I bought the car I wasn't able to lock and unlock the doors with it...

So my question is, does anyone know what effects could bridging DLC pin 5 and 16 have on the car?

Please and thanks in advance,

 

Hopefully you only blew the fuse (#8 FI-ECU 15amp) when you shorted pin 16 to ground. I attached a pic of the location. Check and replace the fuse. It is in the engine bay fuse box. Hopefully the fuse protected the circuit.

In the future, be very careful when shorting connectors and triple check that you are shorting the correct wires.

 

Thanks for your reply. That fuze was indeed blown, now when I turn the key to On I can hear the fuel pump turning on. However, the green key is blinking on the dashboard still and the car cranks but no start. Could that have knocked the ECU / Immobilizer out of sync ? any suggestions ?

PS* I removed both battery terminals temporarily.

Thanks again!

 

The green light blinking means the electronics are not recognizing your key. The diagnostics require the honda scanner to do parts of the testing.

You may want to test all of your fuses. There is a 10amp fuse under the driver's dash that power the immobilizer system (#7 fuse). You may want to use a volt meter and test all your fuses, since you shorted something you shouldn't have.

The quick way to test fuses is to turn the key to the II position. Use a volt meter and secure the black meter lead to a good ground. Then touch the red meter lead to the top of the fuse where there is a metal tab. Both tabs should read 12V. Any fuse that reads 12V on one side and 0V on the other needs replaced. There are some youtube videos on how to do this test that will help.

Both reading 0V shouldn't happen. It could be a bad wiring and/or a bad fuse.

 

I just tested all fuse and each side gives a 11.4 - 12v reading. I am assuming those are good, so at this point I guess it's safe to say the Immobilizer is shot ? or the ECU ? but if the ECU got burnt, would everything else in the car function fine?

 

I think the functionality of the immobilizer is in the "ECU" (Honda calls it a PCM). Around the lock cylinder is just the RFID antenna for the immobilizer.

And a short that damages the PCM can simply cause local damage to the system that is shorted. It doesn't have to fry the entire PCM, but you never know...

 

So in theory, if it is indeed the Immobilizer portion, which is on the PCM - will that require that the whole PCM be replaced ?

Also, if I get a reader that can check the status of the ECU (Immobilizer, ABS etc) would I be able to tell what is failing ?

Thanks for all the help.

 

I don't know the answers to either question. Just saying that the PCM can be at-fault for some functional failure while everything else in the car that's controlled by the PCM can still work OK.

 

I don't think it's quite that easy. I hate to say it, but you might need to get the vehicle to a Honda dealer, and have them re-program the Immobilizer circuit (it might have lost it's memory). I only say that as I don't think just swapping in another ECU will take care of your problem, unless they send the matching key to the ECU with it. In the 98-02's you have to have a matching key very close by, so it'll start the engine. See the immobilizer is looking for the RFDI chip, and if it's not there, it won't allow the engine to start. If the immobilizer circuit got zapped in the ECU, it probably lost it's programming, which means a trip to Honda irregardless, whether it's to program a new ECU, or re-program the existing one.

Note; if you're looking for an ECU, you need the part numbers off the existing one, along with engine size and type of transmission. Then you can look on e-bay or car-part.com for a replacement. You really want to find 1 with matching numbers IF possible.

 

Way late in reading this.

I know with the 98-02 Accords, there is a code you can enter to override the immobilizer and start the car. You have to get the code from the dealer and then enter it using the e-brake - an example here: Automotive and Commercial Locksmith: Emergency Engine Start Procedure for Acura and Honda

Next, you could call some locksmiths and find one that can program the ECU/PCM to the key, just like you were getting a new key made.