So I purchased a preprogrammed used ECU from Flagship One. Installed it and it didn't work so I had to send it back so they can look at it. In the meantime, I put my old ECU back in and it gave me codes 1610 and 1611. Security light stays on when key is in the on position, it cranks but won't start. Pull the key out and the security light blinks like normal. The keys still unlock and lock the doors(also put in a new battery for transponder) so is it safe to say they are still programmed? My car should recognize my key, its the original ECU! I saw in the Body, Lock and Security section of the service manual, did the turn the ignition on then wait 5 seconds, turn it off and wait 5 seconds three times and the security light still stays on with key in the on position. Anyone know how to cure these 2 codes without a scanner? Is there a fuse i need to check? Is there a pedal dance I'm missing?

If your IMMU shook hands with the new ECM then it probably can't talk to the old ECM anymore. The P1610 is a lockout code, meaning you tried to start the car more than 5 times with an invalid key. The P1611 means the IMMU is sending no key code or an invalid one. The fact that the fobs open the doors doesn't mean anything, on steel key cars the RKE and NVIS systems are completely separate. You need to get the keys reregistered to get the ECM and IMMU back on the same page.

By re-registering, is that the stick the transponder into the keyhole and quickly remove and repeat 6 times until the hazards flash, turn the key into the on position and press the unlock or lock button on fob and its reprogrammed procedure? Because I did that and the security light still remains on and the codes remain.

No, that's for RKE on the fobs. I doesn't do anything for an NVIS issue.

Ok, is there a way to rectify this issue?

Locksmith, dealer, or a scanner that can register keys.

VStar650CL wrote: ↑

Sun Oct 22, 2023 10:02 am

Locksmith, dealer, or a scanner that can register keys.

+1