'06 Immobilizer/ Horn Issue (1 Viewer)

[elk]

So it has been a while since I was last on the board. Family, work, and winter have prioritized time and my '06 has been sitting since October. I last fired it up about a month ago. I tried to do this again today, but the battery was dead.

I pulled the terminals, set the battery on the charger, got everything up to spec and the moment I reconnected the terminals, the horn starts honking. Ok, this must be the immobilizer. I pulled the 25amp EFI fuse and replaced it with a new one. Same issue. I pulled the horn fuse to get a moment to analyze, now the secondary buzzer is raising the alarm.

I'm running out of daylight and it's getting cold again. Should I cobble together an immobilizer bypass circuit, or am I looking at the wrong issue? I was under the impression that the known immobilizer fault would not honk the horn. The experience of anyone who has gone through a similar situation would be appreciated.

Clearly there is a short or fault somewhere because the battery was drained to 7 volts and it was new in the late summer. I will chase that down once the horn problem is solved.

 

[medtro]

Try turn the key to ON before you install the battery, or turn the key to ON while the horn screams.

 

[elk]

Try turn the key to ON before you install the battery, or turn the key to ON while the horn screams.

I tried the latter to no avail. I'll.give the former a shot. Thank you.

 

[elk]

I tried the latter to no avail. I'll.give the former a shot. Thank you.

Neither option worked. I'm back to square one. Something is triggering the alarm circuit. I'll pull the fuse for the horn again and try to find the secondary horn for the immobilizer, then disconnect that to see if it will start. If it does, then back to the immobilizer bypass.