No horn beep with remote locking. Back of FOB procedure does not work

[NorcalQX4]

On my recently purchased 2001 Infiniti I30, I have not been able to get my horn to sound when the FOB is used to lock the doors.

The horn works perfectly when I push the steering wheel.

I am aware of the procedure on the back of the FOB where you push the "lock" and "unlock" buttons simultaneously for several seconds until there is a "switching indicator" whereby the hazard lights flash once and the horn sounds once. This is supposed to indicate that the horn will sound when the remote lock button is pushed, but on my car it does not sound. The hazard lights do properly flash, but there is no horn sound when the lock button is pushed on the remote. This procedure is also set forth on page 3-6 of the owner's manual, which I have studied.

I spent a long time pushing the lock and unlock buttons together, following the procedure on the back of the FOB and the owner's manual, but could not get the horn to sound.

I have also reprogrammed my remote using the "lock doors manually, insert key 6 times in ignition, then acc, then push remote lock button once" procedure. The remote successfully reprograms, but the horn still doesn't sound when the lock button on the remote is pushed.

Could this possibly be an issue with the security horn relays mentioned in the shop manual?

[centralcoaster33]

Interesting. I think you get to choose between flashing lights or horn, not both. So you're stuck on flashing lights? Do those work every time? Perhaps, and this is a slim chance, perhaps your battery is low in the fob? Maybe it can be replaced and you can switch back to horn sounds. It should be the holding two buttons for two seconds procedure as far as I know. That is the switch between the two. If you hold it too long, perhaps you are switching over and back? You should only get lights or horn, not both during the switch I believe and it sounds like you get both, so I'm thinking you hold it 4 seconds or double the time you need to... maybe.

[NorcalQX4]

@centralcoaster23,

I actually replaced the key FOB battery too.

I can set the system whereby the lights flash when the lock button is pushed, but there is no horn sound. I can also set it where the lights do not flash when the lock button is pushed. So, the system works as it should except there is no horn chirp when the system is supposed to be set up for it.

I'm relatively sure that "security horn relay #2" is bad. The shop manual shows the schematic where horn relay"#2 is activated by the entry control unit which in turn energizes the horn relay. If horn relay #2 isn't working, there is no way that the horn relay can be activated to "chirp" the horn. I have 12 volts at the relay socket, so it's probably a bad relay. I'm going to see if I can find one at the local parts store and just replace it. Usually, I would try to test the relay, but I'm nor sure which terminals to apply voltage to, so I'll just take the easy way out and try a new one.

I'll report back what I find.

[centralcoaster33]

You can take a good relay from another spot and swap it temporarily... if it's the same symbol on top (usually same color and size) for your diagnoses. See if you can get the beep with your key button technique. If so, swap it back to where it came from and replace the bad one.

[NorcalQX4]

Ok, just to update, the horn relay #2 was not bad.

The bad component ended up being the "smart entrance control unit" which is a module located to the right of the steering column underneath the dash.

There is a test in the shop manual on page EL-357 where you ground pin 42 and if the horn sounds, the smart entrance control unit is bad. I did that and the horn did sound.

One of the jobs of the smart entrance control unit is to supply ground to the horn relays when you lock the doors. This makes the main horn chirp. So, that's why it wasn't working.

Just to make sure that the ground to the smart entrance control unit was good, I checked pin 43 (black wire which supplies ground to the unit) and there was continuity to ground.

Hope this might help someone else with the same problem.