Any Alternative to disabling Alarm (Unlock car with key - alarm goes off).

[kaede]

Hi,

BEFORE SOMEONE POINTS OUT, i have already searched and had refer to (http://www.nsxprime.com/FAQ/Troubleshooting/antitheft-keyless.htm and http://www.nsxprime.com/forum/showthread.php/25350-How-to-disable-Factory-Alarm) for disabling the alarm by either unplugging the hood switch, or installing the hood latch other way round so that it don't trigger the hood switch sensor.

My NSX is a 94' and I don't believe i have keyless lock (was never given to me when i purchased it, just sets of keys). MY PROBLEM is... seems like my NSX didn't came with that hood switch/sensor thing all together (or, it's been pulled apart by previous owner and never reinstalled). I can take some pictures for reference and post it later if needed.

I know the way to properly FIX it is to technically take the door apart and change door lock switch as per the service bulletin here (http://www.nsxprime.com/FAQ/Reference/tsb/93-007.htm). However, before I drop some money and mickey mouse my way around with the door, is there any other way for me for now to disable to alarm besides the hood switch method? Any one got pictures or directions for perhaps a particular fuse I can pull JUST for the alarm and won't affect anything else? Many thanks in advance.

Cheers.

 

[I_M_Legend]

have you considered disconnecting the SCU?

 

[Honcho]

have you considered disconnecting the SCU?

Beat me to it! Yes, I'm pretty sure you can just unplug the security unit without causing other issues.

 

[Old Guy]

Your car would have had the hood switch sensor - just by the front latch. If it has been removed by a previous owner you need to find the plug that the switch connected to. In order to prevent the security system from arming, that plug has to have a jumper in it so that the SCU reads the hood as being open (hood open - switch closed, hood closed - switch open). If the plug is just hanging loose with no jumper then the SCU reads the hood as being closed and will arm when you lock the car.

The other option is to do the same thing with the switch on the engine hatch. Unplug the switch and put a jumper in the matching plug on the body harness. This will cause the SCU to read the hatch as being permanently open preventing it from arming. The warning light in the cluster indicating that the hatch is open will also stay illuminated all the time.

Both the hood switch and hatch switch options are better as temporary fixes than unplugging the SCU because access to the SCU is not exactly convenient.

 

[kaede]

Many thanks for all that replied!

So i took a look. Found the red one just hanging there (1st pic) and the Grey one (1st pic) was plug into the thing in 2nd pic - which i suppose is a jumper of some sort that you mentioned Old Guy? (Sorry, i am HORRIBLE at electrical and terms, definitely not a mechanic or too hands on of a guy.) Also as you can see in 1st pic, the sensor module that attaches to the latch is all but missing.

Reading what you have wrote Old Guy, you mentioned a jumper needs to be attached to BOTH the red and grey plug?

For now, I disconnected the grey with the thing in the second pic. Which means both plugs in the first pic is just disconnected.

I did try to lock and unlock my car with the key on both doors and see if the alarm will trigger now that i unplugged it - it didn't go off. However, it only sometimes does it so i might still be missing something (or looking at something entirely wrong) and the alarm just happens to not have went off by luck. Please let me know!

 

[Old Guy]

Yes, your car is definitely missing its hood switch. The hood switch would be mounted between the latch and the inlet to the washer bottle. The hood switch connector is grey; but, so are about 200 other connectors on the NSX so I am not absolutely sure that particular grey connector is for the hood switch. The 1997 service manual says that the wire colors on the hood switch connector are black and yellow/green. Those wire colors do not look correct; but, Honda might have changed things during the production run. I don't recognize the black thing is that is connected to the grey plug. It is definitely not a jumper. It looks more like a weird through bulkhead grommet of some kind.

For now, I disconnected the grey with the thing in the second pic. Which means both plugs in the first pic is just disconnected​

What was the grey plug connected to before you disconnected it?

I also don't recognize the red plug. I took a quick look in that area in my car and there was nothing with a red plug; but, it is hard to see stuff unless you take it apart. It might be for the left horn or the connection to the windshield washer pump or the lighting on the left side. There is also a temperature sensor for the air conditioning that is lower in that sort of general area. Is there anything else on the car that doesn't work?

If you want to disable the security system from arming you need to insert a jumper (an un bent paper clip will do) into the two pin openings on the plug shorting them together. This sends a message to the SCU that the hood is open which will prevent the SCU from arming. If the SCU is not arming, something is already blocking it from arming. Don't go inserting any jumpers into plugs unless you are absolutely sure you have the right plug. Insert a jumper into the wrong plug and you might get a very nasty surprise or damage something.

 

[kaede]

What was the grey plug connected to before you disconnected it?

The Grey plug (in the first pic) was connected with the male end of the other grey plug with that weird bulkhead grommet thing (2nd pic) that leads to no where.

Thanks for you insight Old Guy! At this stage maybe I should for peace of mind:
a) take it in to some local NSX specialist and see if they can quickly identify the hood switch plug and put that jumper in/ also decipher what the grey and red plugs are in the 1st pic so nothing is not properly plugged in per say. And or
b) just pony up the money all together and get the door switches replaced also by a reputable shop or NSX specialist at the stealerships.

Any other people who can chime in is welcome if they somehow noticed what those plugs are for etc.

Many thanks Old Guy!

 

[Old Guy]

I am really at a loss on the wiring weirdness that is going on in the front of your car. Somebody got creative in the past.

Good luck with it.

 

[Kaz-kzukNA1]

Depending on the country spec, some models didn't have the front hood/bonnet switch until after a few years into the production but not sure about your spec.

Can't see how the entire loom is running in your 1st photo but the BROWN connector (Wire colour: BRN and BLK/GRN) is most likely to be the one for
the A/C CCU outside air temperature sensor that is exactly what you have in your 2nd photo.

If the wire colour for the Grey connector is ORN/BLK and BLK, then it is for the Left Horn.



From what you wrote, looks like the temperature sensor was connected to the wrong connector.
It's a thermistor so just check the resistance at different temperature.



In the workshop manual, you can find the pin out of the security control unit so it's not that difficult to disable the hood/bonnet switch input.

The keyless entry remote linked with the OEM security control unit was not factory fitted but a dealer fitted option.
Therefore, depending on the market, Honda/Acura authorised manufacture supplied the keyless control unit to the dealer.
Probably Kenwood did it for the LHD Acura. Not sure for the RHD Acura.

For JDM NSX, the keyless controller was listed as genuine Honda accessory and it was from one of the group company, Honda Access.

Kaz