1992 NSX ALARN ISSUES!

Joined
29 April 2023
Messages
14
HI FELLOW PRIME MEMBERS! I’VE BEEN A MEMBER SINCE 2011 BUT HAD ISSUES LOGGING BACK SO HAS TO CREATE A NEW PROFILE. I HAVE A 92 PEARL WHITE NSX SO I UNLOCKED THE DRIVER SIDE DOOR, ONCE ATTEMPTED TO START THE ALARM START GOING OFF! I’VE TRIED TO LOCK/ UNLOCK BOTH DOORS BUT UNSUCCESSFUL. I ORDERED A USED SECURITY MODULE JUST IN CASE. ACURA TOLD NE JUST UNPLUG THE SMALLER PLUG FTOM THE SECURITY MODULE AND IT SHOULD START. I TRIED FEW DAYS AGO AND IT DID. YESTERDAY I INSTALLED THE USED MODULE, RECONNECTED THE PLUG AND IT STARTED. THIS MORNING I UNLOCKED THE DOORS AND THE SAME THING HAPPENED! ALARM KEEP GOI G OFF. ANY RECOMMENDATIONS???
 
SO I UNLOCKED THE DRIVER SIDE DOOR, ONCE ATTEMPTED TO START THE ALARM START GOING OFF! I’VE TRIED TO LOCK/ UNLOCK BOTH DOORS BUT UNSUCCESSFUL.
You are not really clear about what is happening. Did the alarm go off when you opened the door or did the alarm go off when you put the key in the ignition and you attempted to start the engine?

The more common problem would be that the alarm goes off when you open the door and that is caused by a problem with the switch controlled by the lock cylinder. This is really easy to check. Lock the car and the alarm should activate - LED in the driver side door starts flashing. Now unlock the door and check the LED. If it is still flashing the switch that sends the door unlocked signal to the security unit has likely failed or there is a wiring problem. If the alarm goes off when you attempt to start the engine or just switch the key to run that is different and unusual. There is a power on signal from the ignition switch to the security control unit. That connection disables the alarm when the key is turned to run or start. It should not trigger the alarm.

I ORDERED A USED SECURITY MODULE JUST IN CASE. ACURA TOLD NE JUST UNPLUG THE SMALLER PLUG FTOM THE SECURITY MODULE AND IT SHOULD START. I TRIED FEW DAYS AGO AND IT DID. YESTERDAY I INSTALLED THE USED MODULE, RECONNECTED THE PLUG AND IT STARTED. THIS MORNING I UNLOCKED THE DOORS AND THE SAME THING HAPPENED! ALARM KEEP GOI G OFF. ANY RECOMMENDATIONS???

You need to confirm whether the alarm goes off when you open the door or when you turn the key in the ignition switch. If the alarm goes off when you open the door (the armed light did not go out) then you likely have an intermittent problem with the cylinder switch or the door wiring connectors or the wiring back to the security unit. A problem with the cylinder switch is the most common problem. The cylinder switch is part of the latch assembly and I can't immediately remember whether the switch is accessible. Removing the latch from the door for repair involves a significant amount of work (the rear window guide rail has to come out) so you absolutely want to rule out other possibilities before going there.

The service manual describes the input tests for the security control unit and doing those input tests may help point out where the problem is.

My final question is that you said nothing about either an aftermarket security system or a retrofit of the OEM keyless entry system so I assumed that you have neither. Either of those systems can contribute to problems with failing to disarm.
 
You are not really clear about what is happening. Did the alarm go off when you opened the door or did the alarm go off when you put the key in the ignition and you attempted to start the engine?

The more common problem would be that the alarm goes off when you open the door and that is caused by a problem with the switch controlled by the lock cylinder. This is really easy to check. Lock the car and the alarm should activate - LED in the driver side door starts flashing. Now unlock the door and check the LED. If it is still flashing the switch that sends the door unlocked signal to the security unit has likely failed or there is a wiring problem. If the alarm goes off when you attempt to start the engine or just switch the key to run that is different and unusual. There is a power on signal from the ignition switch to the security control unit. That connection disables the alarm when the key is turned to run or start. It should not trigger the alarm.



You need to confirm whether the alarm goes off when you open the door or when you turn the key in the ignition switch. If the alarm goes off when you open the door (the armed light did not go out) then you likely have an intermittent problem with the cylinder switch or the door wiring connectors or the wiring back to the security unit. A problem with the cylinder switch is the most common problem. The cylinder switch is part of the latch assembly and I can't immediately remember whether the switch is accessible. Removing the latch from the door for repair involves a significant amount of work (the rear window guide rail has to come out) so you absolutely want to rule out other possibilities before going there.

The service manual describes the input tests for the security control unit and doing those input tests may help point out where the problem is.

My final question is that you said nothing about either an aftermarket security system or a retrofit of the OEM keyless entry system so I assumed that you have neither. Either of those systems can contribute to problems with failing to disarm.
Hey Old Guy, I just came across the same problem. I just picked up my 1992 NA1 with a compustar alarm, I had it parked at home and when my business partner came over, he saw it was unlocked and manually locked it.

When I got back to the car, I don’t know why but I used the key to manually unlock instead of the remote. Doing so set off the alarm and I’ve tried every possible way to turn it off but to no avail. I eventually shut it off with the kill switch but once I turn it back on the alarm continues to blare.

I’ve tried every combination on the compustar remote. I’ve tried the manual valet mode as instructed on compustar’s website but still no luck.

The remote does work (locks and unlocks) while the alarm is going off. I am also unable to start the car.

I would appreciate any insight you can offer that can help me can resolve this. Thank you so much!
 
What is the little red system armed LED in the drivers door doing? Is it continuing to flash all the time which indicates that the alarm is still armed? Have you tried unlocking the car from the passenger side to see if that will disarm the security system? If the car alarm has triggered it would be normal that the car will not start because the security system will be holding the starter cut relay in the open position.

With an aftermarket security system you are kind of on your own. The fact that your car has an aftermarket security system makes it impossible to be definitive about what the problem might be. I also know nothing about the operation of the compustar system. Does it require that you always lock and un-lock the car using the remote (that would seem like a really bad design) or does it normally allow you to lock and unlock the car with the key (which should dis arm the system).

My knee-jerk reaction in cases like this is get rid of the aftermarket security system. The car already has a security system and you don't need two. Anecdotal evidence on this forum points a finger at aftermarket security systems as being the cause of a lot of false alarms and starting / dead car problems. However, in your case that recommendation is tempered by the fact that you have a 1992 (thank-you for including that important detail). The 1991 and 1992 NSXs were the subject of a Technical Service Bulletin issued in 1993 (TSB 93-007) which dealt with problems with the switches in the door latches leading to problems with the security system. This TSB used to be in the Prime Library; but, is no longer there after the web site up-date. @drew might have a copy. The TSB describes testing the latch switches (same tests as described in the service manual) and if it fails the tests the whole latch mechanism has to be replaced. Replacing the latches is expensive and non trivial. It is probably going to be $1500 or more per door if you don't do it yourself.

So, the latch might be the problem because the switch in the latch has failed. This may result in the security system not getting the message that the door has been unlocked which should cause it to disarm. When you open the door this then triggers the alarm. Or it might be that the Compustar system is in failure mode or perhaps the original NSX security system has failed.

So, pick your poison as to where you want to start.
  1. The easiest thing to do is just unplug the Compustar module and see what happens. Depending on how the Compustar is integrated with the existing NSX security system this might resolve the problem and return the car to its normal operation (if the Compustar is the problem). If that appears to resolve the problem you can then decide what you want to do with the Compustar system. Personally I would remove it and delete the harness interface restoring all the vehicle wiring to original condition.
  2. Since you have a 1992 and if you have no maintenance record of the car going through the TSB 93-007 service I might be inclined to check the operation of the driver side door latch switches. If the alarm disarms when you use the passenger side key that might point a finger at the driver side latch switch. This requires that you remove the inner door liner to access the plugs to the door latch so that you can test the operation of all the switches in the latch mechanism. Removing the door liner is a non trivial exercise; but, doable if you have reasonable mechanical skills. If the latch switches test out OK then that points a finger at the Compustar system or the OEM security system.
I don't know whether there is any way to do a diagnostic check on the Compustar system if it looks like it has failed. That is something that you would have to check out. If
 
What is the little red system armed LED in the drivers door doing? Is it continuing to flash all the time which indicates that the alarm is still armed? Have you tried unlocking the car from the passenger side to see if that will disarm the security system? If the car alarm has triggered it would be normal that the car will not start because the security system will be holding the starter cut relay in the open position.

With an aftermarket security system you are kind of on your own. The fact that your car has an aftermarket security system makes it impossible to be definitive about what the problem might be. I also know nothing about the operation of the compustar system. Does it require that you always lock and un-lock the car using the remote (that would seem like a really bad design) or does it normally allow you to lock and unlock the car with the key (which should dis arm the system).

My knee-jerk reaction in cases like this is get rid of the aftermarket security system. The car already has a security system and you don't need two. Anecdotal evidence on this forum points a finger at aftermarket security systems as being the cause of a lot of false alarms and starting / dead car problems. However, in your case that recommendation is tempered by the fact that you have a 1992 (thank-you for including that important detail). The 1991 and 1992 NSXs were the subject of a Technical Service Bulletin issued in 1993 (TSB 93-007) which dealt with problems with the switches in the door latches leading to problems with the security system. This TSB used to be in the Prime Library; but, is no longer there after the web site up-date. @drew might have a copy. The TSB describes testing the latch switches (same tests as described in the service manual) and if it fails the tests the whole latch mechanism has to be replaced. Replacing the latches is expensive and non trivial. It is probably going to be $1500 or more per door if you don't do it yourself.

So, the latch might be the problem because the switch in the latch has failed. This may result in the security system not getting the message that the door has been unlocked which should cause it to disarm. When you open the door this then triggers the alarm. Or it might be that the Compustar system is in failure mode or perhaps the original NSX security system has failed.

So, pick your poison as to where you want to start.
  1. The easiest thing to do is just unplug the Compustar module and see what happens. Depending on how the Compustar is integrated with the existing NSX security system this might resolve the problem and return the car to its normal operation (if the Compustar is the problem). If that appears to resolve the problem you can then decide what you want to do with the Compustar system. Personally I would remove it and delete the harness interface restoring all the vehicle wiring to original condition.
  2. Since you have a 1992 and if you have no maintenance record of the car going through the TSB 93-007 service I might be inclined to check the operation of the driver side door latch switches. If the alarm disarms when you use the passenger side key that might point a finger at the driver side latch switch. This requires that you remove the inner door liner to access the plugs to the door latch so that you can test the operation of all the switches in the latch mechanism. Removing the door liner is a non trivial exercise; but, doable if you have reasonable mechanical skills. If the latch switches test out OK then that points a finger at the Compustar system or the OEM security system.
I don't know whether there is any way to do a diagnostic check on the Compustar system if it looks like it has failed. That is something that you would have to check out. If
Thank you so much for the detailed response. I will look into the information your have mentioned above to see if I have any luck!

I also did some research and seems to be common problem for some people and they said the same, try locking or unlocking the doors with the key to see if it resolves the problem.

Thank you again for your help!
 
I also did some research and seems to be common problem for some people and they said the same, try locking or unlocking the doors with the key to see if it resolves the problem.

Thank you again for your help!

Specifically, lock and un lock from the passenger side to see if it is the switch in the driver's side door latch that is creating the problem.
 
Hey Old Guy, I just came across the same problem. I just picked up my 1992 NA1 with a compustar alarm, I had it parked at home and when my business partner came over, he saw it was unlocked and manually locked it.

When I got back to the car, I don’t know why but I used the key to manually unlock instead of the remote. Doing so set off the alarm and I’ve tried every possible way to turn it off but to no avail. I eventually shut it off with the kill switch but once I turn it back on the alarm continues to blare.

I’ve tried every combination on the compustar remote. I’ve tried the manual valet mode as instructed on compustar’s website but still no luck.

The remote does work (locks and unlocks) while the alarm is going off. I am also unable to start the car.

I would appreciate any insight you can offer that can help me can resolve this. Thank you so much!
You after market alarm is working as it should, locked in the triggered mode with the assumption someone was trying to take your car. You need to reset the alarm unit. Contact the company or reach out to good alarm installers.
 
I agree with @nis350 that it's possible the alarm is locked in triggered mode due to a fault in the unit. On my old Alpine alarm for my 91, pressing the unlock button on the remote would disarm the system and cancel triggered mode. If doing that did not cause the alarm to shut off, either the unit is faulty or, like Old Guy said, it's your door lock switch.

The lock switch issue on the 91 and 92 cars resulted from excess corrosion. The doors allow a ton of water in via the window seals and it's quite a humid environment. Since most owners bought the keyless entry system as an option, no one used the locks and the contacts just rusted. Using the locks regularly can avoid or at least delay this problem. Something to consider.

I'd remove that Compustar and restore the factory wiring to original spec. The NSX security system is quite good.
 
Back
Top