This follows my thread. I have called a local car electrician, he removed the siren module, opened it and cleaned the board (which was corroded due to the internal batteries leakage). Now, before putting two new batteries in, he told me to try if the siren works (he says that if it doesn’t there is no point in putting new batteries in, the unit just need to be replaced). I plugged the siren in: the doors unlock and the car cranks up (before cleaning the module the immobiliser wouldn’t respond due to the siren module board corrosion). This is the only good point though. Bad points: the alarm led still remains on after i crank up the engine; also there is no beep sound when locking/unlocking the doors. My question to you experts: is it possible that the led and “no beep” malfunctions are due to the fact that the siren module i plugged has got no batteries? Thanks
If the siren unit is faulty, e.g. if the batteries are dead or missing, the LED will stay on and there will be no beep. Mine was in the same conditions as yours when I bought the car so I just replaced it. The car actually works even without a siren unit! Stefano
I purchased the siren unit from GM Parts in the US- it is the exact same unit as I removed from my 550 and was around $70.00 about two years ago . I think it came from their SUV. Just plug it in- it even had a fastening bolt in a small cage to facilitate replacement. I have a picture somewhere of the part and package . [email protected]. Oscar
One of our pros said he did the same as your tech on a few alarm sirens by effectively changing the siren batteries, but they all came back. So he gave up and afterwards only replaced the sirens. The GM Corvette siren works, but sometimes has a feature or two missing, like no sound when the alarm is actuated. Replacing the old siren with an expensive new Ferrari unit works best if you can stand the pain.
Taz is correct. The siren will need to be replaced. When the LED stays on, its because of a faulty siren. The security module 'looks' for the siren, and if it does not recognise it, because of an internal fault, it will keep the LED illuminated. As Taz said, the genuine unit is painfully priced.
I recently replaced my GM siren with another GM siren, same p/n. The first one replaced lasted over 8 years. It did everything but scream. The one installed last month does everything the original Ferrari siren did. 575 Bill FL
Here is the actual GM Part number and cost I paid GM (15213135) from newgmparts.com for $76.80 + shipping. Replaced last year and working properly
Bill- Sounds like they made some changes to the siren. Nice to know the latest one will beep and scream. Almost seems to be random earlier on which ones will set off the alarm and which ones will not.
It did seem random how alarms behaved in different cars. A wild guess is now that the part has been around for a while the manufacturer is making a one size fits all replacement. Instead of individualized pieces for different cars the Vette piece may be the same unit in the Ferrari box. We’ve seen this before. Who knows though. I have a 2006 Corvette Z06 (same alarm) as well with never a hint of an alarm problem. Some how it appears the Ferrari eats alarms at a much faster rate. Third alarm for this car, averaging 8 years each. This last replacement did not illuminate the dash light. It did however start causing strange electrical gremlins that all had the alarm in common. Upon replacement everything is as it should be. Bill FL
Bill- Living in the desert does have some advantages. Probably jinxing myself, but mine still has the original siren.
I recently replaced mine with the GM/Bosch unit. Works as it should. Interestingly enough, my DB7 also uses the same unit...
Ordered a new one today. We will see how it goes. The WSM say to take bumper off but posts here clearly shows only passenger headlight removal necessary
Not on a 575 and assuming SA. You will need to pull off the bottom underpanel for access. In my case I’ve removed the headlight for easier access to one nut and the wiring plug, the rest from underneath. It may be possible to do it all from underneath but I haven’t accomplished that yet. The bumper did not need to come off. Bill FL
There are some pics within headlight threads found in the archives. And I believe some in the WSM. Talk to Dave at StickyRX if you need a WSM, his price is right. There are only two nuts and one wiring plug involved in the actual removal of the alarm which is pretty straight forward. Access is a little tight even from the bottom. Taking off the forward fenderwell liner did not provide the needed access either. Headlight removal and underpanel removal are the biggest parts of this job. Bill FL
Ok sorry I won’t be able to offer more for pics. On the 575 once your headlight is out you will see bracing that I don’t believe is on the 550’s. This prevents you from easily pulling the alarm out the top. However you will see it’s right there, you can remove the topside nut and the plug through the bracing. Then you have to go underneath for the second nut. Once finagled from the bracket and removed from the bottom then reinstall the new alarm. You will easily see the alarm from both sides once you’ve seen it from the top. Before you start the job take pics as to how your headlight fits in the car with regard to the gasket along the hood, fender, and front trim. Double check alignment before dropping the hood after the headlight has been reinstalled. You might also note where the headlight mounting bolts fit in the brackets for easier final adjustments. If you have further questions send a PM. Bill FL
I did the job on my 575 removing headlight assy only. It was tight and some fiddling around but with a few choice words of "encouragement" the job was done. As Bill stated the second nut will fight back from topside but I managed to do it. I used the GM replacement also. All functions normal.
Steen please explain further. It wasn’t just about the second nut but removing the alarm between the bracing. It did not fit and accessing other items to move out of the way didn’t seem possible either. From a foggy memory, the only item I can imagine was forcibly reshaping the washer reservoir jar which I chose not to do. If I missed something and there is an easier way please advise. Bill FL
Hi Bill To be honest , I don’t totally remember exactly how I did it. I do remember it was a pain to get the old siren out and the new one in and I remember spending an hour or so on the “second nut”. I think I cut a 10 mm wrench in half to get in the tight spot. I definitely did not bend or deform any parts...not my style. All I can say is it can be done but it may very well be easier to do it from the bottom up. I did not even consider that as I hate taking that darn undertray off without the benefit of a lift and it was the middle of winter in my tight garage.
Take the front inner guard liner out and remove the siren from the bottom it's ie tricky but will come out You will need to remove the headlight to gain access to the bracket to undo the fixings and slide the siren out of the bracket. This can be done with a small ratchet or ratchet spanner.
Thanks Steen for getting back. If or when somebody finds a better way on the 575 please be sure to post details. Agreed dealing with the undertray is not much fun particularly without a lift. Bill FL
Ok job done !! Ordered from newgmparts.com After initial email from them ...nothing. No reply to my emails and no return telephone calls from my voice message Purchased from ebay from dealer in Scottsdale Az. ..got the part in 3 days. Took out the passenger side headlight, removed passenger front tire and inner guard liner Removed the nuts for the gold bracket with open end wrench from the top, pulled the bracket and siren down (together) and just had to pull down the undertray by the bumper/wheel well (see picture below) and twist and turn and out the assembly came. reversed the process job done Tight space but can be done The alarm chirps when arming and disarming. Led light goes out on dash. No scream Maybe better this way Image Unavailable, Please Login Image Unavailable, Please Login
