foxj0001

Hello all. My '96 tt sits in the garage most days, it's my sunny Sunday car. Usually locks/unlocks and fires up without issue. Today key fob was able to unlock the car but not start it - immobilizer was still active and fob would not inactivate it as usual. Fob would also not even re-lock the car. I replaced the fob battery but no effect; second fob would not work, either, and when I used the hard key to lock/unlock the door it set off the alarm system. I followed the procedure to pause the alarm while entering the key code to disarm the immobilizer and was then able to start the engine. However, with the engine running, the alarm went off again! Maddening. I have searched a lot of threads here on malfunctioning immobilizers and alarm control units but was unable to find any that matched the problem I am having.
Of course, it is Thanksgiving today so forget about getting "commercial" help. Any ideas from you RL'ers?

budge96

If I can make a suggestion and inquiry at the same time was the car on a trickle charger of any kind ?
It may be as simple as a low charge battery seems when sitting for long periods and a full
Charge not maintained the alarm tends to do all sorts of odd tricks just a suggestion, Bert

foxj0001

Thanks for reply.
No trickle charger (own one but no outlets in my condo garage:-(....). New battery (2 months old) and no hesitation to crank when immobilizer inactivated w/code. After alarm turns itself off after 4min I get the LED double flash of an alarm system sensing "something wrong/open".

msw

try removing fob battery…clean terminals inside fob w sand paper/steel wool…and replace battery

Opo

+1

TMc993

...and when you replace the battery, bend the metal contact in the fob out so that there's a tight connection between it and the new battery.

foxj0001

Yup, did all that re: fob. Can't get alarm system to reset.
Thanks for replies.

OverBoosted28

Another step on any electrical contact, is dielectric grease. Helps reduce oxidation/corrosion that can cause some faults. I do all contacts.

budge96

Possibly try cleaning the battery terminals on the main battery to insure contact is not obstructed due to dirt or grease if not already checked.
You mention one of the fobs did nothing do you think it became cleared of its code?
You also mention re entering your alarm code ? Are you talking about the alarm setting sequence with the key ?
That shouldn't be done but when recoding fobs that alone could disable disorient the system
I would only recommend that when coding a new fob, but hey I've only done it a few times
At that, hope you get some progress, thanks Bert

foxj0001

Moral of the story: try the simple things first. It was the fob battery after all!
Those of you advising me to (re)check the fob were right.
Details:
Should have believed the Duracell packaging that said my spare 12V fob battery was good until March 2015. "Who believes expiration dates?" I told myself. Believe them, brother, perhaps especially when you pack 12V of potential into a small 21/23 class battery case...
Got my multimeter out and checked the "newish" battery. Was making

foxj0001

(somehow my last reply got cut short)
Moral of the story: try the simple things first. It was the fob battery after all!
Those of you advising me to (re)check the fob were right.
Details:
Should have believed the Duracell packaging that said my spare 12V fob battery was good until March 2015. "Who believes expiration dates?" I told myself. Believe them, brother, perhaps especially when you pack 12V of potential into a small 21/23 class battery case...
Got my multimeter out and checked the "newish" battery. Was making

foxj0001

Got my multimeter out and checked the "newish" battery. Was making less than 10V. Second fob battery making under 11.5V.
Got a fresh (2019 expiration date) battery from the hardware store and once in the fob I was able to reset the alarm system, gain entry to the car and fire up th engine with the usual (Fister Stage III) roar - never thought I would be so happy to hear that sound!
Thanks friends for the helpful replies and remember, eliminate the simple stuff before assuming the worst and embarking on any expensive and time consuming adventures!
Jonathan

foxj0001

Pix of the little darlin'.

993c4_Toronto

Happy ending. She's a beauty by the way.