When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
My alarm LED lights are double-flashing, which indicates that the alarm is not fully set. My understanding is that the alarm checks the hood, engine lid, both doors, and radio and if all are closed (radio accounted for) the LED lights will single-flash, once every 10 seconds or so. My car used to do this.
About 2 months ago, I started having a weird situation with the radio (aftermarket Pioneer, I hate it, it's on the replace list) where the sound would cut out after 5 or 10 minutes (although the head unit would stay on/lit up.)
Last week, my battery died. Before it stopped working, I noticed the double-flash.
New battery, still getting the double-flash. The car drove fine last night and everything worked properly, except for the double-flash. I'm putting the car in storage with the battery disconnected this friday.
My questions:
1) Can someone, with the appropriate tool, interrogate the alarm or other systems and find out what is prompting the double-flash? I suspect it's the radio but it would be nice to know for sure.
2) Would a faulty radio and improperly set alarm drain the battery over time?
2.a) How much does a double-flash alarm state draw from the battery compared to a single-flash state?
I did some searches and learned a lot of things, but still have these questions.
My alarm LED lights are double-flashing, which indicates that the alarm is not fully set.
Double flashing indicates a problem with the system
1) Can someone, with the appropriate tool, interrogate the alarm or other systems and find out what is prompting the double-flash? I suspect it's the radio but it would be nice to know for sure.
No special tool I am aware of:
Disconect the battery , let it sit disconnected for a short while and reconnect it to clear any improper state in
the controller
With your engine running the voltage should be 13.5+ Volts,
Just after the engine is shut off it should be 12.5 volts
Any voltage lower than 12 Volts may not adequately power the alarm and cause the flashing.
Check the following for proper function:
Frunk light on and off when frunk closed
Glove box light on and off when closed
Engine compartment light on and off when lid closed
Two interior dome lights on and dim-put to off when door closed or cut out when fob is used to lock doors.
2) Would a faulty radio and improperly set alarm drain the battery over time?
don't believe the radio has anything to do with the alarm or ignition immobilizer unless power for it tapped into one of the lines used by the alarm such as power to the glove box light. The radio should be powered by the OE radio pigtail wires or a fused line directly to the battery. A radio with an external power amp that is not wired properly for shutdown with the radio head can run a battery down.
2.a) How much does a double-flash alarm state draw from the battery compared to a single-flash state?
I'm not sure how to check if the light in the glove box is off when the box is closed, but I have all winter to think about it!
The reason I ask if a faulty radio has something to do with the alarm situation is because the owner's manual states that "The following components are monitored by the alarm: Doors (central locking); front & rear lids; glove compartment; radio; ignition (immobilizer)" See attached scan of a 993 manual which I found here: http://911uk.com/viewtopic.php?p=851211
Reading my manual is how I came up with the idea that the radio might be part of the problem.
Finally, the reason I ask if a double-flash alarm draws more than a single-flash is that my car was double-flashing and then the battery was dead. One theory I had was that perhaps the car kept trying to set the alarm properly (ie, move from a double-flash to a single-flash state) and this constant activity drained the battery. After the research I've done, I doubt that this is the case, but figured that if I was going to ask the Rennlist brain trust questions, I might as well ask all my questions.
I suppose I have two problems and I *assume* they are related, but don't know for certain:
1) Why won't my alarm arm properly?
2) Did some sort of malfunction cause my battery to drain down to an un-rechargeable state? If so, what was the malfunction and how do I identify it?
993Mpls - You can definitely view codes from the alarm module, as well as examine its input signals (like the radio) with a Porsche tester or equivalent. With this information, you should be able to very quickly home in on the cause of the double flash.
Now, as to why your battery drained down --it could be many things that are completely unrelated to the alarm or radio.
A malfunctioning charging system (like from a wonky voltage regulator) could have left your battery in a less-than-ideal state, the battery could have just been old, or you may have a parasitic drain on the battery. All of these scenarios can be tested in a rudimentary way with a multimeter. Are you comfortable checking voltages across the battery terminals?
The door lock/alarm control module stores both fault codes and events. These can be read out with a Porsche compatible diagnostic tool. You might need a Porsche PIWIS/PST2/KTS301 hammer in order to read out events, I do not know if this is implemented in the Durametric or UDT/PDT-999 diag tools.
Any double flash will not increase the current draw in the door lock/alarm control module.
There are several other known culprits for current draw in our cars. The most common is door switch failure. This will cause the interior lights to remain lit, as well as activating a relay or two. (to enable the sun roof/windows to be oprated) Turning off the interior lights will make it difficult to spot a failed door switch.
The best way to find a current thief is to measure the current draw from the battery, and remove the fuses one by one to find the circui, and then, find the fault.
Cheers,
Tore
10-25-2016, 03:08 PM
Alarm codes stored anywhere?
