help! im stranded !

[cancuncaddy]

hello everyone i need a little help could someone please tell me WHERE IS THE VATS MODULE in my 1996 eldorado ..fixed the no start wait 3 minute thing with a resistor... fine for 3 months then the dreaded starting disabled theft system problem .............so went to the electronics place got the pieces and today will build the VATS BYPASS............but where the heck is the VATS MODULE LOCATED!??? AND WHATS THE BEST WAY TO GET TO IT!? THANKS IN ADVANCE FOR THE EXCELLENT ADVICE ALWAYS FOUND HERE AT CADDYINFO!!!

[Bruce Nunnally]

The VATS module is likely to be in the trunk behind some trim, behind the back seats more or less.

However, the VATS bypass is often applied below the steering column if you are not replacing the lock cylinders and keys.

Remember a simple thing to try is some WD40 sprayed on your ignition key and then in/out of the lock cylinder to try to 'wash' it out a bit.

See this discussion: http://caddyinfo.ipbhost.com/index.php?showtopic=24697&st=0&p=189009&hl=vats&fromsearch=1entry189009 that includes a video on VATS bypass of a chevrolet.

Also if you have the 2nd key you might try it; sometimes wear on the resistor pellet on the primary key is part of the problem.

In the same vein, a new key made by a locksmith may work where your key does not due to the new part.

[cancuncaddy]

hey you guys please help where is the theft deterrent module located on a 1996 eldorado .......... please!

[Bruce Nunnally]

I merged these for you and hopefully you will see my earlier response

[cancuncaddy]

thanks for the response bruce but im beyond those steps i did the resistor trick 4 months ago everything fine.....but as serendipity would have it what appears to be a failure of the TDM ........so i researched and found the ecm recieves a 50mhz square wave signal from the THEFT DETERRENT MODULE so i built one of those 5o mhz generators and now am having a heck of a time FINDING THE TDM supposedely its a little silver box under the dash but as of yet havent found any diagrams or expalantions as to how to remove the module help please my car is stranded ....and i think i have the solution but applying it is very challenging!!

[cancuncaddy]

also after delving deeper into researching this thing im a bit confused as whether or not my 1996 eldorado uses the TDM or its is integrated into the BCM and if so what wire of the BCM is the INPUT OF THE 50MHZ SQARE WAVE SIGNAL THAT HAS TO BE SUPPLIED TO THE ECM???? I APPRECIATE YOURE HELP IM IN CANCUN AND THEIR IS LITERALLY NOBODY THAT KNOWS ANYTHING ABOUT MY SUBJECT MATTER...........IM IT! NOW YOURE IT ....THANKS TO BRUCE OR ANYBODY ELSE THAT CAN ANSWER THIS QUESTION .....FREE TOUR OF THE CENOTES WHEN YOU COME TO CANCUN ...ON ME!!

[Bruce Nunnally]

Looks like a small black module in the replacement photos

ACDELCO Part # D1786C {#19116057}

RELAY,THEFT DTRNT CODE 8567

http://www.rmsautoparts.com/proddetail.php?prod=D1786C

[cancuncaddy]

IF IM NOT WRONG BRUCE THAT IS DESCRIBED IN THE PHOTOS AS THE TDM RELAY...THERE IS ALSO A TDM MODULE THATS THE THING I NEED!!!!! IM NOT SURE WHAT THE TDM RELAY DOES BUT ITS NOT WHERE THE 50MHZ MAGIC HAPPENS!!!

[cancuncaddy]

THAT RELAY I ASSUME IS POSSIBLY THE CAUSE ??? THERES IS NO WAY TO PULL DTC WHEN ITS IN ANTI-THEFT MODE!! TO CHECK IF THATS MY PROBLEM .....WHERE IS THIS RELAY ON MY 1996 ELDORADO? I HAVE READ OFHTER THREADS THAT SAY THE RELAY AND THE MODULE ARE LOCATED UNDER THE DASH? AS I HAVE NO ACCESS TO MAINTENANCE MANUALS OR OTHER MEANS OF LOCATING THESE TWO THINGS ...I REALLY APPRECIATE YOUR LEGWORK!!!!!!!!!!

[Bruce Nunnally]

I am a little lost on the actual diagnosis and what you are trying to do, so I am just trying to answer your questions.

Check here: http://parts.nalleygmc.com/showAssembly.aspx?ukey_product=2821236&ukey_assembly=371977 and there is a module called theft deterrent module.

Item 10

16264965 MODULE. Theft Deterrent or Rear/Side Object

MODULE,THEFT DTRNT(EVO MODULE)(ACDelco #16264965)

The theft deterrent relay is below the lock cylinder in this diagram item 8

[Cadillac Jim]

Probably all you need is a new key.

I think that the theft deterrent is built into the IPM in the 1996 Cadillacs. If the problem is with the key or pellet, changing the TDM or the IPM won't fix it.

Read your OBD codes out, write them down, and post them here (see link in my signature block for Caddyinfo how-to page). That will tell whether you need a new key or other repair. If the problem is in the ignition resistor contacts inside the ignition switch, we can tell you how to fix that using a ten-cent resistor from Radio Shack.

[WarrenJ]

. . .also after delving deeper into researching this thing im a bit confused as whether or not my 1996 eldorado uses the TDM or its is integrated into the BCM

My '95 Eldorado used the standalone PassKey system; no TDM there. All theft deterrents in my '98 Eldorado were integrated into the BCM; no TDM there either. In short, I'm thinking it's a pretty good guess you don't HAVE a TDM.

One of these days something is gonna happen that will make you want to buy a service manual. In the meantime we'll have to wait for someone with a '96 manual to chime in.

Good luck,

Warren

[Cadillac Jim]

Modules themselves very rarely give problems. The symptoms you are describing are most often seen when the contacts to the resistor pellet in the key wear out. First, you get an occasional starting delay, and eventually the car will not start at all. The OBD codes will tell us that.

If the problem is indeed loss of contact with the pellet in the key, that can be addressed pretty easily and inexpensively. You can try a new key, repair or replace the contacts in the lock, or you can disconnect the contacts in the lock and put in a resistor of the same value as the resistance in the pellet in the key.

In any case I very strongly suggest that you read out the OBD codes. If you want us to interpret them and make suggestions on how to fix your car, please post them here.

[WarrenJ]

Modules themselves very rarely give problems. The symptoms you are describing are most often seen when the contacts to the resistor pellet in the key wear out. First, you get an occasional starting delay, and eventually the car will not start at all. The OBD codes will tell us that.

If the problem is indeed loss of contact with the pellet in the key, that can be addressed pretty easily and inexpensively. You can try a new key, repair or replace the contacts in the lock, or you can disconnect the contacts in the lock and put in a resistor of the same value as the resistance in the pellet in the key.

In any case I very strongly suggest that you read out the OBD codes. If you want us to interpret them and make suggestions on how to fix your car, please post them here.

Cancuncaddy has already stated he used the "resistor trick" to circumvent the ignition switch problem some months back. He also says he can't read the OBDI codes while the car is in anti theft mode.

Regards,

Warren

[cancuncaddy]

thanks everyone for the terrific help! ok heres where we are at ! months ago recieved the wait 3 minute thing. seemed fine for a while then i noticed while driving a message appeared theft system problem car may not restart but it kept restarting no problem! now if i pull out the resistor it again gives me the wait 3 minutes when and no starter action. when i replace the resistor it cranks and runs for 3 seconds .....sooooo i built a 50mhz signal to replicate the signal for the ecu. and now i cant figure out where to put this all the posts say attach signal wire to ecu output wire of TDM if my car doesnt have a TDM then how do i wire the 50 mhz signal generator ..im kinda anxious because my car is beside the road!! thanks for alll the wisdom!!!

[Bruce Nunnally]

I believe at this point I would have the Cadillac towed home or to my mechanic, and properly replace the ignition tumbler and fix the system as opposed to trying to wire around it.

In the absence of a proper fix I would still try having a new key cut by a locksmith and see if that works.

[cancuncaddy]

good monday morning to all! i have no idea why i eagerly awoke and ran to my pc to view this thread where i was sure to find more information than i could use and certainly at least one CORRECT answer but NO REPLIES has my a little miffed? why ? im positive in the huge pool of knowledge available here SOMEONE CAN TELL ME EXACTLY WHERE IS THE 50MHZ SIGNAL WIRE TO THE ECU LOCATED IN MY 1996 ELDORADO I HAVE MY BYPASS CONSTRUCTED BUT NEED TO KNOW IF THE SIGNAL IS GENERATED WITHIN THE BCM. THEN WHAT WIRE IS IT THAT I NEED TO SUPPLY THE 5OMHZ SIGNAL. ALL THE GUIDES PERTAINING TO THE VATS BYPASS SAY BYPASS BOX OUTPOUT WIRE GOES TO THE TDM. THAT HAS ONLY 3 WIRES ....WELL IF MY CAR IS GENERATING THE 50MHZ SIGNAL WITHIN THE BCM THEN WHAT WIRE IS IT! THANKS IN ADVANCE FOR ANYONES HELP I REALLY APPRECIATE IT

[Bruce Nunnally]

Please don't add a new topic to continue discussing this one. I merged your post into this thread. If you can't find this thread, search for 'stranded', or click on your name and that takes you to your profile where you can find topics you started.

[Bruce Nunnally]

Here is a scan of the wiring diagram for the Theft Deterrent pass-key II system:

[Cadillac Jim]

good monday morning to all! i have no idea why i eagerly awoke and ran to my pc to view this thread where i was sure to find more information than i could use and certainly at least one CORRECT answer but NO REPLIES has my a little miffed? why ? im positive in the huge pool of knowledge available here SOMEONE CAN TELL ME EXACTLY WHERE IS THE 50MHZ SIGNAL WIRE TO THE ECU LOCATED IN MY 1996 ELDORADO I HAVE MY BYPASS CONSTRUCTED BUT NEED TO KNOW IF THE SIGNAL IS GENERATED WITHIN THE BCM. THEN WHAT WIRE IS IT THAT I NEED TO SUPPLY THE 5OMHZ SIGNAL. ALL THE GUIDES PERTAINING TO THE VATS BYPASS SAY BYPASS BOX OUTPOUT WIRE GOES TO THE TDM. THAT HAS ONLY 3 WIRES ....WELL IF MY CAR IS GENERATING THE 50MHZ SIGNAL WITHIN THE BCM THEN WHAT WIRE IS IT! THANKS IN ADVANCE FOR ANYONES HELP I REALLY APPRECIATE IT

It's the 4th of July weekend, and today is the 4th of July. Everybody is "down the shore" as they say in NJ, visiting family, having family over, etc. About the only email I've seen since Friday is from bots and subscriptions. You're in Cancun; put a sign in the Caddy saying "Be right back [with Federales]" and hit the beach until tomorrow.

Bruce posed the ignition security circuit portion that enables the starter as I was preparing this post, so I'll refer to it. To answer your question, since there doesn't seem to be a separate TDM in the circuit, I don't think that there is a place you will find the signal that you are looking for. That "square wave" is probably a PWM signal that may or may not have variable pulse widths as part of the signal.

The purple (PPL) wires shown as Data Line Connector connections in the upper left of Bruce's diagram have PWM data signals on them; these are complex computer communication data signals that transmits digital data according to Class 2, a CAN digital format modified for a PWM format for faster, more robust communication than the standard CAN bus format. On an oscilloscope it looks like a jittery square wave by trying to spoof it with a square wave generator is unlikely to be detected as anything other than a data line failure by whatever is on the other end. These data lines are how the IPC communicates with the DIM,PCM, and PZM and you can't spoof these data lines with a square wave generator.

My 1997 FSM, pages 9D-2 and 9D-3, go through the theft deterrent behavior as seen with various faults. I'll summarize all of them.

In normal operation, the SECURITY light is on for about 5 seconds when you first turn the key ON as a bulb check, then it goes off, or it goes off when you start the car.

If the SECURITY light stays on when the engine starts, either the IPC has not been programmed (a new one not installed by the dealer) or there was a problem with the PASS-Key II system when the engine was last running. Either way, there is likely a problem with the IPM.

If the SECURITY light stays on the engine does not start (apparently your problem; try again and watch the SECURITY light to be sure), the pellet in the key is incorrect (or has a bad connection). Remove the key, clear any lint or dirt off the key and keyhole, wait three minutes, put the key back in and the car should start. If the IPC never sees a good pellet, the car won't start.

If the SECURITY light keeps flashing off and on and the engine does not start, the pellet is missing or shorted. The engine will never start with a shorted or missing resistor pellet.

There is another thing that you need to look at: the Park/Neutral Position Switch. In Bruce's figure, it is in series with the ignition switch Start contacts. If the SECURITY light comes on for about 5 seconds and goes off, but the car doesn't start when you turn the key to START, hold the key in START and gently rock the transmission shifter back and forth in the Neutral detent and see if you can get the engine to start. If so, you need to adjust the Park/Neutral Position Switch.

[cancuncaddy]

ok so the tdm has been incorporated in the 1996 eldorado into the BCM which is in the trunk area i suppose and if thats the case could someone tell me or show me WHICH WIRE SHOULD I PUT MY 50MHZ SQARE WAVE SIGNAL TO ENABLE THE INJECTORS AND EFFECTIVELY OVERIDE THE THEFT SYSTEM PROBLEM?by that i mean to say THE WIRE THAT FEEDS THE SIGNAL TO THE ECU WHICH ONE IS IT????

[cancuncaddy]

good monday morning to all! i have no idea why i eagerly awoke and ran to my pc to view this thread where i was sure to find more information than i could use and certainly at least one CORRECT answer but NO REPLIES has my a little miffed? why ? im positive in the huge pool of knowledge available here SOMEONE CAN TELL ME EXACTLY WHERE IS THE 50MHZ SIGNAL WIRE TO THE ECU LOCATED IN MY 1996 ELDORADO I HAVE MY BYPASS CONSTRUCTED BUT NEED TO KNOW IF THE SIGNAL IS GENERATED WITHIN THE BCM. THEN WHAT WIRE IS IT THAT I NEED TO SUPPLY THE 5OMHZ SIGNAL. ALL THE GUIDES PERTAINING TO THE VATS BYPASS SAY BYPASS BOX OUTPOUT WIRE GOES TO THE TDM. THAT HAS ONLY 3 WIRES ....WELL IF MY CAR IS GENERATING THE 50MHZ SIGNAL WITHIN THE BCM THEN WHAT WIRE IS IT! THANKS IN ADVANCE FOR ANYONES HELP I REALLY APPRECIATE IT

It's the 4th of July weekend, and today is the 4th of July. Everybody is "down the shore" as they say in NJ, visiting family, having family over, etc. About the only email I've seen since Friday is from bots and subscriptions. You're in Cancun; put a sign in the Caddy saying "Be right back [with Federales]" and hit the beach until tomorrow.

Bruce posed the ignition security circuit portion that enables the starter as I was preparing this post, so I'll refer to it. To answer your question, since there doesn't seem to be a separate TDM in the circuit, I don't think that there is a place you will find the signal that you are looking for. That "square wave" is probably a PWM signal that may or may not have variable pulse widths as part of the signal.

The purple (PPL) wires shown as Data Line Connector connections in the upper left of Bruce's diagram have PWM data signals on them; these are complex computer communication data signals that transmits digital data according to Class 2, a CAN digital format modified for a PWM format for faster, more robust communication than the standard CAN bus format. On an oscilloscope it looks like a jittery square wave by trying to spoof it with a square wave generator is unlikely to be detected as anything other than a data line failure by whatever is on the other end. These data lines are how the IPC communicates with the DIM,PCM, and PZM and you can't spoof these data lines with a square wave generator.

My 1997 FSM, pages 9D-2 and 9D-3, go through the theft deterrent behavior as seen with various faults. I'll summarize all of them.

In normal operation, the SECURITY light is on for about 5 seconds when you first turn the key ON as a bulb check, then it goes off, or it goes off when you start the car.

If the SECURITY light stays on when the engine starts, either the IPC has not been programmed (a new one not installed by the dealer) or there was a problem with the PASS-Key II system when the engine was last running. Either way, there is likely a problem with the IPM.

If the SECURITY light stays on the engine does not start (apparently your problem; try again and watch the SECURITY light to be sure), the pellet in the key is incorrect (or has a bad connection). Remove the key, clear any lint or dirt off the key and keyhole, wait three minutes, put the key back in and the car should start. If the IPC never sees a good pellet, the car won't start.

If the SECURITY light keeps flashing off and on and the engine does not start, the pellet is missing or shorted. The engine will never start with a shorted or missing resistor pellet.

There is another thing that you need to look at: the Park/Neutral Position Switch. In Bruce's figure, it is in series with the ignition switch Start contacts. If the SECURITY light comes on for about 5 seconds and goes off, but the car doesn't start when you turn the key to START, hold the key in START and gently rock the transmission shifter back and forth in the Neutral detent and see if you can get the engine to start. If so, you need to adjust the Park/Neutral Position Switch.

[cancuncaddy]

JIM THANKS SO MUCH FOR ALL YOURE TIME AND EFFORT I REALLY APPRECIATE IT! OK HERES WHERE WE ARE .WHEN I TRY TO START THE CAR THE SHIFTER POSITION LIGHTS FLASH ON AND OFF THE CAR FIRES RIGHT UP.....AND RUNS FOR 3 SECONDS .....MESSAGE ON DASHBOARD STARTING DISABLED DUE TO THEFT SYSTEM PROBLEM .SINCE THIS STARTED I HAVENT BEEN ABLE TO PULL ANY CODES! IT WONT GO INTO DIAGNOSTIC MODE BY PUSHING OFF AND WARMER!!!I THINK A PRECURSOR OF THIS PROBLEM WAS 5 DAYS OF INCESSANT RAIN. WITH THE ACCOMPANYING STANDING WATER IN THE STREETS WHICH CAN BE REALLY DEEP HERE IN CANCUN .IF I CAN GET THE CAR HOME I CAN TAKE THE TIME AND DO TEDIOUS CHECKS OF EVERY CONNECTOR BECAUSE IT SEEMS TO ME TO BE THAT TYPE OF PROBLEM. AS FOR THE KEY PELLET ....I CIRCUMVENTED THAT PROBLEM MANY MONTHS AGO BY EMULATING THE RESISTANCE WHICH WORKED FLAWLESSLY...I DONT THINK THAT IS THE PROBLEM BECOUSE IF I DISCONNECT THE RESISTOR THERE APPEARS A TOTALLY DIFFERENT MESSAGE AND THE STARTER WONT ENABLE!!!!ALL THOSE POSTINGS ON PASSKEY BYPASS SYSTEMS SAY THAT ALL YOU HAVE TO DO IS EMULATE THE 50MHZ PULSED SQARE WAVE THAT THE BCM SENDS TO THE ECU I FOLLOWED INTSRUCTIONS AS TO HOW TO BUILD THE SIGNAL GENERATOR WHICH APPARENTLY ARE INSTALLED ON HUNDREDS IF NOT THOUSANDS OF g.m CARS NOW I HAVE THE GENERATOR BUT AM HAVING DIFFICULTY IN FIGURING OUT WHERE TO SPLICE IT IN!!! MY QUESTION IS THIS........IF INDEED THESE BYPASS SYSTEMS WORK THEN WHERE DO I PUT THE SIGNAL WIRE TO SUPPLY THE ECU WITH THE INFORMATION IT NEEDS TO LET MY CAR RUN?????????????

[Cadillac Jim]

The security system is distributed between the IPM, which measures the key pellet resistance, the PCM, which enables the injectors and counts the three minutes, and the PZM, which monitors all the door locks and the trunk tamper switch. They communicate over the car's network in a Class 2 data bus. I'm not aware of any dedicated data line from the PZM (which is the GM term for the body control module) to the PCM, and I think that the data it puts on the Class 2 bus goes to the IPM, where, apparently, the decisions are made for the PASS-Key II system.

From the diagrams in the 1997 FSM (page 8A-1233-0 is the one Bruce put up, 8A-133-1 and -2 show the BCM connections) I don't see where you could disconnect something and put in a square wave generator without making the car inoperative. Something like that will simply cause a Class 2 data line to shut down and throw a network code from whatever module the square wave was trying to spoof. It could blow the module.

My car is getting on in years, too, and I also see what I call "car wash codes" that show up after a car wash but go away by the next day and don't come back. If your car sits for a day and dries out, the problems should go away. My mechanic and I will re-seal the wiring harness next week. He's ordering the silicone gel with applicator and will disconnect all the sealed connectors from under the car, check and clean them and renew their silicone sealant, and reassemble them.

I would go back to where you got the instructions for using the square wave generator and ask them where it goes on your car, specifically. We can help you fix things here but apparently no one that has used the square wave generator approach on a Cadillac has seen your thread. 50 MHz sounds far too high a frequency for anything on a car data line. Are you sure that it's not 50 kHz? Perhaps if you gave us a link to the web page that recommends the square wave generator we might be able to help you figure out what they are thinking.

[cancuncaddy]

BY THE WAY I WISH HAVING MY CAR TOWED TO THE DEALERSHIP WAS AN OPTION BUT INTERESTINGLY ENOUGH OUR CANCUN CADILLAC DEALER ( WHERE THE CAR WAS PURCHASED BRAND NEW IN 1997) SERVICE MANAGER INFORMED ME THAT THEY ARENT AUTHORIZED TO DIAGNOSE AND OR REPAIR THOSE CARS!! HAVE YOU EVER HEARD OF SUCH A THING? THE WATER PUMP FAILED LAST YEAR AND I TOOK IT THERE LEAKING AND WAS TOLD THEY DONT HAVE THE SPECIAL TOOL TO REMOVE THE WATER PUMP SO I MADE ONE MYSELF OUT OF SOME THICKWALL TUBING AND HOURS WITH A DIE GRINDER! BUT I DO HAVE THE OTHER OPTION ( THE NOTE FOR THE FEDERALES!!!) MAYBE WHEN I GET BACK FROM THE BEACH THE GENIE WILL HAVE APPEARED DRIVEN THE MADNESS OUT OF MY THEFT SYSTEM!! THANKS FOR THE ADVICE ..THE BEACH IS A GREAT IDEA!