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Electrical expert needed.

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Old 02-04-2007, 02:10 PM
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Electrical expert needed.

Okay, I had the door switches replaced and after a couple days my keyless unlock started setting off the horn again upon unlocking the doors. Three honks to let me know the alarm went off when I know it didn't. The dealer suggested I unhook the trailer brakes. Two days, about seven lock/unlock cycles and then... bam the three honks returned! Always late night or early morning and very annoying. Does anybody know what / where I should look next? Does this sound like a short or a resistance problem? This is the only thing I haven't been able to fix/repair/replace on this truck and its annoying me and my neighbors. Any comments welcome. And yes, I have considered unhooking the horns for good. I don't need them because I am ready to scream everytime this happens. Help!
Old 02-11-2007, 07:46 PM
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Kurtaing, I will give it a shot. First a little background on the Vehicle Theft Security System (VTSS). According to the shop manual the VTSS tamper alert will sound the horn three times upon disarming, if the alarm was triggered and has since timed out (about 15 minutes). You are getting the three beeps without the alarm going off. This tells me there is an electrical fault with the VTSS. I’m sure you have come to that conclusion also.

Digging a little deeper into the hardware tells me that the VTSS circuit is part of the Central Timer Module (CTM). This module is microprocessor based and controls the following:
Chime, Intermittent wipers, Chrysler Collision Detection (air bags), Door locks/Keyless entry, Courtesy lamps, Heated seats, Remote radio switch, and Vehicle alarm.
Dodge recommendation on troubleshooting the CTM warns about first disarming the air bags and using a scan tool.
Here is the quote.
“However, conventional diagnostic methods may not
prove conclusive in the diagnosis of the high-line/premium
CTM. In order to obtain conclusive testing of
the high-line/premium CTM, the Chrysler Collision
Detection (CCD) data bus network and all of the electronic
modules that provide inputs to or receive outputs
from the CTM must also be checked. The most
reliable, efficient, and accurate means to diagnose
the high-line/premium CTM, the CCD data bus network,
and the electronic modules that provide inputs
to or receive outputs from the high-line/premium
CTM requires the use of a DRBIII scan tool and the
appropriate diagnostic information. The DRBIII
scan tool can provide confirmation that the CCD data
bus network is functional, that all of the electronic
modules are sending and receiving the proper messages
over the CCD data bus, and that the CTM is
receiving the proper hard wired inputs and responding
with the proper hard wired outputs needed to
perform its many functions.”

From personal experience with troubleshooting electrical circuits, I can tell you that the most difficult problem comes from trying to find an intermittent problem. One like the 2 days between faults that you have experienced. The only suggestion I can make, if time and money allow, is to go back to the dealer and have them use the DRBIII scan tool. The other option is to replace the CTM but that may be cost prohibitive. I am a little surprised the dealer replaced the door switches in your truck. He should have been able to check them with the scan tool. Suggesting removing your trailer brakes to fix the problem seems like a shot in the dark. Maybe try someone else.

Wish I could have been more help but without a scanner it is going to be tough.
Old 02-11-2007, 08:03 PM
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my truck has started that little "trick" in the last 6 months or so. It's only done it maybe three times. I don't have the owners manual in front of me, but there is a certain light sequence on the security system that will flash if the alarm has been triggered so I've been walking up to the truck before I hit "unlock" to see if it has changed.

It's not a real common prob, or one that I'm all that familiar with, but I have the feeling I had better start researching a bit.
Old 02-11-2007, 11:05 PM
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Thanks for all the info bent valves. That's the most comprehensive explanation I have received since this started last summer. The local dealer is feeling quite ready to help after the door switch job ended up costing them a new door panel after they ruined my drivers side while trying to get it off and then came to find out the new switches didn't fix the problem. They have treated me very fairly since I started going there and the service manager seems truly concerned with my problem. I'm out $160 and some time. If its the CTM i get the feeling I'm looking at a lot more money? Thanks again, Kurt

Last edited by SIXSLUG; 02-11-2007 at 11:13 PM. Reason: more info
Old 02-12-2007, 01:15 PM
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I did not mean to cast aspersions on your dealer and technician. There are many great dealers with knowledgeable staff. They probably took the best first guess at the problem based on prior experiences. When you get this problem solved, please post the answer. It looks like it could help others and you have me curious.

J Body, that is an excellent idea to read the flashes. My 1998 truck does not offer that useful feature.
Old 02-12-2007, 10:46 PM
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Well at least he KNOWS that his door switches are not the problem. He's two parts ahead of me!! VTSS probs have been few and far between so I don't really know of a "common" issue on these trucks pertaining to this phenom. I'll have to hook up the DRB and play around a bit. It seems to me that there in a screen that will show "last trigger", but I may be thinking of a different model line.......I wish I only had one or two vehicles to consentrate on.



....well I just went out and monitored the overhead vtss light. It would flash about every two seconds. Hit unlock and HONK HONK HONK!! I did grab the owners manual and found that I must have dreamt that "light display" change that I mentioned above.....there again, maybe a different product line.
Old 02-12-2007, 10:53 PM
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....some informative reading. Anything that helps you in anyway will automatically put you on my "you owe me a beer list". Hope this sheds a little light on the system.



VEHICLE THEFT SECURITY SYSTEM
The Vehicle Theft Security System (VTSS) is an available factory-installed option on this model when it is also equipped with the high-line or premium Central Timer Module (CTM) . The VTSS is designed to provide perimeter protection against unauthorized use or tampering by monitoring the vehicle doors and the ignition system. If unauthorized vehicle use or tampering is detected, the system responds by pulsing the horn, flashing the headlamps, and preventing the engine from operating.

The VTSS includes the following major components, which are described in further detail elsewhere:


Central Timer Module - The high-line or premium Central Timer Module (CTM) is located under the driver side end of the instrument panel, inboard of the instrument panel steering column opening. The high-line or premium CTM contains a microprocessor and software that allow it to provide many electronic functions and features not available with base version of the CTM, including the VTSS. The CTM provides all of the proper VTSS features and outputs based upon the monitored inputs. The CTM circuitry monitors hard wired switch inputs, as well as message inputs received from other vehicle electronic modules over the Chrysler Collision Detection (CCD) data bus network.
Door Ajar Switch - A door ajar switch is located on the hinge pillar of each front door in the vehicle. These switches provide an input to the VTSS indicating whether the door is opened or closed.
Door Cylinder Lock Switch - A door cylinder lock switch is located on the back of each front door lock cylinder. This switch provides an input to the VTSS indicating whether the system should remain armed or be disarmed.
Horn Relay - The horn relay is located in the Power Distribution Center (PDC) in the engine compartment near the battery. The horn relay is normally activated by the horn switch to control the sounding of the vehicle horn or horns. However, it can also be activated by an output of the Central Timer Module (CTM) to provide an audible indication that unauthorized vehicle use or tampering has been detected.
Headlamp Relay - The headlamp relay (also known as the security relay) is located in the Power Distribution Center (PDC) in the engine compartment near the battery. The headlamp relay is normally activated by the Central Timer Module (CTM) based upon inputs from the Remote Keyless Entry (RKE) panic mode feature. However, it can also be activated by an output of the CTM to flash the headlamp low beams to provide a highly visible indication that unauthorized vehicle use or tampering has been detected.
VTSS Indicator - A red Light Emitting Diode (LED) located on the lower surface of the overhead console near the windshield is illuminated by an output of the Central Timer Module (CTM) to indicate the status of the VTSS. This LED is integral to the electronic circuit board for the Compass Mini-Trip Computer (CMTC) .
The engine no-run feature of the VTSS relies upon communication between the high-line or premium CTM and the Powertrain Control Module (PCM) over the Chrysler Collision Detection (CCD) data bus network.

Hard wired circuitry connects many of the VTSS components to each other through the electrical system of the vehicle. These hard wired circuits are integral to several wire harnesses, which are routed throughout the vehicle and retained by many different methods. These circuits may be connected to each other, to the vehicle electrical system and to the VTSS components through the use of a combination of soldered splices, splice block connectors, and many different types of wire harness terminal connectors and insulators.

A Central Timer Module (CTM) is used on this model to control and integrate many of the electronic functions and features included in the Vehicle Theft Security System (VTSS). In the VTSS, the CTM receives inputs indicating the status of the door ajar switches, the door cylinder lock switch, and the ignition switch. The programming in the CTM allows it to process the information from all of these inputs and send control outputs to energize or de-energize the horn relay, the headlamp relay, and the VTSS indicator. The control of these inputs and outputs are what constitute all of the features of the VTSS. Following is information on the operation of each of the VTSS features. Refer to the owner's manual in the vehicle glove box for more information on the features, use and operation of the VTSS.

Enabling
The high-line or premium version of the CTM must have the VTSS function electronically enabled in order for the VTSS to perform as designed. The logic in the CTM keeps its VTSS function dormant until it is enabled using a DRB III scan tool. The VTSS function of the high-line or premium CTM is enabled on vehicles equipped with the VTSS option at the factory, but a service replacement CTM must be VTSS-enabled by the dealer using a DRB III scan tool. Refer to the appropriate diagnostic information.

The VTSS engine no-run feature is disabled when it is shipped from the factory. This is done by programming within the Powertrain Control Module (PCM). The logic in the PCM prevents the VTSS engine no-run feature from arming until the engine start counter within the PCM sees twenty engine starts. The VTSS no-run feature must be enabled by the dealer when the vehicle is received from the assembly plant. Once the VTSS engine no-run feature has been enabled, it cannot be disabled unless the PCM is replaced with a new unit. The same VTSS engine no-run feature enable logic will apply anytime the PCM is replaced with a new unit.

Arming
Passive arming of the VTSS occurs when the vehicle is exited with the key removed from the ignition switch, the headlamps are turned OFF, and the doors are locked while they are open using the power lock switch, or locked after they are closed by turning either front door lock cylinder to the lock position using the key. The power lock switch will not function if the key is in the ignition switch or the head- lamps are turned on with the driver side front door open. The VTSS will not arm if the doors are locked using the mechanical lock button. Active arming of the VTSS occurs when the "Lock" button on the Remote Keyless Entry (RKE) transmitter is depressed to lock the vehicle. For active arming to occur, the doors must be closed and the ignition switch must be in the OFF position when the RKE transmitter "Lock" button is depressed. However, once the VTSS arming process has been completed, the ignition switch can be turned to the Accessory position without triggering the alarm.

Once the VTSS begins passive or active arming, the security indicator lamp in the overhead console will flash rapidly for about fifteen seconds. This indicates that the VTSS arming is in progress. Turning a key in the ignition switch, opening a door, or unlocking a door by any means during the fifteen second arming process will cause the VTSS indicator to stop flashing and the arming process to abort. Once the fifteen second arming function is successfully completed, the indicator will flash at a slower rate, indicating that the VTSS is armed.

Disarming
Passive disarming of the VTSS occurs when the vehicle is unlocked using the key to unlock either front door. Active disarming of the VTSS occurs when the vehicle is unlocked by depressing the "Unlock" button of the RKE transmitter. Once the alarm has been activated (horn pulsing, headlamps flashing, and the engine no-run feature), either disarming method will also deactivate the alarm. Depressing the "Panic" button on the RKE transmitter will not disarm the VTSS.

Power-UP Mode
When the armed VTSS senses that the battery has been disconnected and reconnected, it enters its power-up mode. In the power-up mode the alarm system remains armed following a battery failure or disconnect. If the VTSS was armed prior to a battery disconnect or failure, the technician or vehicle operator will have to actively or passively disarm the alarm system after the battery is reconnected. The power-up mode will also apply if the battery goes dead while the system is armed, and battery jump-starting is attempted. The engine no-run feature will prevent the engine from starting until the alarm system has been actively or passively disarmed. The VTSS will be armed until the technician or vehicle operator has actively or passively disarmed the alarm system. If the VTSS is in the disarmed mode prior to a battery disconnect or failure, it will remain disarmed after the battery is reconnected or replaced, or if jump- starting is attempted.

Tamper Alert
The VTSS tamper alert feature will sound the horn three times upon disarming, if the alarm was triggered and has since timed-out (about 15 minutes ). This feature alerts the vehicle operator that the VTSS alarm was activated while the vehicle was unattended.

VTSS INDICATOR
The Vehicle Theft Security System (VTSS) indicator consists of a red Light-Emitting Diode (LED) located on the electronic circuit board of the Compass Mini-Trip Computer (CMTC) within the overhead console. The LED extends through a hole in the CMTC lens located near the forward end of the overhead console housing near the windshield.

The VTSS indicator cannot be adjusted or repaired and, if faulty or damaged, the entire CMTC unit must be replaced. (Refer to OVERHEAD CONSOLE/COMPASS/MINI-TRIP COMPUTER - DESCRIPTION).

The Vehicle Theft Security System (VTSS) indicator gives a visible indication of the VTSS arming status. One side of Light-Emitting Diode (LED) in the VTSS indicator is connected to battery current through a fused B(+) circuit and a fuse in the Junction Block (JB) , so the indicator remains functional regardless of the ignition switch position. The other side of the LED is hard wired to the Central Timer Module (CTM), which controls the operation of the VTSS indicator by pulling this side of the LED circuit to ground. When the VTSS arming is in progress, the CTM will flash the LED rapidly ON and OFF for about fifteen seconds . When the VTSS has been successfully armed, the CTM will flash the LED ON and OFF continually at a much slower rate until the VTSS has been disarmed. The VTSS indicator can be diagnosed using conventional diagnostic tools and methods.

RKE/VTSS
Only the highline and premium CTM'S have provision for RKE and VTSS. The VTSS system monitors the jamb swathes and ignition switch to detect unauthorized entry. One the system is armed, any one of these inputs an cause the system to initiate an alarm. When in alarm, the low beam headlamps and horn will pulse for about 3 minutes . If the engine is started, it will immediately stall. If the triggering condition remains, the headlamps will pulse for an additional 15 minutes , but the engine cannot be made to run until the system is disarmed. If the triggering condition is restored, the system will reset and return to the armed state.If the system has rearmed itself, it will sound three horn chirps as a tamper alert when the system is disarmed. The CTM will store the last four causes of a VTSS alarm. The causes an be retrieved by the DRB III.

The VTSS system an be disarmed by unlocking the doors with the RKE transmitter or with a door key at either door.

A VTSS indicator in the overhead console will blink rapidly during system arming, slowly when armed and remain ON to indicate a system fault.

The RKE system is programmed by the DRB III. The system will store up to four key fob codes. Using the DRB III, it is possible to program one code without deleting the others. All stored key fob codes an be erased and reprogrammed to prevent unauthorized entry with lost or stolen key fobs.
Old 02-12-2007, 11:26 PM
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Old 02-12-2007, 11:29 PM
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....which brings up another item......the door ajar switches. I have a "hunch" that this may a problem area. Temp change can have an effect on them. I popped mine out and sprayed them with brake clean while working them in/out and reinstalled them. Guess I'll see if it works.......however long that may be.
Old 02-14-2007, 10:03 PM
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Hey Dave (aka bent valve) Thanks again for the leads, no offense taken re my dealership guy. J Body- that was a poopload of typing and a real informative look into this problem I have been having. Mine goes off hot/cold/wet/dry/damp/dark/light, whenever. There's no definite pattern that I can detect. Again, Thanks for spending some time at the keyboard on this one! Kurt
Old 02-18-2007, 10:00 PM
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Hey J Body, are the door ajar switches the buttons at the front middle of each door? If so I already tried that and it didn't help. Are there switches on the quad doors at the bottom? It's going back in Tues for a DRB scan. Maybe they'll find something. BTW, my overhead red light flashes about every 2 sec. also and I watch it for any message. It just goes off when I unlock the doors,honk or no honk. Thanks, Kurt
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