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Discussion Starter #1
My background is electronics. (Cars, Home, Audio, Video, Security, etc)

Once I am complete I will post on this site the instructions.

I am in the process of installing an alarm system with remote start.
Car: 2007 Chrysler 300C
Alarm System: Scytek_ Astra 4000RS-2W-1
Transponder Bypass: Omega_DB-CHDL7P2

The transponder learns by storing the code on both car keys. This device also contains the codes for the following function to eliminate the need for relays and resistors to interface to the data bus. The device controls:
Door Lock control (Lock/unlock)
Factory alarm (Arm/disarm)
Trunk release
Horn Chirp
Entry status (Door pins, trunk pins)

To start the car with my key the following takes place. The ignition system reads a code from the ignition key. While cranking the car “START” position (activating starter) a 180ohm resistor is placed across a special port in the car. Once the car is started and the key is turned to “RUN” position the resistor value is changed to 610ohm.

To get the remote starter to work you must fool the car to think its being started by the ignition key. Here are the steps.
The alarm remote activates the transponder bypass to fool the ignition system. An external relay closes to activate the starter and at the same time it places a 180ohm resistor across the special port in the car. Once the car is started the relay opens back up. The alarm senses the car is running so it activates three other relays. The relays close. A) Ignition, B) Accessory/Heater/Blower, and C) places 610ohm resistor across the special port.

QUESTION: What happens when I get in the car while the car in running in remote start mode. Put my key in the ignition and turn my key to “RUN”. If I do this I will now be placing a 610 ohm resistor in parallel with the remote start 610 ohm resistor. The special port will now see resistor value of 305 ohms (610 in parallel with 610 equals 305)

5 Posts
Discussion Starter #2
problem, db chdl7p2, 2007 chrysler 300c

Vehicle: 2007 Chrysler 300c
Alarm System: Scytek_Astra 4000RS w/remote start
Transponder: Omega_DB-CHDL7P2
Things that work
The car starts and runs properly using the factory keys.
The car starts and runs properly using the Remote starter remote.
The transponder sends the car alarm a negative pulse when I open the doors….meaning the DB-CHDL7P2 is reading the car’s data line and telling the alarm the doors are open.
Here is the problem I am having.
The alarm remote do not lock unlock doors / open trunk /or deactivate the factory alarm. Reason: the transponder is not taking the signals from the car alarm and communicating it to the car’s data line.

If I activate the lock or unlock buttons on the alarm remote I can see the negative pulse going to the transponder’s lock pins 2 or unlock pin 3. If I select the trunk open button on the remote I can see the negative pulse going to the transponder pin 8.
I also ran a ground wire for 1 second across each pins (2, 3, and 8) to see if the transponder would lock, unlock door or open trunk. Nothing happened.
The transponder is connected up correctly because the remote starter works. I used the MUX system provided by the transponder to apply the correct resistor values. Plus pin 4 of the transponder sends the car alarm a negative pulse when I open the doors.
I tried to reset the Doorlock Interface by pressing the program buttons until I got Mode8 option2 “Complete reset of option and mode” . Still same problem.
Have anyone seen this problem before. What should I do next.
My wiring connections are below
Transponder wires connections:
1 to Coil
2 to Coil
1 Red IN to Car’s Ignition switch (PK/WT)
2 no connection
1 Brown IN to Alarm’s “Gnd when running” Blue/Orange
2 Green IN to Alarm’s Door Lock “lock out (-)” Green
3 Blue IN to Alarm’s Door Lock “unlock out (-)” Blue
4 Violet/White OUT to Alarm’s “Negative door input” Green
5 Violet DATA Car’s SKIM pins 6 “DATA” white/orange
6 Pink/White OUT to Car’s Ignition switch “2nd Starter/Ign” Violet/Brown
7 Pink IN to Car’s Ign SW “starter” pink/dk green and Alarm’s “Starter Out” Violet
8 Orange IN to Alarm’s “Trunk Release Out (-) Gray
9 Red IN to Car battery +12v
10 Black IN to Car chassis
Note a 1k ohm resistor is also connected between Pin 7 Pink the Pin 10 Black
All my connections are soldered.
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