771xv & GMDL-BP won’t start when armed.
Printed From: the12volt.com
Forum Name: Car Security and Convenience
Forum Discription: Car Alarms, Keyless Entries, Remote Starters, Immobilizer Bypasses, Sensors, Door Locks, Window Modules, Heated Mirrors, Heated Seats, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=79618
Printed Date: May 16, 2025 at 8:27 AM
Topic: 771xv & GMDL-BP won’t start when armed.
Posted By: mobilevt
Subject: 771xv & GMDL-BP won’t start when armed.
Date Posted: June 25, 2006 at 7:15 PM
I have a 2003 Chevy Silverado 1500HD with Bose system. It has everything but the memory seats. I am installing the 771XV alarm with the GMDL-BP set at #4 for the Silverado. I have everything set up and before doing the final placement of the components & re-installing the trim, covers, etc. I tested everything. I was able to arm & disarm and the doors senses correctly. When doing the remote start feature, I was able to start the car in the unarmed state with no problems however, in the armed state, it will only crank and fails to turn over. This will happen 3 times before quitting the process. I have tried to change the sense from tach to voltage to see if it helped but it didn't. I was going over the installation manual to see if I missed a critical installation step and searched for any related topics with that issue. I did find references to the flip-flop state of the door lock & unlock which I installed the proper relays which helped. The Alarm & GMDL-BP gets the power from the databus power & ground wires as suggested by someone in the forum to eliminate any ground loops between the two units. My questions, Am I missing something? Is there something to the vehicle that I must change the state for it to allow the alarm to start the vehicle? Also after deactivating the remote start in the unarmed state, the alarm will self-arm. I'd like for the system to be entirely passive and only arm & disarm under my discretion. Any assistance is appreciated! Sean
Replies:
Posted By: Chris Luongo
Date Posted: June 25, 2006 at 11:49 PM
The only guess I could think of is that somehow the GM-DLBP is not getting activated when the Viper system is armed.........but I am unable to think of any wiring mistake you could make, that would cause that to happen.
When you arm it and try to remote start, look at the orange "padlock" picture in the dash.......does it come on solid and then go out, or is it flashing?
If it is flashing, it's the PASSLock II system in the truck that's preventing it from starting---time to consider some wiring issues with the GM-DLBP.
If the light behaves normally, PASSLock II is okay.
The GM-DLBP's brown wire is supposed to see a ground whenever the remote start is on............this should be connected to the "status" wire of the Viper, which I believe is blue/black.
At any rate, put a tester to that brown wire.........armed or disarmed.........it's supposed to be getting a ground starting from the VERY moment you activate the remote start, and STAY grounded until the remote start is turned off.
Posted By: mobilevt
Date Posted: June 26, 2006 at 3:19 AM
Chris, Looked at the installation manual. Must be the blue/white which does exactly as you said the circuit should do. You actually gave me quite some relief that I'm completely convinced that this is the solution! I appreciate it immensiously! One additional question if you don't mind me asking. I forgot to mention it earlier. The alarm is actually seeing the dome light thru the GMDL-BP and therefore thinking that there is an open door but goes to full arm because it sees the door closed after the domelight times out. It causes the "door still open" notification when arming. Should I get my connections at each door with isolating diodes at the BCM or? Currently, the pink wire from the GMDL-BP is connected to the grey/black wire on the black plug at the BCM direct and the pink/white is connected to the blue wire of the 771XV (neg door trigger input). Again, much appreciation for your knowledge! Sean
Posted By: Chris Luongo
Date Posted: June 26, 2006 at 2:26 PM
Is the truck a 2-door or 4-door?
If it's a 2-door, just disconnect the pink wire from the domelight altogether, and forget about it.
Here's why:
The two front doors each have a Door Module, which comminucate the door-open status to the BCM through the data wire.
The rear doors (if equipped), are not part of the databus system, and their doorlatch switches are wired directly to the BCM, just like any other car.
---The GM-DLBP will monitor the status of the two front doors through the databus, and the pink/white will put out a ground whenever either front door is open, regardless of the domelight being hooked up or not.
---The GM-DLBP is unable to monitor the rear doors on its own, and counts on the domelight to do that. (Note: if you disable the domelight using the dash-mounted switch, you lose the monitoring of the rear doors.)
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