Technically, a few situations could cause this problem but below is by far the most common causes:
Even if this situation occurs after the system has been installed in the vehicle for awhile and previously worked fine or if this is happening during a new install test, it is commonly caused by one of the remote starter's ignition activation output wires; On a new install it can be that either a 2nd ignition wire in the vehicle needs to be powered up at the same time as the vehicle's 1st (or main/true ignition) wire or if a 2nd ignition wire was connected to during installation, the output timing of the 2nd ignition wire may not be providing the needed output at the same time as the remote starter's 1st ignition wire. We have even found some vehicle's that required the 2nd ignition output to be turned off during crank/start (basically the same as an accessory output wire but a required connection to start. Most accessory output connections are not required to get the vehicle to remote start, they are only needed for HVAC activation).
Now on a existing installation that was previousely working fine, the output timing would not change, so the first thing to check is the systems ignition outputs, check both for faulty connections to the vehicle's wiring and test the remote starter system's ignition output wires during remote start activation to confirm that the outputs are working properly. Other than this being the cause, we would have to get a little deeper into the situation which will be another post.
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