Reported Problem: Remote Starter Cranks Car but won't Remote Start when Cold
This problem is regularly reported on a weekly basis soon as the mid-west and east coast receives it's first frost towards the beginning of the winter.
Most Common Cause: The remote starter system may have been installed using a "tachless" mode; This setting can range from voltage level detection or a pre-set crank/start output setting. This is where the system is programmed to either monitor the standing voltage of the vehicle and then compares that voltage reading to the voltage level after it cranks/starts and the alternator kicks in or the system is pre-set to crank/start at a predetermined time, respectively. So, when the vehicle is cold (usually at or below 32°F or 0°C) the system either doesn't detect a significant raise in voltage levels (usually >0.5V) or the pre-set output isn't long enough to get the vehicle to start. While these two settings work fine in warmer environments that rarely see frost (or none at all), it's possible these settings won't provide a dependable start in or during a colder climate.
Possible Fix: Connect and program the system's tachometer input. All remote starters have what is called a tachometer detection input wire. This is a hard-wired connection made directly to either the vehicle's tachometer wire, odd-colored fuel injector wire or a specific coil wire commonly found at the vehicle coil-pack on the engine. This is by far the best way to install any remote starter system regardless of the climate.
When the system is installed utilizing the system's tachometer input, the system directly monitors and detects the small amount of AC voltage that this wire in the vehicle shows while the vehicle is running. Then after this AC voltage level is programmed into the system, when the remote starter is activated and if this level isn't detected right away, the system will automatically crank the vehicle a little longer until this level is detected or it will shut down and automatically try to re-start the vehicle again (on some systems up to 3 times). This connection is strongly recommended on all Diesel engines and will provide a dependable remote start on any vehicle.