Originally Posted by
az3579
If I may make a recommendation, I would advise against white LEDs for turn signals simply for the fact that they would be incredibly blinding to other people at night. Also, I recommend red LED bulbs for any parts of the lights that have a red lense. This way, the color will remain true red and not the pinkish color you get from having white bulbs behind red lenses.
The CANBUS system utilizes a series of bulb checks to check for bulb functionality. Cold checking occurs when you first turn the ignition on. The LCM sends small pulses of electricity to the bulbs to verify that they are there and functioning. If it detects any bulbs that don't meet its parameters, it will trigger a bulb-out warning on your cluster.
Hot checks occur periodically while the car is in operation. Its purpose is the same, which is to notify you of failed bulbs.
These electricity pulses happen very quickly, and because our cars have incandescent bulbs from the factory, they will never actually illuminate when these checks occur due to the very long time it takes for the bulbs to warm up enough to illuminate the bulb. With LED bulbs, the response is immediate since they are instant on/off bulbs. What that means is that when the hot/cold checks are occurring, you'll see the LED bulbs flicker a few times as the pulses are being sent.
Coding the hot/cold checks to be disabled prevents the LED bulbs from flickering. What does that mean for you? Well, you'll lose the advance notice of a failed bulb, and instead will only get the bulb out notification when the bulb actually fails. In theory, you could start your car, drive down the street and go to use your turn signals, for example, only to find that one of them isn't working, at which point the bulb failure light will illuminate and the indicator will blink rapidly.
Since my LEDs have been working flawlessly for the few years I've had them and have not experienced a failure, I can't comment on how an actual failure presents itself. I have, however, tested this by pulling random bulbs with the car parked and then activating them to see how the instrument cluster displays a failure. So far, these tests have proved that the system still does its job and notifies of failures, just not with advance warning.
Hot/cold check coding can be done with NCS Expert. I don't know if PA Soft does it because I rarely ever use it for anything, but I'm sure it would have basic functionality such as that type of coding.
