I have been going through all the previous posts regarding updating my car to LEDs. It's very confusing as there are many different options, CAN Bus LEDs, Resister LEDs, Plain LEDs, and LEDs with external resisters. I can't stand driving a car with a warning light on the dash. So my goal is to update my car with LEDs and not have a bulb warning light. I will explain the different type of LEDs and what's best to use. Since the LED technology is changing rapidly, it's time for a update to the most recent tech. But first here is a list of what others have shared on the forum.

LED, and HID Lamp Solutions 2008

Error Free LED Lights 2013

NEW LED Guide 2015

Eyebrow LED Running Lights 2018

License Plate LED Replacements

The Crossfire Lighting Circuit
The main circuit is the Illumination Control Module (ICM). This is a module that turns on or off each lamp based on inputs. The ICM has circuity to detect if a bulb is not working. This is done by measuring the current and resistance of each bulb. The Here is a picture of the module with the inputs.


Here is a picture of the ICM controlling the marker lights

Bad Bulb Circuit
The ICM is capable of detecting a bad bulb. In the old days, the user would turn on the headlights and power from that switch went directly to the headlights. The ICM works much differently, now the user turns on the headlights, a signal from the switch goes to the ICM. Inside the ICM, a relay or a transistor circuit powers on the light. As part of that circuit there is feedback to measure the current flow. The bulb is basically a resistor that throws out light. If the fuse or the bulb is bad, the current will not flow. The ICM can detect this and show a bad bulb indication.

LED Lights
A LED (Light emitting Diode) is a specialized semiconductor that emits light. Diodes have no resistance when on or infinite resistance when off. That's the simple explanation here is the more accurate explanation: diode is expected to offer zero resistance when forward biased and infinite resistance when reverse biased. The voltage must exceed minimum threshold voltage level for a diode to turn on and polarity does matter unlike a regular light bulb. Since the resistance of the LED is so low when on, the circuit in the ICM is not calibrated for the LED. It was calibrated for the regular light bulb.

What is a CAN Bus LED?
CAN bus is the communication bus that sends messages between the different modules. Much like your home network, the messages send information except it's related to the operation of the car. The Crossfire does not have a Illumination Control Module (ICM) that is controlled by the CAN bus. The ICM in the Crossfire has individual control wires for the inputs. A CAN bus LED is referring to a LED that has a resister wire in parallel or series. The purpose of this resister is to make the bulb detection circuit function properly. Newer cars will have ICM that are on the CAN bus.

Here is a circuit a CAN Bus LED with a load resistor.


Here is a CAN Bus LED Light Bulb showing the load resistor.

As I continue my research I will be adding to this thread.