Led Headlight Problem

Did you have the CECU programmed for LED lights? Probably sensing low current becasue it's programmed for OEM bulbs. You need Paccar ESA and it's just a quick parameter change.

 

Probably. I am not sure how CECU reacts to input voltage as far as what the acceptable amp range is, but you have 1.5-2 volts more with the truck running, which would change amperage through the bulb. That range would change a lot more for an incandescent lamp than it would for an LED, which are typically cut down to 5 volts in the LED.

Some LED kits have resistors built in that don't require programming, some do. The instructions should tell you, but I wouldn't be surprised if they don't say on cheaper kits. I do know that in the parameters, lights have an LED or Incandescent option, which changes the acceptable amperage high/low to match the bulbs. If it goes high or low, it sets a fault. A flashing high beam indicator means a headlight fault on your truck and I'm guessing that if you pull the faults, you'll have one for low current.

 

Hope you don't do a lot of snow storm driving....The truck light ones for the W9/T8 are unusable in the snow .

My low beams are 3 season only I guess

 

Many LED only work at 12 volts and higher. LED's in some internationals have a hard time with DRL because they run at a lower voltage, usually around 8 or so to produce the dimmed light. LEDs simply won't function at 8 volts, or if they do they will flicker.

 

I got these...