ADAPTIVE HIGH BEAM SYSTEM, Diagnostic DTC:B2490, B2491

DESCRIPTION

The light control LED ECU receives adaptive high beam system control signals from the headlight ECU sub-assembly via LIN communication and operates the additional fan to cool the LED in order to prevent overheating of the additional LEDs.

When the low beam headlight is illuminated, it continuously operates the additional fan.

The light control LED ECU uses pulse signals from the FANP terminal to monitor additional fan rotation signals, and when it detects a malfunction, it sends a signal to the headlight ECU sub-assembly via LIN communication.

WIRING DIAGRAM

PROCEDURE

1. CHECK FOR DTC

   
   

   1. Clear the DTCs.

      Click here

      
      Body Electrical > AFS > Clear DTCs

   2. Turn the engine switch on (IG).

   3. Operate the light control switch to turn on the low beam headlights.

   4. Check for DTCs.

      Click here

      
      Body Electrical > AFS > Trouble Codes

      OK
      DTC B2490 or B2491 are not output.

      Result
      Result Proceed to OK A NG (DTC B2490 is output) B NG (DTC B2491 is output) C

   
   

   A

   USE SIMULATION METHOD TO CHECK Click here

   C

   INSPECT HEADLIGHT UNIT ASSEMBLY RH Click here

   B

2. INSPECT HEADLIGHT UNIT ASSEMBLY LH

   
   
   1. 

      *a	Component without harness connected (Light Control LED ECU LH)
      *b	Component without harness connected (Headlight Unit LH)

      Remove the headlight unit LH.

      Click here

   2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition G-13 - H-2 Always Below 1 Ω G-12 - H-12 Always Below 1 Ω G-2 - H-1 Always Below 1 Ω

      Result
      Proceed to OK NG

   
   

   NG

   REPLACE HEADLIGHT UNIT ASSEMBLY LH Click here

   OK

3. CHECK LIGHT CONTROL LED ECU LH

   
   
   1. 

      *a	Component without harness connected (Headlight Unit LH)

      Remove the headlight unit LH.

      Click here

   2. Reconnect the headlight ECU sub-assembly LH connectors.

   3. Reconnect the light control LED ECU LH connectors.

   4. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Condition Specified Condition H-2 - H-1 Low beam headlights illuminated 4.75 to 5.25 V H-12 - H-1

      Result
      Proceed to OK NG

   
   

   OK

   REPLACE HEADLIGHT UNIT LH Click here

   NG

   REPLACE LIGHT CONTROL LED ECU LH Click here

4. INSPECT HEADLIGHT UNIT ASSEMBLY RH

   
   
   1. 

      *a	Component without harness connected (Light Control LED ECU RH)
      *b	Component without harness connected (Headlight Unit RH)

      Remove the headlight unit RH.

      Click here

   2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition G-13 - H-10 Always Below 1 Ω G-12 - H-22 Always Below 1 Ω G-2 - H-11 Always Below 1 Ω

      Result
      Proceed to OK NG

   
   

   NG

   REPLACE HEADLIGHT UNIT ASSEMBLY RH Click here

   OK

5. CHECK LIGHT CONTROL LED ECU RH

   
   
   1. 

      *a	Component without harness connected (Headlight Unit RH)

      Remove the headlight unit RH.

      Click here

   2. Reconnect the headlight ECU sub-assembly RH connectors.

   3. Reconnect the light control LED ECU RH connectors.

   4. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Condition Specified Condition H-10 - H-11 Low beam headlights illuminated 4.75 to 5.25 V H-22 - H-11

      Result
      Proceed to OK NG

   
   

   OK

   REPLACE HEADLIGHT UNIT RH Click here

   NG

   REPLACE LIGHT CONTROL LED ECU LH Click here