Lexus ES: Left Low Beam Fan Malfunction (B243D,B243E)
DESCRIPTION
The headlight ECU sub-assembly operates the low beam fan to cool the headlight LED unit in order to prevent the headlight LED unit from overheating.
Illuminates the low beam headlights and continuously operates the low beam fan.
The headlight ECU sub-assembly monitors the pulse signals from the FANP terminal when the low beam fans are operating.
HINT:
If B243D or B243E is output, the headlight ECU sub-assembly performs low beam headlight dimming control.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area | DTC Output from |
|---|---|---|---|---|
| B243D | Left Low Beam Fan Malfunction |
|
| AFS |
| B243E | Right Low Beam Fan Malfunction |
|
| AFS (Sub) |
WIRING DIAGRAM
CAUTION / NOTICE / HINT
NOTICE:
-
If the headlight ECU sub-assembly LH has been replaced, it is necessary to synchronize the vehicle information and initialize the headlight ECU sub-assembly LH.
Click here
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- When replacing the headlight ECU sub-assembly LH, always replace it with a new one. If a headlight ECU sub-assembly LH which was installed to another vehicle is used, the information stored in it will not match the information from the vehicle and a DTC may be stored.
PROCEDURE
| 1. | CLEAR DTC |
(a) Connect the Techstream to the DLC3.
(b) Turn the engine switch on (IG).
(c) Turn the Techstream on.
(d) Enter the following menus: Body Electrical / AFS or AFS (Sub) / Trouble Codes.
(e) Clear the DTCs.
Body Electrical > AFS > Clear DTCs Body Electrical > AFS (Sub) > Clear DTCs
|
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| 2. | CHECK FOR DTC |
(a) Connect the Techstream to the DLC3.
(b) Turn the engine switch on (IG).
(c) Operate the light control switch to turn on the low beam headlights and wait 120 seconds or more.
(d) Turn the Techstream on.
(e) Enter the following menus: Body Electrical / AFS or AFS (Sub) / Trouble Codes.
(f) Check for DTCs.
Body Electrical > AFS > Trouble Codes Body Electrical > AFS (Sub) > Trouble CodesOK:
DTC B243D and B243E are not output.
| Result | Proceed to |
|---|---|
| OK | A |
| NG (DTC B243D is output) | B |
| NG (DTC B243E is output) | C |
| A | .gif) | USE SIMULATION METHOD TO CHECK |
| C | | GO TO STEP 6 |
|
| 3. | CHECK HEADLIGHT UNIT ASSEMBLY LH |
(a) Interchange the headlight unit assembly LH with RH and connect the connectors.
Click here
|
| 4. | CLEAR DTC |
(a) Connect the Techstream to the DLC3.
(b) Turn the engine switch on (IG).
(c) Turn the Techstream on.
(d) Enter the following menus: Body Electrical / AFS or AFS (Sub) / Trouble Codes.
(e) Clear the DTCs.
Body Electrical > AFS > Clear DTCs Body Electrical > AFS (Sub) > Clear DTCs
|
| 5. | CHECK FOR DTC |
(a) Connect the Techstream to the DLC3.
(b) Turn the engine switch on (IG).
(c) Operate the light control switch to turn on the low beam headlights and wait 120 seconds or more.
(d) Turn the Techstream on.
(e) Enter the following menus: Body Electrical / AFS or AFS (Sub) / Trouble Codes.
(f) Check for DTCs.
Body Electrical > AFS > Trouble Codes Body Electrical > AFS (Sub) > Trouble Codes| Result | Proceed to |
|---|---|
| DTC B243D is output | A |
| DTC B243E is output | B |
| A | | REPLACE HEADLIGHT ECU SUB-ASSEMBLY LH |
| B | | REPLACE HEADLIGHT UNIT ASSEMBLY LH |
| 6. | CHECK HEADLIGHT UNIT ASSEMBLY RH |
(a) Interchange the headlight unit assembly RH with LH and connect the connectors.
Click here
|
| 7. | CLEAR DTC |
(a) Connect the Techstream to the DLC3.
(b) Turn the engine switch on (IG).
(c) Turn the Techstream on.
(d) Enter the following menus: Body Electrical / AFS or AFS (Sub) / Trouble Codes.
(e) Clear the DTCs.
Body Electrical > AFS > Clear DTCs Body Electrical > AFS (Sub) > Clear DTCs
|
| 8. | CHECK FOR DTC |
(a) Connect the Techstream to the DLC3.
(b) Turn the engine switch on (IG).
(c) Operate the light control switch to turn on the low beam headlights and wait 120 seconds or more.
(d) Turn the Techstream on.
(e) Enter the following menus: Body Electrical / AFS or AFS (Sub) / Trouble Codes.
(f) Check for DTCs.
Body Electrical > AFS > Trouble Codes Body Electrical > AFS (Sub) > Trouble Codes| Result | Proceed to |
|---|---|
| DTC B243E is output | A |
| DTC B243D is output | B |
| A | | REPLACE HEADLIGHT ECU SUB-ASSEMBLY RH |
| B | | REPLACE HEADLIGHT UNIT ASSEMBLY RH |
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