Toyota Tundra Service Manual: LED Headlight LH Circuit Malfunction (B2430,B2431)

Toyota Tundra Service Manual / Vehicle Interior / Lighting / Lighting System / LED Headlight LH Circuit Malfunction (B2430,B2431)

DESCRIPTION

The illumination of the low beam headlights is controlled by the main body ECU (multiplex network body ECU). When the headlights are turned on, the main body ECU (multiplex network body ECU) receives a signal from the headlight assembly and detects the illumination condition of the low beam headlights.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

B2430

LED Headlight LH Circuit Malfunction

LED headlight LH circuit malfunction
  • Headlight assembly LH
  • Main body ECU (multiplex network body ECU)
  • Driver side junction block assembly
  • Harness or connector

B2431

LED Headlight RH Circuit Malfunction

LED headlight RH circuit malfunction
  • Headlight assembly RH
  • Main body ECU (multiplex network body ECU)
  • Driver side junction block assembly
  • Harness or connector

HINT:

DTC B2430 and B2431 are not output if 20 seconds have not elapsed since the ignition switch was turned on.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

Inspect the fuses for circuits related to this system before performing the following procedure.

PROCEDURE

1.

CHECK FOR DTC

(a) Clear the DTCs.

Click here

(b) Check for DTCs.

Click here

OK:

DTC B2430 and B2431 are not output.

Result

Proceed to

OK

A

NG (DTC B2430 and B2431 are output)

B

NG (DTC B2430 is output)

C

NG (DTC B2431 is output)

D
A

USE SIMULATION METHOD TO CHECK

C

GO TO STEP 6

D

GO TO STEP 9

B

2.

INSPECT HEADLIGHT RELAY (H-LP LO)

(a) Remove the headlight relay (H-LP LO) from the engine room relay block and junction block.

(b) Inspect the headlight relay (H-LP LO).

Click here

NG

REPLACE HEADLIGHT RELAY (H-LP LO)
OK

3.

CHECK HARNESS AND CONNECTOR (HEADLIGHT RELAY [H-LP LO] - BATTERY)

(a) Remove the headlight relay (H-LP LO) from the engine room relay block and junction block.

*a

Front view of wire harness connector

(to Headlight Relay [H-LP LO])

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

Headlight relay (H-LP LO) terminal 1 - Body ground

Always

11 to 14 V

Headlight relay (H-LP LO) terminal 3 - Body ground

Always

11 to 14 V
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

4.

CHECK HARNESS AND CONNECTOR (HEADLIGHT RELAY [H-LP LO] - DRIVER SIDE JUNCTION BLOCK ASSEMBLY AND HEADLIGHT ASSEMBLY)

(a) Remove the headlight relay (H-LP LO) from the engine room relay block and junction block.

(b) Disconnect the 3H driver side junction block assembly connector.

(c) Disconnect the A59 headlight assembly LH connector.

(d) Disconnect the A58 headlight assembly RH connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

Headlight relay (H-LP LO) terminal 2 - 3H-31

Always

Below 1 Ω

Headlight relay (H-LP LO) terminal 5 - A59-2 (LO)

Always

Below 1 Ω

Headlight relay (H-LP LO) terminal 2 or 3H-31 - Body ground

Always

10 kΩ or higher

Headlight relay (H-LP LO) terminal 5 or A59-2 (LO) - Body ground

Always

10 kΩ or higher
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

5.

CHECK DRIVER SIDE JUNCTION BLOCK ASSEMBLY

(a) Remove the driver side junction block assembly.

Click here

*a

Component without harness connected

(Driver Side Junction Block Assembly)

(b) Remove the main body ECU (multiplex network body ECU) from the driver side junction block assembly.

Click here

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

3H-31 - A-15 (HRLY)

Always

Below 1 Ω
OK

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

NG

REPLACE DRIVER SIDE JUNCTION BLOCK ASSEMBLY

6.

CHECK HARNESS AND CONNECTOR (HEADLIGHT RELAY [H-LP LO] - HEADLIGHT ASSEMBLY LH)

(a) Remove the headlight relay (H-LP LO) from the engine room relay block and junction block.

(b) Disconnect the A59 headlight assembly LH connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

Headlight relay (H-LP LO) terminal 5 - A59-2 (LO)

Always

Below 1 Ω
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

7.

CHECK HARNESS AND CONNECTOR (HEADLIGHT ASSEMBLY LH - MAIN BODY ECU [MULTIPLEX NETWORK BODY ECU] AND BODY GROUND)

(a) Disconnect the A59 headlight assembly LH connector.

(b) Disconnect the J165 main body ECU (multiplex network body ECU) connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

A59-3 (S) - J165-16 (LLEW)

Always

Below 1 Ω

A59-4 (E) - Body ground

Always

Below 1 Ω

A59-3 (S) or J165-16 (LLEW) - Body ground

Always

10 kΩ or higher
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

8.

CHECK HEADLIGHT ASSEMBLY LH

(a) Temporarily replace the headlight assembly LH with a new or normally functioning one.

Click here

(b) Clear the DTCs.

Click here

(c) Check for DTCs.

Click here

OK:

DTC B2430 is not output.

OK

END (HEADLIGHT ASSEMBLY LH WAS DEFECTIVE)
NG

MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

9.

CHECK HARNESS AND CONNECTOR (HEADLIGHT RELAY [H-LP LO] - HEADLIGHT ASSEMBLY RH)

(a) Remove the headlight relay (H-LP LO) from the engine room relay block and junction block.

(b) Disconnect the A58 headlight assembly RH connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

Headlight relay (H-LP LO) terminal 5 - A58-2 (LO)

Always

Below 1 Ω
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

10.

CHECK HARNESS AND CONNECTOR (HEADLIGHT ASSEMBLY RH - MAIN BODY ECU [MULTIPLEX NETWORK BODY ECU] AND BODY GROUND)

(a) Disconnect the A58 headlight assembly RH connector.

(b) Disconnect the J165 main body ECU (multiplex network body ECU) connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

A58-3 (S) - J165-3 (RLEW)

Always

Below 1 Ω

A58-4 (E) - Body ground

Always

Below 1 Ω

A58-3 (S) or J165-3 (RLEW) - Body ground

Always

10 kΩ or higher
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

11.

CHECK HEADLIGHT ASSEMBLY RH

(a) Temporarily replace the headlight assembly RH with a new or normally functioning one.

Click here

(b) Clear the DTCs.

Click here

(c) Check for DTCs.

Click here

OK:

DTC B2431 is not output.

OK

END (HEADLIGHT ASSEMBLY RH WAS DEFECTIVE)
NG

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