DTC B2430: LED Headlight LH Circuit Malfunction; DTC B2431: LED Headlight RH Circuit Malfunction [09/2014 - ]: Procedure

1. Clear the DTCs. Refer to DTC CHECK / CLEAR [09/2014 - ] .
2. Check for DTCs. Refer to DTC CHECK / CLEAR [09/2014 - ] .
   RESULT
   
   

   Result	Proceed to
   Both DTC B2430 and B2431 are not output.	A
   Both DTC B2430 and B2431 are output.	B
   DTC B2430 or B2431 is output.	C

B → See step   2 

C → See step   7 

A → See step   12 

1. Remove the H-LP relay from the engine room relay block and junction block assembly.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   3 - 5	Voltage not applied between terminals 1 and 2	10 kΩ or higher
   3 - 5	Voltage applied between terminals 1 and 2	Below 1 Ω

   TEXT IN ILLUSTRATION
   
   

   *a	Component without harness connected (H-LP Relay)

NG → REPLACE H-LP RELAY 

OK: Go to next step 

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

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   Relay Terminal 2 - Body ground	Always	11 to 14 V
   Relay Terminal 5 - Body ground	Always	11 to 14 V

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Disconnect the A86 headlight assembly LH connector.
2. Disconnect the A89 headlight assembly RH connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   Relay Terminal 3 - A86-1 (LO)	Always	Below 1 Ω
   Relay Terminal 3 - A89-1 (LO)	Always	Below 1 Ω
   Relay Terminal 3 - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Disconnect the 3D instrument panel junction block assembly connector.
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   Relay Terminal 1 - 3D-12	Always	Below 1 Ω
   Relay Terminal 1 - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Remove the instrument panel junction block assembly. Refer to REMOVAL [09/2014 - ] .
2. Remove the main body ECU (multiplex network body ECU) from the instrument panel junction block assembly.
3. Measure the resistance according to the value(s) in the table below.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   TEXT IN ILLUSTRATION
   
   

   *a

   Component without harness connected (Instrument Panel Junction Block Assembly)

   -

   -

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   3D-12 - MB-15 (HRLY)	Always	Below 1 Ω

NG → See step   14 

OK → See step   13 

1. Disconnect the A86 or A89 headlight assembly connector.
2. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   LH SIDE (DTC B2430)
   
   

   Tester Connection	Condition	Specified Condition
   A86-1 (LO) - Body ground	Ignition switch off, light control switch in head position	11 to 14 V

   RH SIDE (DTC B2431)
   
   

   Tester Connection	Condition	Specified Condition
   A89-1 (LO) - Body ground	Ignition switch off, light control switch in head position	11 to 14 V

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

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

   Standard Resistance

   LH SIDE (DTC B2430)
   
   

   Tester Connection	Condition	Specified Condition
   A86-4 (E) - Body ground	Always	Below 1 Ω

   RH SIDE (DTC B2431)
   
   

   Tester Connection	Condition	Specified Condition
   A89-4 (E) - Body ground	Always	Below 1 Ω

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

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

   Standard Voltage

   LH SIDE (DTC B2430)
   
   

   Tester Connection	Condition	Specified Condition
   A86-2 (S) - Body ground	Ignition switch ON, light control switch in head position	11 to 14 V

   RH SIDE (DTC B2431)
   
   

   Tester Connection	Condition	Specified Condition
   A89-2 (S) - Body ground	Ignition switch ON, light control switch in head position	11 to 14 V

NG → See step   11 

OK: Go to next step 

1. Replace the headlight unit with a new or known good one. Refer to REMOVAL [09/2014 - ] .
2. Check for DTCs. Refer to DTC CHECK / CLEAR [09/2014 - ] .

   OK

   DTC B2430 or B2431 is not output.

NG → See step   13 

OK → END (HEADLIGHT UNIT WAS DEFECTIVE) 

1. Disconnect the I12 main body ECU (multiplex network body ECU) connector.
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   LH SIDE (DTC B2430)
   
   

   Tester Connection	Condition	Specified Condition
   I12-24 (LLEW) - A86-2 (S)	Always	Below 1 Ω
   I12-24 (LLEW) - Body ground	Always	10 kΩ or higher

   RH SIDE (DTC B2431)
   
   

   Tester Connection	Condition	Specified Condition
   I12-21 (RLEW) - A89-2 (S)	Always	Below 1 Ω
   I12-21 (RLEW) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   13