Back-up Light Circuit: Procedure

1. Disconnect the 1H No. 1 integration relay connector.
2. Measure the voltage and resistance according to the value(s) in the table below.

   Standard Voltage

   Tester Connector	Condition	Specified Condition
   1H-7 (BATT) - Body ground	Power switch off	11 to 14 V

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   1H-3 (GND2) - Body ground	Always	Below 1 Ω

3. Disconnect the 1G No. 1 integration relay connector.
4. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   1G-22 (GND1) - Body ground	Always	Below 1 Ω

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Disconnect the A21 power management control ECU connector.
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   1G-13 (BKUP) - A21-15 (BL)	Always	Below 1 Ω
   1G-13 (BKUP) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Disconnect the S18 or R17 rear combination light assembly connector.
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   1G-3 (BCK1) - S18-3 (B)	Always	Below 1 Ω
   1G-3 (BCK1) - R17-3 (B)	Always	Below 1 Ω
   1G-3 (BCK1) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Temporarily replace the No. 1 integration relay with a new or normally functioning one. Refer to REMOVAL .
2. Check that the back-up lights operate normally.

   OK

   The back-up lights operate normally.

NG → See step   5 

OK → END (NO. 1 INTEGRATION RELAY WAS DEFECTIVE)