Inspection Procedure

WARNING: This page is about a different car, the 2009 Toyota Prius. However, it is still accessible from the selected car via links, so may be relevant.

PERFORM ACTIVE TEST BY TECHSTREAM (HEADLIGHT)

Select the ACTIVE TEST, use the Techstream to generate a control command, and then check that the headlight illuminates.

Main body ECU

MAIN BODY ECU ACTIVE TEST

Item	Test Details	Diagnostic Note
HEAD LIGHT	Turn headlight relay ON / OFF	-
HEAD LIGHT HI	Turn headlight dimmer relay (headlight dimmer switch in HIGH position) ON / OFF	-

OK : Headlight turns on.

OK : PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

NG : GO TO NEXT STEP

CHECK WIRE HARNESS (ECU - BODY GROUND)
1. Disconnect the B7 ECU connector.
2. Using a service wire, connect B7-20 (HRLY) of the wire harness side and body ground.
  OK : Headlight (Low beam) turns on.
  
  Fig 1: Identifying B7 ECU Connector Terminals
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
NG : Go to step 4

OK : GO TO NEXT STEP
CHECK WIRE HARNESS (ECU - BODY GROUND)
1. Disconnect the B7 ECU connector.
2. Using a service wire, connect B7-20 (HRLY) of the wire harness side and body ground.
3. Using a service wire, connect B7-2 (DRL/DIM) of the wire harness side and body ground.
  OK : Headlight (High beam) turns on.
NG : Go to step 5

OK : PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

CHECK WIRE HARNESS (ECU - BATTERY)

Disconnect the B7 ECU connector.

Fig 3: Identifying B7 ECU Connector Terminals

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Measure the voltage of the wire harness side connector.

Standard voltage

TESTER CONNECTION - SPECIFIED CONDITION

Tester Connection	Specified Condition
B7-20 (HRLY) - Body ground	10 to 14 V

NG : REPAIR OR REPLACE HARNESS AND CONNECTOR (DRIVER SIDE JUNCTION BLOCK - BATTERY)

OK : REPAIR OR REPLACE HARNESS AND CONNECTOR (EACH HEADLIGHT (LOW BEAM) CIRCUIT)

CHECK WIRE HARNESS (ECU - BATTERY)

Disconnect the B7 ECU connector.
Using a service wire, connect B7-20 (HRLY) of the wire harness side and body ground.

Fig 4: Identifying B7 ECU Connector Terminals

Measure the voltage of the wire harness side connector.

Standard voltage

TESTER CONNECTION - SPECIFIED CONDITION

Tester Connection	Specified Condition
B7-2 (DRL/DIM) - Body ground	10 to 14 V

NG : REPAIR OR REPLACE HARNESS AND CONNECTOR (DRIVER SIDE JUNCTION BLOCK - ENGINE ROOM RELAY BLOCK AND JUNCTION BLOCK)

OK : REPAIR OR REPLACE HARNESS AND CONNECTOR (EACH HEADLIGHT (HIGH BEAM) CIRCUIT)