DTC B1473/73: A/C Inverter Start-up Signal System Malfunction: Procedure

1. Using the Techstream, check if the CAN communication system is functioning normally.

   Result

   Result	Proceed to
   CAN DTC is not output	A
   CAN DTC is output (w/ Smart Key System)	B
   CAN DTC is output (w/o Smart Key System)	C

B → See step   5 

C → See step   10 

A: Go to next step 

1. Using the Techstream, check if the hybrid control system is functioning normally.

   Result

   Result	Proceed to
   Only DTC B1473/73 is output	A
   DTCs B1473/73 and P3108-536 are output simultaneously (B1498/98 is not output)
   DTCs B1473/73 and B1498/98 are output simultaneously (P3108-536 is not output)	B
   DTCs B1473/73, B1498/98 and P3108-536 are output simultaneously
   DTCs other than P3108-536 are output for hybrid control system	C

B → See step   6 

C → See step   7 

A: Go to next step 

1. Disconnect the A65 hybrid vehicle control ECU connector.
2. Disconnect the B48 compressor connector.
   Fig 1: Identifying Harness And Connector (Hybrid Vehicle Control ECU - Compressor With Motor Assembly)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   WARNING:

   Do not disconnect the connector on the high-voltage side.

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

   Standard resistance

   Tester Connection	Condition	Specified Condition
   A65-20 (STB) - B48-4 (STB1)	Always	Below 1 Ω
   A65-20 (STB) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Reconnect the B48 compressor connector.
2. Measure the voltage according to the value(s) in the table below.
   Fig 2: Checking Harness And Connector (Compressor With Motor Assembly - Body Ground)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard voltage

   Tester Connection	Switch Condition	Specified Condition
   A65-20 (STB) - Body ground	Ignition switch ON	11 to 14 V
   A65-20 (STB) - Body ground	Ignition switch off	Below 1 V

NG → See step   8 

OK → See step   9