Heater Water Pump Circuit: 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   9 

C → See step   13 

A: Go to next step 

1. Connect the Techstream to the DLC3.
2. Turn the ignition switch to ON and turn the Techstream on.
3. Select the item below in the Active Test and check that the relay operates.
   ACTIVE TEST / AIR CONDITIONER:
   
   

   Tester Display	Test Part	Control Range	Diagnostic Note
   Water Pump	A/C W/P relay	OFF, ON	-

   OK

   Heater water pump operates smoothly.

NG → See step   3 

OK → See step   10 

1. Remove the A/C W/P relay from the engine room No. 3 relay block.
   Fig 1: Identifying A/C W/P Relay Engine Room No. 3 Relay Block

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the resistance according to the value(s) in the table below.

   Standard resistance

   Tester Connection	Specified Condition
   3 - 5	10 kΩ or higher
   3 - 5	Below 1 Ω (When battery voltage is applied to terminals 1 and 2)

NG → REPLACE RELAY (A/C W/P) 

OK: Go to next step 

1. Measure the voltage according to the value(s) in the table below.
   Fig 2: Identifying A/C W/P Relay Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard voltage

   Tester Connection (Symbols)	Switch Condition	Specified Condition
   Relay block A/C W/P relay terminal 1 - Body ground	Always	11 to 14 V
   Relay block A/C W/P relay terminal 3 - Body ground	Always	11 to 14 V

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Install the A/C W/P relay.
2. Disconnect the A65 hybrid vehicle control ECU connector.
   Fig 3: Identifying Harness And Connector (Hybrid Vehicle Control ECU - Battery)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Measure the voltage according to the value(s) in the table below.

   Standard voltage

   Tester Connection	Condition	Specified Condition
   A65-3 (WP) - Body ground	Always	11 to 14 V

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Disconnect the A35 pump connector.
2. Connect a positive (+) lead from the battery to terminal 2 and a negative (-) lead to terminal 1.
   Fig 4: Identifying Heater Water Pump Assembly With Connector End View

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK

   Heater water pump operates smoothly.

   NOTE:

   Complete this inspection within 10 seconds if there is no water in the heater water pump assembly.

NG → See step   11 

OK: Go to next step 

1. Measure the resistance according to the value(s) in the table below.
   Fig 5: Checking Harness And Connector (Heater Water Pump Assembly - Body Ground)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard resistance

   Tester Connection	Condition	Specified Condition
   A35-1 - Body ground	Always	Below 1 Ω

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Remove the A/C W/P relay from the engine room No. 3 relay block.
   Fig 6: Identifying Harness And Connector (Heater Water Pump Assembly - Engine Room No. 3 Relay Block)

   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
   A35-2 - Relay block A/C W/P relay terminal 5	Always	Below 1 Ω
   A35-2 - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   12