Inspection Procedure

HINT:

Although each DTC title says "Coolant Flow Control Valve", these DTCs are related to the water valve.

HINT:

• To check the coolant heat storage (CHS) system, the ECM may cause the water pump of the CHS system to operate 5 hours after the power switch has been turned OFF.
• Read freeze frame data using Techstream. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air/fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction.

1. CHECK ECM (WBAD - E2 VOLTAGE) 
   1. Turn the power switch ON (IG).
   2. Measure the voltage between the terminals WBAD and E2 of the E4 and E7 ECM connectors.

      Standard voltage 

      VOLTAGE SPECIFICATION
      
      

      Water Valve	Specified Condition
      Valve position "A" (Preheat mode)	Approximately 2.5 V
      Valve position "B" (Recovering mode)	Approximately 3.5 V
      Valve position "C" (Normal Operation)	Approximately 4.5 V

      HINT:

      After the HV main system is turned OFF (READY to IG OFF condition), the valve position will be set to position A.

      Fig 1: Identifying E4 And E7 Connector Terminal

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK: CHECK FOR INTERMITTENT PROBLEMS 

   NG: Go to next step 

2. INSPECT WATER M/BRACKET VALVE ASSEMBLY 
   1. Disconnect the W5 water valve connector.
   2. Measure the resistance between terminals WSL1 and WSL2 of the water valve connector.
   3. Measure the resistance between terminals WSAD and E2 of the water valve connector.

      Standard resistance 

      TESTER CONNECTION SPECIFIED CONDITION
      
      

      Tester Connection	Specification Condition
      1 (WSL1) - 2 (WSL2)	Approximately 0.04 kΩ
      5 (WSAD) - 6 (E2)	0.2 to 5.7 kΩ

      Fig 2: Identifying W5 Water Valve Connector

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   NG: REPLACE WATER W/BRACKET VALVE ASSEMBLY 

   OK: Go to next step 

3. CHECK HARNESS AND CONNECTOR (WATER VALVE - ECM) 
   1. Disconnect the W5 water valve connector.
      Fig 3: Identifying W5 Water Valve Connector

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   2. Disconnect the E4 and E7 ECM connectors.
   3. Measure the resistance according to the value(s) in the table below.

      Standard resistance (Check for open) 

      RESISTANCE REFERENCE
      
      

      Tester Connection	Specified Condition
      W5-5 (Water valve) - E7-20 (WBAD)	Below 1 Ω
      W5-4 (Water valve) - E4-18 (VC)	Below 1 Ω
      W5-6 (Water valve) - E4-28 (E2)	Below 1 Ω

      Fig 4: Identifying E4 And E7 ECM Connectors

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard resistance (Check for short) 

      TESTER CONNECTION SPECIFIED CONDITION
      
      

      Tester Connection	Specified Condition
      W5-5 (Water valve) or E7-20 (WBAD) - Body ground	10 kΩ or higher

   4. Reconnect the water valve connector.
   5. Reconnect the ECM connectors.

   NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

   OK: REPLACE ECM