Inspection Procedure

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 the hand-held tester or the OBDII scan tool. Freeze frame data records the engine condition when malfunction is detected. When troubleshooting, it is useful for determining whether the vehicle was running or stopped, the engine was warmed up or not, the air-fuel ratio was lean or rich, etc. at the time of the malfunction.

1. INSPECT ECM (WBAD - E2 VOLTAGE) 
   Fig 1: DTC P1120, P1122, P1123 Inspecting ECM (WBAD - E2 Voltage)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   1. Turn the power switch ON (IG).
   2. Measure voltage between the terminals WBAD and E2 of the E4 and E7 ECM connectors.
   ECM (WBAD - E2 VOLTAGE) STANDARD (DTC P1120)
   
   

   Water Valve	Voltage V
   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.

   OK: CHECK FOR INTERMITTENT PROBLEMS (See  CHECK FOR INTERMITTENT PROBLEMS   ) 

   NG: Go To Next Step 

2. INSPECT WATER W/BRACKET VALVE ASSY 
   Fig 2: DTC P1120, P1122, P1123 Inspecting Water W/Bracket Valve Assy

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   1. Disconnect the W5 water valve connector.
   2. Measure resistance between terminals WSL1 and WSL2 of the water valve connector.
   3. Measure resistance between terminals WBAD and E2 of the water valve connector.
   WATER W/BRACKET VALVE ASSY (DTC P1120)
   
   

   Terminals	Condition	Resistance kΩ
   1 - 2	Motor resistance	Approximately 0.04
   5 - 6	Sensor resistance	0.2 to 5.7

   NG: REPLACE WATER W/BRACKET VALVE ASSY 

   OK: Go To Next Step 

3. CHECK HARNESS AND CONNECTOR (WATER VALVE - ECM) 
   Fig 3: DTC P1120, P1122, P1123 Checking Harness And Connector (Water Valve - ECM) (1 Of 2)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   1. Disconnect the W5 water valve connector.
   2. Disconnect the E4 and E7 ECM connectors.
   3. Check the resistance between the wire harness side connectors.
      STANDARD (CHECK FOR OPEN) (DTC P1120):
      
      

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

      STANDARD (CHECK FOR SHORT) (DTC P1120):
      
      

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

   4. Reconnect the water valve connector.
   5. Reconnect the ECM connectors.
   Fig 4: DTC P1120, P1122, P1123 Checking Harness And Connector (Water Valve - ECM) (2 Of 2)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

   OK: REPLACE ECM (See  ENGINE CONTROL SYSTEM  )