DTC P26CA-14: Engine Coolant Pump Circuit Short to Ground or Open [08/2020 - ]: Procedure

1. Disconnect the engine water pump assembly (water inlet housing) connector.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Front view of wire harness connector (to Engine Water Pump Assembly (Water Inlet Housing))

2. Measure the resistance while maintaining at 3000 rpm.

   Powertrain > Engine > Active Test 

   Active Test Display
   Activate the Electric Water Pump

   Data List Display
   Electric Water Pump

   Standard

   Tester Connection	Condition	Specified Condition
   C23-2 (SWP) - Body ground	During Active Test	Resistance fluctuates*

   HINT: 

   *: Using the Active Test, duty control of the transistors in the ECM will be performed. Due to the duty control, resistance of the SWP terminal will be unstable during the Active Test. If the resistance fluctuates while performing the Active Test, it can be determined that the transistor is operating. If the transistor does not operate during the Active Test, the ECM may be malfunctioning.

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE ENGINE WATER PUMP ASSEMBLY (WATER INLET HOUSING) 

Refer to REMOVAL [08/2020 - 10/2022] , or refer to REMOVAL [10/2022 - 10/2023] , or refer to REMOVAL [10/2023 - ]

Result: 

NG 

See step  2

1. Disconnect the engine water pump assembly (water inlet housing) connector.
2. Disconnect the ECM connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   C23-2 (SWP) - C40-50 (WPO)	Always	Below 1 Ω
   C23-2 (SWP) or C40-50 (WPO) - Body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE ECM 

Refer to REMOVAL [08/2020 - 10/2022] , or refer to REMOVAL [10/2022 - 10/2023] , or refer to REMOVAL [10/2023 - ]

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR