DTC P26CA-14: Engine Coolant Pump Circuit Short to Ground or Open [10/2018 - ]: Procedure

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Disconnect the water inlet housing with water pump sub-assembly connector.
2. Turn the power switch on (IG).
3. Enter the following menus: Powertrain / Engine / Active Test / Activate the Electric Water Pump.

   Powertrain > Engine > Active Test 

   Tester Display
   Activate the Electric Water Pump

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

   Standard

   Tester Connection	Condition	Specified Condition
   C17-2 (SWP) - Body ground	Power switch on (IG), 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.
   • If the resistance fluctuates after turning the power switch on (IG), it can be determined that the ECM is in fail-safe mode.

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE WATER INLET HOUSING WITH WATER PUMP SUB-ASSEMBLY. Refer to  REMOVAL [10/2018 - ] 

Result: 

NG 

See step  2

1. Disconnect the water inlet housing with water pump sub-assembly 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
   C17-2 (SWP) - C34-50 (WPO)	Always	Below 1 Ω
   C17-2 (SWP) or C34-50 (WPO) - Body ground	Always	10 kΩ or higher

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE ECM. Refer to  REMOVAL [10/2018 - 07/2022]  Refer to  REMOVAL [07/2022 - ] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR