DTC P26AC-11: Engine Coolant Bypass Valve "B" Circuit Short to Ground; DTC P26AC-15: Engine Coolant Bypass Valve "B" Circuit Short to Battery or Open [08/2020 - ]: Procedure

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Disconnect the flow shutting valve (for ATF control) (No. 1 water by-pass hose) connector.
2. Turn the ignition switch to ON.
3. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   C26-2 - Body ground	Ignition switch ON	11 to 14 V

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR (EFI-MAIN NO. 1 RELAY - FLOW SHUTTING VALVE (FOR ATF CONTROL)) 

Result: 

OK 

See step  2

1. Inspect the flow shutting valve (for ATF control) (No. 1 water by-pass hose).

   Refer to INSPECTION [11/2018 - ]

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPLACE FLOW SHUTTING VALVE (FOR ATF CONTROL) (NO. 1 WATER BY-PASS HOSE). Refer to  REMOVAL [08/2020 - 10/2022]  , or refer to  REMOVAL [10/2022 - 10/2023]  , or refer to  REMOVAL [10/2023 - ] 

Result: 

OK 

See step  3

1. Disconnect the flow shutting valve (for ATF control) (No. 1 water by-pass hose) 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
   C26-1 - C40-41 (WSV2)	Always	Below 1 Ω
   C26-1 or C40-41 (WSV2) - Body ground and other terminals	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