DTC P26CA-14: Engine Coolant Pump Circuit Short to Ground or Open [08/2020 - 08/2021]: Procedure
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2024 Lexus ES 300h, 2023 Lexus ES 300h, 2022 Lexus ES 300h, 2021 Lexus ES 300h, and 2020 Lexus ES 300h. However, it is still accessible from the selected car via links, so may be relevant.
- INSPECT ECM (INTERNAL CIRCUIT)
*a Front view of wire harness connector
(to Water Inlet Housing with Water Pump Sub-assembly)- Disconnect the water inlet housing with water pump sub-assembly connector.
- Turn the power switch on (IG).
- Measure the resistance according to the value(s) in the table below.
Standard
Tester Connection Condition Specified Condition C66-2 (SWP) - Body ground Power switch on (IG) Resistance fluctuates* HINT:
- *: When the connector of the water inlet housing with water pump sub-assembly is disconnected, the ECM will enter fail-safe mode. When the ECM is in fail-safe mode, a continuous duty signal will be output and the resistance will fluctuate as the transistor inside the ECM is turned on an off.
- If the resistance fluctuates while the ECM is in fail-safe mode after the connector of the water inlet housing with water pump sub-assembly is disconnected, it can be determined that the transistor is operating.
- If the transistor does not operate, 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:
NG
REPLACE ECM. Refer to REMOVAL [08/2020 - 08/2021]
Result:
OK
See step 2
- CHECK HARNESS AND CONNECTOR (WATER INLET HOUSING WITH WATER PUMP SUB-ASSEMBLY - ECM)
- Disconnect the water inlet housing with water pump sub-assembly connector.
- Disconnect the ECM connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition C66-2 (SWP) - C88-50 (WPO) Always Below 1 Ω C66-2 (SWP) or C88-50 (WPO) - Body ground Always 10 kΩ or higher Result
Proceed to OK NG
Result:
OK
REPLACE WATER INLET HOUSING WITH WATER PUMP SUB-ASSEMBLY. Refer to REMOVAL [06/2018 - ]
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR