DTC P26CA-14: Engine Coolant Pump Circuit Short to Ground or Open [10/2022 - 08/2023]: Procedure
WARNING: This page is about a different car, the 2025 Lexus RX 450h+, 2025 Lexus RX 350h, 2024 Lexus RX 450h+, 2024 Lexus RX 350h, and 2023 Lexus RX 350h. However, it is still accessible from the selected car via links, so may be relevant.
- INSPECT ECM (INTERNAL CIRCUIT)
Pre-procedure1
- Disconnect the engine water pump assembly (water inlet housing) connector.
- Perform the Active Test using the GTS.
Powertrain > Engine > Active Test
Tester Display Activate the Electric Water Pump - Measure the resistance according to the value(s) in the table below.
Standard
Tester Connection Condition Specified Condition B77-2 (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
Post-procedure1
- None.
Result:
OK
REPLACE ENGINE WATER PUMP ASSEMBLY (WATER INLET HOUSING). Refer to REMOVAL [10/2022 - ]
Result:
NG
See step 2
- CHECK HARNESS AND CONNECTOR (ENGINE WATER PUMP ASSEMBLY (WATER INLET HOUSING) - ECM)
Pre-procedure1
- Disconnect the engine water pump assembly (water inlet housing) connector.
- Disconnect the ECM connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition Result B77-2 (SWP) - B28-50 (WPO) Always Below 1 Ω Ω B77-2 (SWP) or B28-50 (WPO) - Body ground Always 10 kΩ or higher kΩ Result
Proceed to OK NG
Post-procedure1
- None.
Result:
OK
REPLACE ECM. Refer to REMOVAL [10/2022 - 08/2023]
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR