DTC P26CA-14: Engine Coolant Pump Circuit Short to Ground or Open [03/2023 - ]: Procedure
WARNING: This page is about a different car, the 2025 Lexus NX 250, 2024 Lexus NX 250, 2023 Lexus NX 250, and 2022 Lexus NX 250. However, it is still accessible from the selected car via links, so may be relevant.
- INSPECT ECM (INTERNAL CIRCUIT)
- Disconnect the engine water pump assembly (water inlet housing) connector.
- 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 B31-2 (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 [11/2021 - ]
Result:
NG
See step 2
- CHECK HARNESS AND CONNECTOR (ENGINE WATER PUMP ASSEMBLY (WATER INLET HOUSING) - ECM)
- 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 (for TMMC Made)
Tester Connection Condition Specified Condition B31-2 (SWP) - B94-50 (WPO) Always Below 1 Ω B31-2 (SWP) or B94-50 (WPO) - Body ground Always 10 kΩ or higher Standard Resistance (for TMC Made)
Tester Connection Condition Specified Condition B31-2 (SWP) - B50-50 (WPO) Always Below 1 Ω B31-2 (SWP) or B50-50 (WPO) - Body ground Always 10 kΩ or higher Result
Proceed to OK NG
Result:
OK
REPLACE ECM. Refer to REMOVAL [11/2021 - ]
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR