DTC P261B: Engine Coolant Pump "B" Control Malfunction; DTC P261C: Engine Coolant Pump "B" Control Circuit Low; DTC P261D: Engine Coolant Pump "B" Control Circuit High [08/2013 - ]: Description
WARNING: This page is about a different car, the 2014 Lexus ES 300h. However, it is still accessible from the selected car via links, so may be relevant.
The ECM controls the engine water pump assembly by calculating the necessary amount of coolant flow based on engine coolant temperature, engine speed and vehicle speed information. The speed of the engine water pump assembly is controlled steplessly using a duty cycle signal sent from the ECM. This optimal control enhances warm-up performance and reduces cooling losses, thus reducing the specific fuel consumption of the engine.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| P261B | Engine water pump assembly speed is less than 900 rpm while the engine water pump assembly is operating (1 trip detection logic). |
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| P261C | Engine water pump assembly output voltage is less than specified value while the engine water pump assembly is operating (1 trip detection logic). |
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| P261D | Engine water pump assembly output voltage is higher than specified value while the engine water pump assembly is operating (1 trip detection logic). |
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