P261B on Toyota
Coolant Pump "B" Control Circuit Range/Performance
P261B on Toyota vehicles indicates coolant pump "b" control circuit range/performance. Au7o has documented this code across 1 Toyota model — most commonly on Prius. This code sets when the engine control module commands the electric (auxiliary) coolant pump "B" but the circuit's behavior or feedback does not match what is expected for the commanded state. Coolant pump "B" is typically an electric auxiliary pump that helps circulate coolant for engine, turbo, hybrid, or A/C-related cooling. A range/performance fault means the pump or its control circuit is responding sluggishly or incorrectly, which risks overheating if coolant is not moving properly. Typical repair costs on Toyota range from $250 to $800, depending on the specific model and root cause.
Common Causes of P261B
- •Failing or seized electric auxiliary coolant pump
- •Wiring or connector fault in the pump control circuit
- •Corroded or loose pump connector
- •Low coolant level or air in the system
- •Faulty pump relay or power supply
- •Control module (ECM) driver fault (less common)
P261B on Toyota by Model
Toyota Prius(1 issue)
- Electric Engine Coolant Pump Failure Causing Overheat Shutdown (P261B / P261C)2010-2015
Unlike a belt-driven pump, the 2ZR-FXE engine coolant pump is a brushless electric unit commanded by duty cycle from the ECM. The internal motor/controller degrades and the pump slows or stops, so coolant stops circulating through the engine. The ECM detects the speed feedback falling below threshold and sets P261B (or P261C), lights the check engine and hybrid warning lights, and will shut the gas engine down to protect it, leaving the car crawling on battery only. Toyota addressed it with T-SB-0143-10 and a revised pump design; it is one of the most-reported repairs on third-gen Prius, Prius v, Prius c and Lexus CT200h.
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What does P261B mean on Toyota?▼
P261B stands for "Coolant Pump "B" Control Circuit Range/Performance." This code sets when the engine control module commands the electric (auxiliary) coolant pump "B" but the circuit's behavior or feedback does not match what is expected for the commanded state. Coolant pump "B" is typically an electric auxiliary pump that helps circulate coolant for engine, turbo, hybrid, or A/C-related cooling. A range/performance fault means the pump or its control circuit is responding sluggishly or incorrectly, which risks overheating if coolant is not moving properly. On Toyota specifically, this code is documented across 1 model.
What causes P261B on Toyota vehicles?▼
Common causes on Toyota: Failing or seized electric auxiliary coolant pump, Wiring or connector fault in the pump control circuit, Corroded or loose pump connector, Low coolant level or air in the system, Faulty pump relay or power supply. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P261B on a Toyota?▼
Repair costs on Toyota range from $250 to $800, depending on the specific model and root cause.
Which Toyota models have P261B documented?▼
Au7o has documented P261B on 1 Toyota model: Prius.