P261B on Cadillac
Coolant Pump "B" Control Circuit Range/Performance
P261B on Cadillac vehicles indicates coolant pump "b" control circuit range/performance. Au7o has documented this code across 1 Cadillac model — most commonly on CT5. 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.
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 Cadillac by Model
Cadillac CT5(1 issue)
- Electric Water Pump Circuit Board Failure — Overheat and Limp Mode2020
GM issued a TSB (December 2020) stating the printed circuit board inside the electric water pump on affected CT4/CT5 vehicles may have been manufactured incorrectly, potentially causing a water pump failure; when this occurs the vehicle displays warnings as coolant temperatures rise, the oil pressure gauge falsely indicates high oil pressure, a reduced power/torque message appears, and if ignored the AC is disabled and the driver is told to turn off the engine . The 2.0L LSY turbo-four (base engine in the CT5) is one of the engines susceptible to this water pump failure (the other being the 2.7L L3B, which is not used in the CT5) .
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What does P261B mean on Cadillac?▼
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 Cadillac specifically, this code is documented across 1 model.
What causes P261B on Cadillac vehicles?▼
Common causes on Cadillac: 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 Cadillac?▼
Repair costs vary widely depending on the root cause and specific Cadillac model.
Which Cadillac models have P261B documented?▼
Au7o has documented P261B on 1 Cadillac model: CT5.