Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means that the car's computer thinks the backup coolant pump isn't working right. It's like when a fan in your room stops working and can't cool you down.
The P261B code indicates a problem with the secondary or auxiliary coolant pump's control circuit, which is not performing as expected or is stuck in the 'off' position.
The P261B code is triggered when the Engine Control Module (ECM) detects that the auxiliary coolant pump, also known as Coolant Pump B, is not operating within its expected parameters. This could be due to an electrical fault, mechanical failure, or a control circuit issue preventing the pump from activating.
• Engine overheating
• Check Engine Light illuminated
• Reduced engine performance
• Coolant leaks
• Unusual noises from the engine compartment
• Faulty coolant pump B
• Blown fuse or relay for the coolant pump
• Wiring issues such as shorts or open circuits
• Faulty ECM or control module
• Corroded or damaged connectors
ECM: Engine Control Module, the computer that controls engine functions.
Coolant Pump: A device that circulates coolant through the engine to regulate temperature.
• Check for any other related trouble codes.
• Inspect the coolant pump B and its electrical connections.
• Test the fuse and relay associated with the coolant pump.
• Check the wiring for continuity and shorts.
• Test the operation of the coolant pump B.
• Replace the faulty coolant pump B.
• Repair or replace damaged wiring or connectors.
• Replace the blown fuse or faulty relay.
• Reprogram or replace the ECM if necessary.
• OBD-II scanner
• Multimeter
• Basic hand tools (screwdrivers, pliers)
• Coolant system pressure tester
$150 - $600
Moderate
• Toyota Camry
• Ford Fusion
• BMW 3 Series
• Regularly check and maintain coolant levels.
• Inspect electrical connections for corrosion.
• Perform routine vehicle maintenance checks.
Engine Performance
• Avoid driving the vehicle until the issue is resolved to prevent engine damage.
• Consult with a professional mechanic for accurate diagnostics.
Check with the vehicle manufacturer for specific warranty coverage related to the coolant system.
This code has been more frequently reported in vehicles with complex cooling systems that utilize multiple pumps.
High – Driving with this issue can lead to engine overheating and severe damage.
Ignoring this code and continuing to drive can result in engine failure, which may lead to unsafe driving conditions.
• Engine at operating temperature
• Vehicle stationary with engine idling
The auxiliary coolant pump is typically located near the engine or radiator, depending on the vehicle model.
Q: Can I drive my car with a P261B code?
A: It's not recommended to drive with this code active as it can lead to engine overheating.
Q: How can I reset the P261B code?
A: After repairing the issue, use an OBD-II scanner to clear the code. If the problem persists, the code will return.
High-End · Full-system diagnostics
A full-system bidirectional platform aimed at advanced DIY users and professional diagnostic workflows.
Network faults often require full-system access instead of a generic code reader alone.
View on Amazon
Universal · Digital multimeter
A solid entry-level multimeter for voltage, continuity, resistance, and basic electrical troubleshooting.
Helpful for checking voltage drops, grounds, and basic circuit health when modules are not communicating.
View on Amazon
Universal · Wire connectors and repair kit
Useful when diagnosis points toward damaged wiring, corroded terminals, or connector repairs.
Useful if diagnosis points toward damaged connectors, wiring, or terminal repairs.
View on AmazonThese are optional diagnostic tools, not guaranteed fixes. As an Amazon Associate I earn from qualifying purchases.