P261B: Coolant Pump "B" Control Circuit Range/Performance
5 vehicles · 5 makes · $250-$2,200 repair
Most Reported On
P261B is an OBD-II diagnostic trouble code meaning “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. This code is most commonly reported on 2012-2013 BMW 3 Series, 2020 Cadillac CT5, and 2020-2025 Mercedes-Benz GLE (GLE 450 4MATIC, AMG GLE 53), plus 2 other vehicles, with repair costs ranging from $250 to $2,200.
Common Causes
Typical Repair Cost
Based on 5 documented vehicle-specific issues. Actual cost depends on root cause and vehicle.
Diagnostic Tools
This is a powertrain code, so a basic OBD-II reader can read it. These read P261B.
ANCEL AD310 Classic OBD-II Scanner
by ANCEL
A simple code reader for engine (P) codes on many compatible OBD-II vehicles. It does not support every vehicle or hybrid/EV application, and it does NOT read body, chassis or network codes; confirm exact-vehicle compatibility before buying.
- Read & clear engine (P) codes
- View freeze frame data
- I/M readiness status
- No batteries or app needed
BlueDriver Pro Bluetooth Scanner
by BlueDriver
Bluetooth scanner with a companion app that reads beyond the engine module — ABS, SRS and transmission — plus manufacturer-specific codes on many vehicles.
- Enhanced diagnostics (ABS, SRS, transmission)
- Repair Reports with verified fixes
- Smog check readiness
- Free app (iOS & Android)
LAUNCH CRP123X V3.0 Elite OBD-II Scanner
by LAUNCH
Handheld scanner covering the four major systems (engine, transmission, ABS, SRS) with live data streaming and graphing.
- Engine, transmission, ABS, SRS diagnostics
- Live data stream & graphing
- AutoVIN for vehicle identification
- Free lifetime updates via Wi-Fi
Autel MaxiCOM MK808S Diagnostic Tool
by Autel
Shop-level tablet with all-system coverage and bi-directional control, so you can command a module rather than only read it.
- All-system diagnostics (25+ modules)
- Bi-directional control & active tests
- Oil reset, EPB, BMS, TPMS, injector coding
- 7-inch touchscreen with Android OS
What you can do yourself, and what needs a shop
Reading the code, clearing it, and watching whether it returns is a driveway job with the right scanner. These steps are not:
- Module programming or software updates — needs the manufacturer software or a J2534 pass-through with a paid subscription.
- Replacing a control module — most are VIN-programmed and immobilizer-registered, so a new one does nothing until it is coded to your car.
- Airbag/SRS component work — a stored fault can deploy a live device.
If the vehicle is still under warranty, check for an open recall or technical service bulletin before buying anything — the repair may already be covered.
As an Amazon Associate, we earn from qualifying purchases. Prices are approximate and may vary.
Vehicles Affected (5)
FAQ
What does P261B mean?
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.
What are the most common causes of P261B?
The most common causes of P261B are: 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). The specific cause varies by vehicle.
How much does it cost to fix P261B?
Repair costs for P261B range from $250 to $2,200, depending on the vehicle and root cause.
Which vehicles are affected by P261B?
Au7o has documented P261B across 5 vehicle models from 5 manufacturers: Audi, BMW, Cadillac, Mercedes-Benz, Toyota.
Sources (8)
- TSBBMW SIB 01 13 21 - E92/E93 Electric Coolant-Pump Settlement and Diagnostic Scope
- TSBGM Customer Satisfaction Program N202320510 - Water Pump Failure
- articleMercedes M256 Engine: Full Guide and Known Issues - Mercedes Assistance
- article2018-2023 Mercedes M256 Engine Oil Filter Adapter Leaks - Go-Parts
- TSBAudi TSB 2071515/1 - 2020-2024 A6 2.0 TFSI coolant-pump leak diagnosis
- Forum2010 Prius with P261B water pump failure - PriusChat
- ForumP261B Code Water pump failure - PriusChat
- ForumEngine Code P261B Water Pump - PriusChat
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.