P261C: Coolant Pump "B" Control Circuit Low
8 vehicles · 1 makes · $300-$8,000 repair
Most Reported On
P261C is an OBD-II diagnostic trouble code meaning “Coolant Pump "B" Control Circuit Low.” This code indicates the engine control module detected an abnormally low voltage (a short to ground) on the control circuit for electric coolant pump "B." That auxiliary pump circulates coolant to support engine, turbocharger, hybrid, or A/C cooling. A low/short condition means the circuit is not behaving correctly, and the computer can lose reliable control of the pump, which risks inadequate cooling and overheating of the affected system. This code is most commonly reported on 2013-2024 Audi A4 allroad (Premium, Premium Plus, Prestige), 2015-2023 Audi Q3 (Premium, Premium Plus, Prestige, S line), and 2013-2018 Audi S8 (S8), plus 5 other vehicles, with repair costs ranging from $300 to $8,000.
Common Causes
Typical Repair Cost
Based on 8 documented vehicle-specific issues. Actual cost depends on root cause and vehicle.
Diagnostic Tools
To diagnose P261C, you'll need an OBD-II scanner. Here are our recommendations at every price point.
ANCEL AD310 Classic OBD-II Scanner
by ANCEL
A simple, affordable code reader that reads and clears check engine codes. Great for quick diagnostics on any OBD-II vehicle (1996+).
- Read & clear engine codes
- View freeze frame data
- I/M readiness status
- No batteries or app needed
BlueDriver Pro Bluetooth Scanner
by BlueDriver
Bluetooth OBD-II scanner with a free companion app. Provides enhanced diagnostics, smog readiness, and repair reports sourced from a database of verified fixes.
- Enhanced diagnostics (ABS, SRS, transmission)
- Repair Reports with verified fixes
- Smog check readiness
- Free app (iOS & Android)
LAUNCH CRP123X OBD-II Scanner
by LAUNCH
A professional-grade handheld scanner that reads all 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 diagnostic tablet with bi-directional control, active tests, and full system coverage. Ideal for serious DIYers and small shops.
- All-system diagnostics (25+ modules)
- Bi-directional control & active tests
- Oil reset, EPB, BMS, TPMS, injector coding
- 7-inch touchscreen with Android OS
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Vehicles Affected (8)
Electric Water Pump Premature Failure
Water Pump Failure and Coolant Leak
Coolant Leak from Thermostat Housing and Water Pump Area (4.0T)
Electronic Water Pump Failure (2.0T)
Electric Water Pump Failure (2.0T)
EA839 Water Pump Internal Leak and Vacuum System Contamination (2.9T)
EA839 3.0T Water Pump Internal Leak Causing Cascade Failures
Water Pump and Thermostat Failure
FAQ
What does P261C mean?
P261C stands for "Coolant Pump "B" Control Circuit Low." This code indicates the engine control module detected an abnormally low voltage (a short to ground) on the control circuit for electric coolant pump "B." That auxiliary pump circulates coolant to support engine, turbocharger, hybrid, or A/C cooling. A low/short condition means the circuit is not behaving correctly, and the computer can lose reliable control of the pump, which risks inadequate cooling and overheating of the affected system.
What are the most common causes of P261C?
The most common causes of P261C are: Control wiring shorted to ground, Internally shorted/failed coolant pump, Corroded or damaged pump connector, Chafed wiring contacting chassis ground, Faulty pump relay or power circuit, ECM/PCM driver circuit fault (rare). The specific cause varies by vehicle.
How much does it cost to fix P261C?
Repair costs for P261C range from $300 to $8,000, depending on the vehicle and root cause.
Which vehicles are affected by P261C?
Au7o has documented P261C across 8 vehicle models from 1 manufacturers: Audi.
Sources (8)
- TSBAudi TSB - Water Pump Replacement EA888
- videoYouTube - Audi S8 4.0T Thermostat Housing Coolant Leak Repair
- NHTSANHTSA Vehicle Page for 2018 Audi A5 Sportback - includes complaints and recalls
- videoKnown YouTube channel video showing diagnosis and replacement of electric water pump on Audi A5 2.0T
- videoAudi S5 2.9T Water Pump Internal Leak Repair - Detailed Walkthrough
- videoFCP Euro - Audi SQ5 3.0T Water Pump Replacement and Leak Diagnosis
- NHTSANHTSA Complaint #11408386 - 2018 Audi A5 coolant pump/thermostat failure causing coolant leak and overheating warning
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.