P261C on Audi: How to Diagnose & Fix
Coolant Pump "B" Control Circuit Low
1 Audi model · 1 documented issue · $800-$1,500 repair
P261C on Audi by model: symptoms, diagnosis and fix
Water pump failures are common across all A6 generations due to plastic impeller degradation and seal leaks. Audi uses plastic impellers that crack or disintegrate over time (typically 80,000-120,000 miles), causing coolant leaks and overheating. The water pump is often driven by the timing belt or timing chain, so replacement is recommended during timing service to save labor. Thermostat housings also crack due to heat cycling, causing coolant leaks and erratic temperature readings. Symptoms include coolant leaks under the car, overheating in traffic, temperature gauge fluctuations, and coolant warning lights. Ignoring a failed water pump can lead to severe engine overheating, warped cylinder heads, and blown head gaskets ($3,000-$5,000 repair). Some models have electric auxiliary water pumps that also fail, causing poor heater performance.
Common Symptoms
- Coolant leak under front of car (pink/green puddle)
- Overheating in stop-and-go traffic or at idle
- Temperature gauge rising above normal (middle position)
- Coolant warning light or low coolant message
- No heat from cabin heater (auxiliary pump failure)
- Hissing or gurgling noise from engine bay
- Steam or coolant smell from engine
How to Fix
Replace water pump AND thermostat together ($800-$1,500 with labor). Always use OEM or high-quality aftermarket parts (Rein, Hepu)—cheap pumps fail within 20,000 miles. If water pump is timing belt/chain driven, replace during timing service to save labor. Flush cooling system and refill with OEM Audi G12++ or G13 coolant (do NOT mix types). Inspect coolant hoses and replace if cracked. If auxiliary electric water pump fails, replace separately ($300-$600). Monitor coolant level weekly and address leaks immediately to prevent overheating damage.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Beck/Arnley 131-2517 main engine water pumpCross-refBeck/Arnley 131-2517
Confirm VIN and current fitment before ordering; this is not an auxiliary water pump.
As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.
Owner tips & cautions
- TipPhotograph the suspected leak before cleaning it, then recheck after the system is filled and the car is driven. The Audi bulletin requires the leak to be reproduced rather than inferred from old residue.
- WarningConfirm that the failed component is the main engine coolant pump. The A6 also has auxiliary pumps, and those are different parts with different repair roles.
Sources for this issue (1)
P261C code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P261C mean on a Audi?
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. On Audi it is documented across 1 model: A6.
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 on a Audi?
Published repair estimates on Audi range from $800 to $1,500 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for P261C on a different make?
View P261C across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.