P261C on Audi
Coolant Pump "B" Control Circuit Low
P261C on Audi vehicles indicates coolant pump "b" control circuit low. Au7o has documented this code across 5 Audi models — most commonly on A4 allroad, A5, A5 Sportback. 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. Typical repair costs on Audi range from $300 to $3,500, depending on the specific model and root cause.
Common Causes of P261C
- •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)
P261C on Audi by Model
Audi A4 allroad(1 issue)
- Electric Water Pump Premature Failure2013-2024
The EA888 2.0T engine uses an electric water pump that is prone to premature failure, typically between 60,000 and 100,000 miles. The internal impeller can crack or the electric motor can fail, causing loss of coolant circulation and potential overheating. This is the same issue affecting A4, A5, and Q5 models with the EA888.
Audi A5(1 issue)
- Water Pump and Thermostat Failure2008-2023
Water pump failures are common across all A5 and S5 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 timing belt/chain driven in many models, so replacement during timing service saves labor. Thermostat housings also crack from heat cycling, causing coolant leaks and erratic temperature readings. Symptoms include coolant puddles under the car, overheating in traffic, and temperature gauge fluctuations. Ignoring a failed water pump can cause severe engine overheating, warped cylinder heads, and blown head gaskets ($3,000-$5,000). The 3.0T S5 also has an electric auxiliary water pump for turbo cooling that fails separately.
Audi A5 Sportback(1 issue)
- Electric Water Pump Failure (2.0T)2018-2025
The auxiliary electric water pump for the turbo cooling circuit fails, causing potential turbo overheating after engine shutdown. The pump impeller seizes or the electronic controller faults.
Audi Q3(1 issue)
- Water Pump Failure and Coolant Leak2015-2023
The EA888 water pump in the Q3 uses a plastic impeller that can crack or separate from the shaft, causing coolant leaks and loss of cooling. The thermostat housing gasket is also prone to failure in the same mileage range. Both components are located on the front of the engine and failures typically occur between 60,000 and 100,000 miles.
Audi S5(1 issue)
- EA839 Water Pump Internal Leak and Vacuum System Contamination (2.9T)2018-2024
The B9/B9.5 Audi S5 (2018-2024) with the EA839 2.9T twin-turbo V6 suffers from a particularly insidious water pump failure. Unlike typical water pumps that leak externally, the EA839 water pump leaks INTERNALLY. The pump uses vacuum to operate a slide valve controlling impeller actuation. When the internal seals fail, coolant is drawn into the vacuum system and migrates into other components where coolant should never be present—including the brake booster, turbo wastegate actuators, and other vacuum-operated systems. This makes the failure especially dangerous as it can affect braking and boost control simultaneously. New German Performance and AudiWorld forums describe this as a 'when, not if' failure on EA839 engines. Failures typically occur between 40,000-70,000 miles.
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View P261C across all makes →Frequently Asked Questions
What does P261C mean on 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 specifically, this code is documented across 5 models.
What causes P261C on Audi vehicles?▼
Common causes on Audi: 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. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P261C on a Audi?▼
Repair costs on Audi range from $300 to $3,500, depending on the specific model and root cause.
Which Audi models have P261C documented?▼
Au7o has documented P261C on 5 Audi models: A4 allroad, A5, A5 Sportback, Q3, S5.