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P261CCriticalPowertrain

P261C: Coolant Pump "B" Control Circuit Low

2 vehicles · 2 makes · $250-$1,500 repair

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Most Reported On

2005-2023Audi A62010-2015Toyota PriusPrius +2

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 2005-2023 Audi A6, and 2010-2015 Toyota Prius (Prius, Prius v, Prius Plug-in Hybrid), with repair costs ranging from $250 to $1,500.

On This Page

  • Common Causes
  • Repair Cost
  • Vehicles (2)
  • Related Codes
  • FAQ
  • Sources (4)

Makes

  • Audi1
  • Toyota1
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Common Causes

1Control wiring shorted to ground
2Internally shorted/failed coolant pump
3Corroded or damaged pump connector
4Chafed wiring contacting chassis ground
5Faulty pump relay or power circuit
6ECM/PCM driver circuit fault (rare)

Typical Repair Cost

$250 - $1,500

Based on 2 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 P261C.

Reads P codes$20–$40

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
Check Price on Amazon
Reads P codes$90–$120

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)
Check Price on Amazon
Reads P codes$180–$230

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
Check Price on Amazon
Reads P codes$350–$450

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
Check Price on Amazon

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 (2)

Audi P261C page →
A6Moderate

Water Pump and Thermostat Failure (Overheating)

2005-2023$800-$1,500
Toyota P261C page →
PriusCritical

Electric Engine Coolant Pump Failure Causing Overheat Shutdown (P261B / P261C)

2010-2015$250-$800

Related Codes (8)

P2610ECM/PCM Internal Engine Off Timer PerformanceP2611A/C Refrigerant Distribution Valve Control Circuit/OpenP2612A/C Refrigerant Distribution Valve Control Circuit LowP2613A/C Refrigerant Distribution Valve Control Circuit HighP0013"B" Camshaft Position Actuator Circuit/Open (Bank 1)P0020Camshaft Position 'A' Actuator Circuit (Bank 2)P0023"B" Camshaft Position Actuator Circuit/Open (Bank 2)P0025"B" Camshaft Position - Timing Over-Retarded (Bank 2)

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 $250 to $1,500, depending on the vehicle and root cause.

Which vehicles are affected by P261C?

Au7o has documented P261C across 2 vehicle models from 2 manufacturers: Audi, Toyota.

Sources (4)

  • 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
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Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.

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