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P26B5ModerateCooling

P26B5: Charge Air Cooler Coolant Temperature Too High

3 vehicles · 2 makes · $400-$1,800 repair

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P26B5 is an OBD-II diagnostic trouble code meaning “Charge Air Cooler Coolant Temperature Too High.” The coolant temperature in the charge air cooler circuit is too high, reducing intercooler effectiveness. This code appears across 3 vehicle models from 2 manufacturers, with repair costs ranging from $400 to $1,800.

On This Page

  • Common Causes
  • Repair Cost
  • Vehicles (3)
  • Related Codes
  • FAQ

Makes

  • Audi1
  • BMW2
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Common Causes

1Failed coolant pump
2Clogged auxiliary radiator
3Low coolant level
4Thermostat fault
5Excessive ambient temperature

Typical Repair Cost

$400 - $1,800

Based on 3 documented vehicle-specific issues. Actual cost depends on root cause and vehicle.

Diagnostic Tools

To diagnose P26B5, you'll need an OBD-II scanner. Here are our recommendations at every price point.

Budget Pick$10–$20

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
Check Price on Amazon
Best Value$90–$120

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)
Check Price on Amazon
Advanced$180–$230

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
Check Price on Amazon
Professional$350–$450

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
Check Price on Amazon

As an Amazon Associate, we earn from qualifying purchases. Prices are approximate and may vary.

Vehicles Affected (3)

A4 allroadCritical

Electric Water Pump Premature Failure

2013-2024$800-$1,8001,100 reports
M240iCritical

Coolant Loss from Expansion Tank and Water Pump Failure

2017-2024$400-$1,200420 reports
M340iCritical

Coolant Loss from Expansion Tank and Water Pump

2020-2024$400-$1,200380 reports

Related Codes (8)

P26B2Charge Air Cooler Coolant Pump Control CircuitP26B4Charge Air Cooler Coolant Pump PerformanceP00B7Engine Coolant Flow Low/PerformanceP0117Engine Coolant Temperature Sensor Circuit LowP0118Engine Coolant Temperature Sensor Circuit HighP0128Coolant Thermostat Below Regulating TemperatureP0217Engine Overtemperature ConditionP0597Thermostat Heater Control Circuit Open

FAQ

What does P26B5 mean?

P26B5 stands for "Charge Air Cooler Coolant Temperature Too High." The coolant temperature in the charge air cooler circuit is too high, reducing intercooler effectiveness.

What are the most common causes of P26B5?

The most common causes of P26B5 are: Failed coolant pump, Clogged auxiliary radiator, Low coolant level, Thermostat fault, Excessive ambient temperature. The specific cause varies by vehicle.

How much does it cost to fix P26B5?

Repair costs for P26B5 range from $400 to $1,800, depending on the vehicle and root cause.

Which vehicles are affected by P26B5?

Au7o has documented P26B5 across 3 vehicle models from 2 manufacturers: Audi, BMW.

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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