P26BB on 2021-2022 Chevrolet Silverado 1500 (LT, RST, LTZ, High Country) — Engine Coolant Bypass Valve "C" Range/Performance
1 vehicles · 1 makes
Most Reported On
P26BB is an OBD-II diagnostic trouble code meaning “Engine Coolant Bypass Valve "C" Range/Performance.” A generic OBD-II code indicating engine coolant bypass valve C is electrically operating but its performance (actual coolant flow/temperature response versus expected) is out of range. On some vehicles this can appear transiently during the valve break-in period and self-clear after further actuations. This code is most commonly reported on 2021-2022 Chevrolet Silverado 1500 (LT, RST, LTZ, High Country).
Common Causes
Diagnostic Tools
To diagnose P26BB, 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+).
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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)
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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
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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.
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- Oil reset, EPB, BMS, TPMS, injector coding
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FAQ
What does P26BB mean?
P26BB stands for "Engine Coolant Bypass Valve "C" Range/Performance." A generic OBD-II code indicating engine coolant bypass valve C is electrically operating but its performance (actual coolant flow/temperature response versus expected) is out of range. On some vehicles this can appear transiently during the valve break-in period and self-clear after further actuations.
What are the most common causes of P26BB?
The most common causes of P26BB are: Coolant bypass valve C sticking or slow to respond, Debris/contamination affecting valve travel, Valve break-in variation (low mileage), Coolant flow restriction, Valve wear or internal fault, Faulty ECM (rare). The specific cause varies by vehicle.
How much does it cost to fix P26BB?
Repair costs vary widely depending on the root cause and vehicle.
Which vehicles are affected by P26BB?
Au7o has documented P26BB across 1 vehicle models from 1 manufacturers: Chevrolet.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.