EGR Cooler Bypass Valve
A flap that routes recirculated exhaust gas around the EGR cooler instead of through it, so the gas can be returned hot when that is useful and cold when it is not. Cold gas suppresses the formation of nitrogen oxides and is what the cooler exists for; hot gas helps a cold engine and its catalyst reach operating temperature faster, which is why the bypass exists at all. It sits directly in the soot stream, so its characteristic failure is carbon binding the flap and spindle rather than anything electrical — and a valve stuck open raises combustion temperature for real, which pushes the whole downstream emissions system beyond what it was designed to handle.
Also known as: egr bypass valve, cooler bypass flap, egr cooler valve, exhaust gas cooler bypass
Referenced by 16 codes
Codes involving this component (16)
- P040F Exhaust Gas Recirculation Temperature Sensor A/B Correlation Moderate
- P04DA Closed Loop Exhaust Gas Recirculation Control At Limit — Flow Too High Moderate
- P245B Exhaust Gas Recirculation Cooler Bypass Control Circuit Range/Performance Bank 1 Moderate
- P245D Exhaust Gas Recirculation Cooler Bypass Control Circuit High Bank 1 Moderate
- P24A5 Exhaust Gas Recirculation Cooler Bypass Control Stuck/Open Bank 1 Moderate
- P26FB Exhaust Gas Recirculation Cooler Bypass Control Stuck Closed Bank 1 Moderate
- P245A Exhaust Gas Recirculation Cooler Bypass Control Circuit/Open Bank 1
- P245C Exhaust Gas Recirculation Cooler Bypass Control Circuit Low Bank 1
- P248E Exhaust Gas Recirculation Cooler Bypass Control Circuit/Open Bank 2
- P248F Exhaust Gas Recirculation Cooler Bypass Control Circuit Range/Performance Bank 2
- P249A Exhaust Gas Recirculation Cooler Bypass Position Sensor Circuit High Bank 2
- P249B Exhaust Gas Recirculation Cooler Bypass Position Sensor Circuit Intermittent/Erratic Bank 2
- P24A6 Exhaust Gas Recirculation Cooler Bypass Control Stuck/Open Bank 2
- P24C4 Exhaust Gas Recirculation Cooler Bypass Position Sensor Exceeded Learning Limit Bank 1
- P24C5 Exhaust Gas Recirculation Cooler Bypass Position Sensor Exceeded Learning Limit Bank 2
- P26FC Exhaust Gas Recirculation Cooler Bypass Control Stuck Closed Bank 2
Other components in Exhaust and Emissions
- Oxygen Sensor 326
- EGR Valve 150
- Catalytic Converter 142
- NOx Sensor 118
- Reductant Injector 107
- Exhaust Gas Temperature Sensor 95
- Reductant Tank 95
- Diesel Particulate Filter 76
- SCR Catalyst 65
- EGR Cooler 62
- Exhaust Gas Differential Pressure Sensor 58
- Fuel Tank Pressure Sensor 58
- Exhaust Pressure Control Valve 56
- Reductant Heater 55
- Reductant Pump 51
- EVAP Vent Valve 43
- Exhaust Aftertreatment Fuel Injector 42
- Charcoal Canister 33
- EGR Position Sensor 32
- Secondary Air Injection Pump 32
- Reductant Temperature Sensor 29
- EVAP Leak Detection Pump 29
- EVAP Purge Valve 27
- Particulate Matter Sensor 24
- Reductant Control Module 24
- Reductant Level Sensor 23
- Secondary Air Switching Valve 22
- EGR Temperature Sensor 21
- Secondary Air Check Valve 21
- Catalyst Heater 20
- Catalyst Temperature Sensor 20
- Fuel Filler Cap 18
- Reductant Quality Sensor 16
- Exhaust Back Pressure Sensor 15
- Purge Flow Sensor 13
- Direct Ozone Reduction Catalyst 13
- EGR Vacuum Solenoid 9
- Fuel Vapour Temperature Sensor 5
- Fuel Additive Control Module 4
- Fuel Additive Tank 4
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